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Journal Details
Format
Journal
eISSN
1899-7562
First Published
13 Jan 2009
Publication timeframe
5 times per year
Languages
English

Search

Volume 75 (2020): Issue 1 (October 2020)

Journal Details
Format
Journal
eISSN
1899-7562
First Published
13 Jan 2009
Publication timeframe
5 times per year
Languages
English

Search

23 Articles

Section I – Kinesiology

Open Access

Different Shoulder Exercises Affect the Activation of Deltoid Portions in Resistance-Trained Individuals

Published Online: 31 Oct 2020
Page range: 5 - 14

Abstract

Abstract

The aims of this study were to compare muscle activity of the anterior deltoid, medial deltoid, and posterior deltoid in the bench press, dumbbell fly, shoulder press, and lateral raise exercises. Thirteen men experienced in strength training volunteered for the study. Muscle activation was recorded during maximum isometric voluntary contraction (MVIC) for data normalization, and during one set of 12 repetitions with the load of 60% 1RM in all exercises proposed. One-way repeated-measures ANOVA with Bonferroni’s posthoc was applied using a 5% significance level. For anterior deltoid, the shoulder press (33.3% MVIC) presented a significantly higher level of activation when compared to other exercises. Also, no significant difference was found between the bench press (21.4% MVIC), lateral raise (21.2% MVIC), and dumbbell fly (18.8% MVIC). For the medial deltoid, the lateral raise (30.3% MVIC) and shoulder press (27.9% MVIC) presented a significantly higher level of activity than the bench press (5% MVIC) and dumbbell fly (3.4% MVIC). Besides, no significant difference was found between the bench press and the dumbbell fly. For the posterior deltoid, the lateral raise (24% MVIC) presented a significantly higher level of activation when compared to other exercises. For the posterior deltoid portion, the shoulder press (11.4% MVIC) was significantly more active than the bench press (3.5% MVIC) and dumbbell fly (2.5% MVIC). Moreover, no significant difference was found between the bench press and the dumbbell fly. In conclusion, the shoulder press and lateral raise exercises showed a higher level of muscle activation in the anterior deltoid and medial deltoid when compared to the bench press and dumbbell fly exercises.

Key words

  • EMG
  • strength training
  • glenohumeral joint
  • deltoid muscle
  • upper body
Open Access

Effect of Three Half-Squat Protocols on the Tensiomyographic Twitch Response and Tissue Damage of the Rectus Femoris and the Biceps Femoris

Published Online: 31 Oct 2020
Page range: 15 - 27

Abstract

Abstract

The aim of this study was to analyse the acute effects of a concentric exercise and two different eccentric overload exercises (EOEs) on blood markers of muscle damage (i.e. creatine kinase [CK], lactate dehydrogenase [LDH], myoglobin [Myo], and malondialdehyde [MDA]) and muscle contractile properties. Ten healthy, young (27 ± 1.5 years, 179 ± 6 cm, 78.7 ± 10.8 kg), physically active men (3.5 ± 1.9 h·w-1) randomly performed three training sessions using the following protocols: a half-squat (HS) as a concentric exercise, and exercises using Versapulley (VP) or YoYo isoinertial technology (YIT) as EOEs (4 x 7 repetitions with a 2 min rest interval between sets). Blood samples and tensiomyography measurements were obtained after each training session. Repeated measures analysis of variance (ANOVA) followed by the Tukey test was used to detect differences between the four time points of each variable. The standardized difference or effect size (ES, 90% confidence limit) in the selected variables was calculated using the basal SD. After all exercises, a greater activity of CK, LDH, and concentration of Myo, and MDA were found compared to baseline values (p < 0.05). A substantially greater activity of CK, LDH, and Myo concentration, but not MDA, were found after EOEs when compared to the HS protocol. Substantially lower tensiomyography results in the rectus femoris (RF) were reported, irrespective of the exercise mode performed. Also, no substantial differences were obtained in the biceps femoris (BF) between EOEs and the HS protocol. Time of contraction (Tc) in the RF was possibly to very likely lower in the HS in comparison to EOEs. Additionally, muscular displacement (Dm) in the RF was substantially lower in the HS compared to EOEs. VP produced higher concentrations of damage markers than YIT and concentric exercise did. Furthermore, tensiomyography variables showed similar activation in both exercises, although higher specific fatigue (in the RF) was registered in the traditional HS.

Key words

  • fatigue
  • musculoskeletal
  • performance
  • strength training
Open Access

The Effects of a 9-Week Hip Focused Weight Training Program on Hip And Knee Kinematics and Kinetics in Experienced Female Dancers

Published Online: 31 Oct 2020
Page range: 29 - 39

Abstract

Abstract

Increased involvement of the hip musculature during some movements is associated with enhanced performance and reduced injury risk. However, the impact of hip dominant weight training methods on movement strategy has seen limited attention within the literature. The aim of this study was to evaluate if a 9-week hip dominant weight training intervention promotes a more hip dominant movement strategy leading to an improvement in countermovement jump performance. Twenty-two experienced female dancers were recruited and separated into an intervention (age 24.4 ± 6.3 years, body height 165.5 ± 5.8 cm, body mass 65.9 ± 5.6 kg) and a control (age 22.9 ± 5.6 years, body height 163.3 ± 5.4 cm, body mass 57.4 ± 6.8 kg) group. The intervention group participated in a 9-week hip dominant training intervention, which consisted of a wide stance back squat, Romanian deadlift, hip thrusters, and a bent over row. Hip and knee kinematics and kinetics, and countermovement jump performance were assessed pre and post training. Significant interaction effects were found for peak hip joint moment (p = 0.030, η2 = 0.214) and countermovement jump performance (p = 0.003, η2 = 0.356), indicating an increase in peak hip joint moment and countermovement jump performance for the intervention group. Specifically, the intervention group showed a mean increase in jump height of 11.5%. The data show that the use of a hip dominant weight training strategy can improve hip contribution in the propulsion phase of the countermovement jump. Strength and conditioning specialists should incorporate hip dominant weight training exercises to increase hip strength and improve performance.

Key words

  • hip/knee dominance
  • vertical jump
  • movement strategy
  • strength training
  • performance
  • injury prevention
Open Access

The Structure of Selected Basic Acrobatic Jumps

Published Online: 31 Oct 2020
Page range: 41 - 64

Abstract

Abstract

The aim of this study was to investigate the relationships between the internal and external structure of basic acrobatic jumps. Eleven healthy elite artistic gymnasts (9 female, 2 male) participated in this study. Participants performed the following basic ‘acrobatic’ jumps: a tucked backward somersault (TS), a piked backward somersault (PS), and a countermovement jump (CMJ). Furthermore, female gymnasts also performed the backward handspring (HS), taking off and then landing on their hands in the same place – a specific jump only for women. All jumps were initiated from a stationary upright posture and with an arms swing. Six infrared cameras, synchronized with a module for wireless measurement of the electrical activity of eight muscles, and the force plate were used. Infrared camera-recordings were made in order to obtain kinematic variables describing the movement structure of the acrobatic jumps. These variables may explain the characteristics of muscle activation (the internal structure of the movement) and ground reaction force (the external-kinetic structure of the movement). However, for various technical reasons, it was not possible to register all the specified jumps in the protocol. Moreover, the distribution normalities, estimated by the Kolmogorov-Smirnov test, differed between variables. Therefore, to compare the data, the pair-wise nonparametric Wilcoxon Signed-Ranks Test was applied. The CMJ showed the highest level of vertical impulse, velocity, and displacement followed by the TS, PS, and HS. In the take-off phase of acrobatic jumps with rotation the average muscle activation levels of the biceps femoris were significantly higher and of the rectus femoris significantly lower than in the countermovement jump.

Key words

  • Smart-E measuring system
  • gymnastics
  • movement structure
  • movement analysis
Open Access

Influence of Attentional Manipulation on Jumping Performance: A Systematic Review and Meta-Analysis

Published Online: 31 Oct 2020
Page range: 65 - 75

Abstract

Abstract

Enhancing jumping ability can lead to substantial benefits in sports performance and physical activity. Previous studies indicate that directing an individual’s attention externally before the jump is an effective way to improve jumping performance, especially when the standing long jump (SLJ) and vertical jumps (VJs) are performed. To scrutinize reported findings, we systematically reviewed studies that compared the effects of attentional manipulations on jumping performance in adults. Four electronic databases (MEDLINE, Scopus, SPORTSDiscus, and Web of Science) were searched for original research publications. A priori defined inclusion criteria were: (a) participants were healthy adults with a mean age > 18 years, (b) an external (EF) or an internal focus (IF) of attention instruction was used, (c) the study compared an external focus intervention with an internal focus intervention or an external focus with a control (no attentional; CON) intervention or an internal focus intervention with a control intervention, (d) jumping performance was tested, and (e) an immediate effect of focus of attention intervention was evaluated. Of the 380 papers identified, 14 studies were used in 3 part meta-analyses (EF vs. IF, EF vs. CON, and IF vs. CON) that involved 24 comparisons in total. The findings of this analysis revealed that the EF condition displayed superior jumping performance relatively to the IF (p < 0.05) and CON (p < 0.05) conditions. There were no significant (p > 0.05) differences between the IF and CON conditions. These findings suggest that EF instructions should be incorporated into testing procedures when jumping performance is assessed.

Key words

  • jump testing
  • external focus of attention
  • internal focus of attention
  • standing long jump
  • vertical jump
  • instructions

Section II – Exercise Physiology & Sports Medicine

Open Access

Predicting the 2000‐m Rowing Ergometer Performance from Anthropometric, Maximal Oxygen Uptake and 60‐s Mean Power Variables in National Level Young Rowers

Published Online: 31 Oct 2020
Page range: 77 - 83

Abstract

Abstract

Many studies reported various relationships between 2000-m rowing performance and anthropometric as well as metabolic variables, however, little is known about 60-s mean power in elite youth athletes. The aim of this study was to develop different regression models to predict 2000-m rowing indoor performance time (t2000) using anthropometric variables, maximal oxygen uptake (VO2max) and mean power established during a 60-s all-out test (W60) in national elite youth rowers. Fifteen youth male Italian rowers (age: 15.7 ± 2.0 years; body height: 176.0 ± 8.0 cm; body mass: 71.2 ± 10.0 kg) performed an incremental maximal test, a 60-s all-out test and a 2000-m race simulation using a Concept2 rowing ergometer to assess VO2max, W60 and t2000, respectively. The relationships of all variables with t2000 were investigated through Pearson’s correlation. Multiple regression analyses were used to verify the best prediction model of 2000-m indoor rowing performance. The reliability of these models was expressed by R2 and the standard error of estimate. The results showed that t2000 was significantly correlated with all the examined variables, except for VO2max/body mass and age, and exhibited the significantly highest relationship with W60 (r = -0.943). The combination of anthropometric, VO2max and W60 variables was found to be the most reliable equation to predict t2000 (R2 = 0.94, SEE = 6.4). W60 measure should be considered when monitoring the rower’s capability to perform high-intensity phases, important during the race’s fast start and end. Not requiring expensive equipment and long duration, a 60-s all-out test could be considered a valuable tool for predicting 2000-m performance of elite youth rowers.

Key words

  • elite youth athletes
  • mean power
  • indoor rowing
  • anthropometric variables
  • VO
  • rowing performance
Open Access

Acute Effect of Sodium Bicarbonate Supplementation on Symptoms of Gastrointestinal Discomfort, Acid‐Base Balance, and Performance of Jiu‐Jitsu Athletes

Published Online: 31 Oct 2020
Page range: 85 - 93

Abstract

Abstract

The purpose of the present study was to verify the acute effect of sodium bicarbonate supplementation on symptoms of gastrointestinal discomfort, acid-base balance and intermittent isometric handgrip test performance in Jiu-Jitsu athletes. Ten male (22.2 ± 3.9 years; 174 ± 0.07 cm; 74.5 ± 8.9 kg) jiu-jitsu athletes participated in this counterbalanced double-blind crossover study. Two protocols, a) supplementation with 0.3 g.kg-1 of body weight of sodium bicarbonate, and b) supplementation with 0.045 g.kg-1 of body weight of placebo substance, were employed. Gastrointestinal tolerability was assessed by the questionnaire. Blood samples were collected at three time points (baseline, pre-ISO, and post-ISO) to determine the responses of potential hydrogenionic (pH), bicarbonate (HCO3-), base excess (EB) and lactate concentrations. The maximum voluntary contraction test and the intermittent isometric contraction test were also performed. As a result, none of the athletes reported significant gastrointestinal discomfort (p > 0.05). HCO3-, pH, and EB at the pre-ISO and post-ISO moments were significantly higher for the sodium bicarbonate protocol. Lactate concentrations were significantly higher for both post-ISO protocols (p = 0.000). There was no significant difference in the performance of the maximum voluntary contraction test and the intermittent isometric contraction test (p > 0.05). Thus, we conclude that sodium bicarbonate supplementation does not generate adverse responses resulting in gastrointestinal discomfort, and does not benefit performance yet promotes a state of metabolic alkalosis.

Key words

  • NaHCO
  • metabolic alkalosis
  • martial arts
  • handgrip exercise
  • intermittent exercise
Open Access

Acute Physiological Responses to Ultra Short Race‐Pace Training in Competitive Swimmers

Published Online: 31 Oct 2020
Page range: 95 - 102

Abstract

Abstract

Ultra Short Race Pace training (USRPT) is an emerging training modality devised in 2011 to deviate from high-volume swimming training that is typically prescribed. USRPT aims to replicate the exact demands of racing, through its unique prescription of race-pace velocity sets with short rest intervals. It has been surmised, with little physiological evidence, that USRPT provides swimmers with the best opportunity to optimize the conditioning, technique, and psychology aspects of racing at the most specific velocity of the relevant event, with low blood lactate concentration. The aim of this study was to examine acute physiological responses of USRPT. Fourteen swimmers were recruited to perform a USRPT set: 20 x 25 m freestyle with a 35-s rest interval. Swimmers were required to maintain the velocity of their 100 m personal best time for each sprint. Sprint performance, blood lactate, heart rate and the RPE were measured. Blood lactate was taken before, during (after every 4 sprints) and 3 minutes after the USRPT protocol. Heart rate monitors were used to profile the heart rate. Athletes reported the RPE before- and after completion of the USRPT set. Sprint times increased by 3.3-10.8% when compared to the first sprint (p < 0.01). There was high blood lactate concentration (13.6 ± 3.1mmol/l), a significant change in the RPE from 8 ± 1.6 to 18 ± 1.6 (p < 0.01) and a substantially high heart rate profile with an average HRmax of 188 ± 9 BPM. The results show the maximal intensity nature of USRPT and portray it as an anaerobic style of training.

Key words

  • swimming
  • high-intensity
  • heart-rate
  • blood-lactate
  • sprinting
  • and performance
Open Access

Shoulder Muscle Imbalance as a Risk for Shoulder Injury in Elite Adolescent Swimmers: A Prospective Study

Published Online: 31 Oct 2020
Page range: 103 - 113

Abstract

Abstract

Muscle strength imbalances between the internal and external rotators of the shoulder are frequent in swimmers, but their role in shoulder injury remains unknown. We aimed to evaluate the association of shoulder rotator strength and injury in elite adolescent swimmers. Eighteen adolescent swimmers performed preseason isokinetic tests of the internal and external rotator muscles in concentric (con) and eccentric (ecc) modes. Conventional (conER:conIR and eccER:eccIR) and functional ratios (eccER:conIR and eccIR:conER) were calculated. Thirteen swimmers completed a weekly questionnaire about swimming habits and shoulder injuries throughout the season. Preseason testing showed a significant negative association between the functional eccER:conIR ratio and years of practice (p < 0.05). Over the season, 46% of athletes experienced at least one shoulder injury. At the end of the season, peak torques increased for both internal and external rotator muscles strength, but only concentrically, resulting in a decrease in the eccER:conIR functional ratio (p < 0.05). The receiver operating characteristic curve analysis highlighted good predictive power for the preseason functional eccER:conIR ratio, as values below 0.68 were associated with a 4.5-fold (95% CI 1.33-15.28, p < 0.05) increased risk of shoulder injuries during the season.

Key words

  • swimming
  • sports injury prevention
  • isokinetic testing
  • strength imbalance
Open Access

The Relationship Between Repeated‐Sprint Ability, Aerobic Capacity, and Oxygen Uptake Recovery Kinetics in Female Soccer Athletes

Published Online: 31 Oct 2020
Page range: 115 - 126

Abstract

Abstract

This study investigated the relationship between repeated-sprint ability, aerobic capacity, and oxygen uptake kinetics during the transition between exercise and recovery (off-transient) in female athletes of an intermittent sport modality. Eighteen professional soccer players completed three tests: 1) a maximal incremental exercise test; 2) a constant speed time-to-exhaustion test; and 3) a repeated-sprint ability test consisting of six 40-m sprints with 20 s of passive recovery in-between. Correlations between time-to-exhaustion, repeated-sprint ability, and oxygen uptake kinetics were calculated afterwards. The level of significance was set at p < 0.05. A performance decrement during repeated-sprint ability was found to be related to: 1) time-to-exhaustion (e.g., exercise tolerance; r = -0.773, p < 0.001); 2) oxygen uptake recovery time (r = 0.601, p = 0.008); and 3) oxygen uptake mean response time of recovery (r = 0.722, p < 0.001). Moreover, the best sprint time (r = -0.601, p = 0.008) and the mean sprint time (r = -0.608, p = 0.007) were found to be related to maximal oxygen uptake. Collectively, these results reinforce the relation between oxygen uptake kinetics and the ability to maintain sprint performance in female athletes. These results may contribute to coaches and training staff of female soccer teams to focus on training and improve their athletes’ aerobic capacity and recovery capacity to improve intermittent exercise performance.

Key words

  • oxygen uptake kinetics
  • sprinting ability
  • intermittent modality
  • women soccer
  • women athletes
Open Access

Influence of Inspiratory Muscle Training of Various Intensities on The Physical Performance of Long‐Distance Runners

Published Online: 31 Oct 2020
Page range: 127 - 137

Abstract

Abstract

The aim of this study was to assess the efficacy of inspiratory muscle training (IMT) at different intensities on the pulmonary function and physiological adaptations of long-distance runners undergoing sports training. This study involved 25 long-distance runners. The subjects were randomly divided into three groups depending on the type of IMT applied: POWERbreathe device (group 1), Threshold IMT device (group 2), and a control group. The following lung variables were evaluated: vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF). Respiratory muscle strength was assessed by maximum inspiratory pressure (PImax) and maximum expiratory pressure (PEmax). Spiroergometric measures included: heart rate (HR), oxygen uptake (VO2max), carbon dioxide production (VCO2max), maximum ventilation (VE) and respiratory exchange rate (RER), which were measured breath by breath using a gas analyser (VYNTUS CPX). Group 1, which used the POWERbreathe device, showed significant increases in all assessed physiological and physical performance variables. In group 2, which used the Threshold device, only VO2max, VE and tRER ventilation were significantly increased to a similar level as that observed in group 1. In the control group, we only observed a significant reduction in saturation. The use of IMT with a higher intensity resulted in significant improvements in all tested variables of lung ventilation and respiratory muscle strength. Also, after training, lactate accumulation was significantly decreased. Physiological characteristics (VO2max/kg) and muscle respiratory strength variables were significantly improved in the group that used the POWERbreathe device after 8 weeks of training.

Key words

  • inspiratory muscle training
  • runners
  • pulmonary function
  • physiological adaptations
Open Access

The Immediate Effects of Self‐Myofacial Release on Flexibility, Jump Performance and Dynamic Balance Ability

Published Online: 31 Oct 2020
Page range: 139 - 148

Abstract

Abstract

Self-myofascial release (SMR) is a popular method to potentially increase the compliance and extensibility of the fascia and reduce muscle stiffness. The purpose of this study was to examine the acute effects of posterior muscle chain SMR on flexibility, vertical jump performance and balance ability. Eighteen young participants volunteered to take part in this crossover design study. They performed two self-massage sessions in randomized order separated by at least one week. One session consisted of posterior muscle chain SMR whereas the other one was performed on the upper limbs as a control intervention (CON). Flexibility was measured with the Toe Touch Test (TTT), Weight-Bearing Lunge Test (WBLT), and Straight Leg Raise Test (SLR). Jump performance was evaluated during a squat jump, a counter movement jump and a stiffness jump. Dynamic balance ability was assessed through the Star Excursion Balance Test. All these variables were measured before and after each intervention. A significant increase in flexibility (+3.5 ± 1.8 cm, +1.6 ± 1.0°, and +7.7 ± 4.0° for the TTT, WLBT, and SLR, respectively, p < 0.003) and balance performance (4.8 ± 3.9 cm, p < 0.003) was observed following SMR intervention compared to CON. Conversely, jumping performance was unchanged in both groups. SMR improves joint flexibility and dynamic balance ability.

Key words

  • roller massage
  • foam rolling
  • range of motion
  • jumping performance
  • balance ability

Section III – Sports Training

Open Access

The Relative Age Effect at the Ice Hockey World Championships (IHWC) in the years 2015–2017

Published Online: 31 Oct 2020
Page range: 150 - 159

Abstract

Abstract

The relative age effect (RAE) theory is based on the premise that athletes born in the first months of the calendar year have a significant probability of a higher level of physiological, morphological and psychological abilities compared to later-born athletes. The aim of our study was to verify the influence of the RAE on adult ice hockey players, specifically Ice Hockey World Championships’ (IHWC) participants in the years 2015−2017 (n = 1,200). Based on the chi-squared (χ2) analysis, the influence of the RAE during the 2015−2017 period could not be rejected for all observed players (χ2 = 54.6, p < 0.01, w = 0.21) or for all the players for particular years (2015, 2016, and 2017; p < 0.01). During the monitored period (2015−2017), the RAE could not be rejected for any player’s position (forward, defender, or goaltender). Based on the effect size analysis (Cohen’s w), the strongest RAE was observed among goaltenders (w = 0.31), then forwards (w = 0.24) and finally defenders (w = 0.15). The assessment of player’s positions in particular years showed statistical significance for goaltenders only in 2015 (χ2 = 11.3, p < 0.05). With regard to forwards, significance was confirmed for 2015 (χ2 = 8.5, p < 0.05), 2016 (χ2 = 15.2, p < 0.01) and 2017 (χ2 = 14.3, p < 0.01). Therefore, the presence of the RAE could not be rejected for all these cases. The results of the research show that members of national teams in the years 2015−2017 were players who were chronologically older, which is consistent with the results of other authors addressing the RAE.

Key words

  • athletic talent
  • birthdate
  • national teams
  • player’s position
Open Access

Relationships Between Measures of Functional and Isometric Lower Body Strength, Aerobic Capacity, Anaerobic Power, Sprint and Countermovement Jump Performance in Professional Soccer Players

Published Online: 31 Oct 2020
Page range: 161 - 175

Abstract

Abstract

The purpose of this study was to assess a wide range of physiological and performance variables and investigate whether and to what extent these variables are associated with each other in soccer. Twenty-five male soccer players (25.1 ± 4.56 years; body mass, 75.2 ± 5.92 kg; body height, 180.6 ± 5.45 cm) performed: 5- and 30-m sprints (T5m and T30m, respectively), 1-repetition-maximum (1RM) half squat, maximal voluntary isometric contraction (MVIC) of the knee extensors, countermovement jump (CMJ) to obtain vertical jump height (CMJheight) and power output (CMJpower), the 10-s Wingate Anaerobic Test (WAnT) to obtain peak power (Pmax), and the 20-m multi-stage shuttle run test (MST) to evaluate aerobic capacity. 1RM, MVIC, and Pmax were normalized to body mass. Large negative correlations were found between sprint times and 1RM half back squat/BM (r = -0.510 to -0.570, r2 = 0.260–0.325, both p < 0.01) and Pmax/BM (r = -0.501, r2 = 0.251, p < 0.01). T30m most strongly and negatively correlated with CMJheight (r = -0.744, r2 = 0.554, p < 0.001). WAnT-determined Pmax showed a very large correlation between absolute Pmax and knee-extensor MVIC (r = 0.827, r2 = 0.684, p < 0.001) and large correlations between absolute Pmax and 1RM half squat (r = 0.674, r2 = 0.454, p < 0.001) and CMJpower (r = 0.579, r2 = 0.335, p < 0.01). We also identified a large inverse relationship between CMJheight and T30m (r = -0.744, r2 = 0.554, p < 0.001) and large positive correlation between CMJheight and MVIC/BM (r = 0.702, p < 0.001). The results demonstrate that elite soccer players with greater lower body strength (quantified by the MVIC of the knee extensor and the 1RM half squat) show better sprint and CMJ performance, suggesting the incorporation of soccer-specific resistance training to develop lower body musculature and therefore maximize sprinting ability. The higher correlation coefficients found between T30m and the physiological and athletic measures compared with T5m promote the use of this sprint distance when assessing performance. The use of relative measures (normalized to body mass) is advisable when comparing strength variables with sprint and CMJ performance or anaerobic power. Considering the correlations of WAnT-determined Pmax versus CMJpower, coaches should administer tests that assess jumping and linear sprint performance rather than the cycling-specific WAnT.

Key words

  • static and dynamic muscular strength
  • sprinting ability
  • acceleration
  • physiological response
  • endurance shuttle run
  • competitive soccer
Open Access

Statistical Comparison of Singles Badminton Matches at the London 2012 and Rio De Janeiro 2016 Olympic Games

Published Online: 31 Oct 2020
Page range: 177 - 184

Abstract

Abstract

The aim of this study was to analyse statistical differences in men’s and women’s singles badminton competitions at the London and Rio Olympic Games. Forty-five matches (128 sets in total) played at the 2012 and 2016 Olympics in badminton were analysed. Variables related to the match (6) and each set (13) were determined. The results show the longest rally in sets 1 and 3, the biggest come back to win the game in set 2, and that the duration of set 3 for men was longer in Rio than in London. All of the women’s sets had longer duration, and the rally length and the number of strokes per rally was also longer in Rio versus London. In conclusion, the timing factors of badminton singles were dissimilar in London 2012 and Rio 2016 for both men and women. This information may help players and coaches manage different workout types or, more specifically, competition schedules that are adapted to suit modern badminton’s characteristics.

Key words

  • racket sport
  • notational analysis
  • elite performance
Open Access

The Explanatory Capacity of Talent Identification Tests for Performance in Triathlon Competitions: A Longitudinal Analysis

Published Online: 31 Oct 2020
Page range: 185 - 193

Abstract

Abstract

The aim of this study was to determine the explanatory capacity of the Spanish Triathlon Federation’s talent identification tests in relation to performance in competition in subsequent years. We used an exploratory longitudinal study design to establish the relationship between talent identification tests completed by 247 triathletes (97 women and 150 men) aged from 14 to 19 years and the results they obtained over the years in competition. The battery of tests included freestyle swimming (100 and 1000 m) and running (400 and 1000 m). The results indicate that the explanatory capacity of these tests for split places in competition in the corresponding discipline was highest in the 1000-m swimming test, with a value of 0.34 for the adjusted coefficient of determination (R2a) (p ≤ 0.001), followed by the 1000-m running and 100-m swimming tests, where the highest R2a values were 0.26 and 0.19, respectively. No significant model was found for the 400-m running test. It was concluded that the explanatory capacity of the tests analysed for predicting performance in the discipline in competition was low. However, it was higher for the swimming and running tests of longer distance.

Key words

  • talent identification
  • sports performance
  • triathlon performance
  • endurance sports
  • youth sports
  • exercise tests
Open Access

Match and Training High Intensity Activity-Demands Profile during a Competitive Mesocycle in Youth Elite Soccer Players

Published Online: 31 Oct 2020
Page range: 195 - 205

Abstract

Abstract

The monitoring of the high intensity activity-demands profile during official matches (OMs) and training sessions (TSs) provides a deeper understanding of the relationship between training and competition loads as well as players’ fitness characteristics. The aims of this study were to: 1) describe the training and match high intensity activity-demands profile in U-19 soccer players; 2) compare the profile depending on the type of session (OM or TS) throughout match-weeks; and 3) differentiate between profiles depending on the match location (home or away). Twenty-five U-19 Spanish soccer players were monitored during TSs and OMs for a one-month competitive period using a WIMU PROTM wearable inertial device. The variables of the study were: high speed running distance (HSRD), total sprints (SPs), maximum speed (MS) and player load (PL). OMs required higher demands than TSs in HSRD (460.99 ± 206.18 vs. 315.45 ± 180.12 m; p < 0.01; d = 0.75), SPs (10.86 ± 6.64 vs. 7.23 ± 4.82; p < 0.01; d = 0.69), MS (29.99 ± 2.54 vs. 28.50 ± 2.4 km/h; p < 0.01; d = 0.59) and PL (103.08 ± 24.15 vs. 83.18 ± 17.96 a.u.; p < 0.01; d = 0.94). The interaction between the type of session and mean week’s demands presented differences with medium effect size in MS (p < 0.01; ωp2 = 0.06) and small effect size in HSRD (p = 0.04; ωp2 = 0.03), and SP (p = 0.05; ωp2 = 0.03), but there were no differences in PL (p = 0.18; ωp2 = 0). Finally, no differences were found in the match location comparison (p > 0.33; d = 0.22–0.33). Therefore, the profiles presented could be useful for future scientific purposes and serve as valid information for coaches trying to optimize performance.

Key words

  • workload
  • competition
  • team sports
  • inertial devices
  • performance
Open Access

A Systematic Review of the Batting Backlift Technique in Cricket

Published Online: 31 Oct 2020
Page range: 207 - 223

Abstract

Abstract

There has been an extensive amount of research into the batting elements of cricket. However, there is limited research specifically on the batting backlift technique (BBT). Therefore, this review aims to provide an understanding and consensus of the BBT in cricket at varied skilled levels. A PRISMA flow chart revealed 38 studies that were reviewed (both coaching and scientific literature), which reported on the backlift in cricket. The databases searched were PubMed, Google Scholar, the Cochrane Library and Sabinet. This review shows that the lateral batting backlift technique (LBBT) is a likely contributing factor to successful batsmanship at all levels of cricket ability (junior, adolescent, semi-professional, professional, international and former elite/successful cricketers). It was also found that coaching a LBBT to young batsmen may be challenging to teach, and therefore, further coaching models should be developed to assist cricket coaches. As much as a LBBT may be a contributing factor for success, there is still a need to answer a number of questions through further in-depth biomechanical investigations and through interventions that are more meticulous. A way forward for further research in this area of cricket batting is documented at the end of the review.

Key words

  • biomechanics
  • performance analysis
  • coaching
  • batters
  • cricketers
Open Access

Tactical Behaviour of Youth Soccer Players: Differences Depending on Task Constraint Modification, Age and Skill Level

Published Online: 31 Oct 2020
Page range: 225 - 238

Abstract

Abstract

This study aimed to investigate: i) how Small-Sided and Conditioned Games based on different representation and exaggeration modification strategies, from the Teaching Games for Understanding pedagogical principles, affected team performance and exploratory behaviour; and ii) how teams and players of different ages and skill levels were affected by the use of these different modification strategies. In total, forty-eight youth male soccer players participated in the study (U15, n = 24 mean age = 13.06 ± 1.53 years; U17, n = 24 mean age = 16.89 ± 0.11 years). In both categories, players were organized into three groups according to their tactical efficiency level (Group 01 = High Skilled Players (HSP), Group 02 = Intermediate Skilled Players (ISP), and Group 03 = Low Skilled Players (LSP)). The HSP and LSP groups performed two types of Gk+4vs4+Gk Small-Sided and Conditioned Games (SSCGs) based on different representation and exaggeration modification strategies. The first type of SSCGs was modified by structural constraints (Structural SSCG) and the second type was modified by rule manipulation (Manipulation SSCG). Team performance and exploratory behaviour were analysed through the Offensive Sequences Characterization System and Lag Sequential Analysis, respectively. SSCG modification strategies affected differently tactical performance and exploratory behaviour of teams composed of players of different skill levels. It was found that SSCG modification strategy through rule manipulation provided players and teams with a higher level of difficulty, compromising their performance and inhibiting exploratory behaviour. This information is crucial to practitioners wishing to apply more appropriate pedagogical strategies to improve a specific tactical problem using a player-centred and game-based approach.

Key words

  • nonlinear pedagogy
  • pedagogical principles
  • tactical skills
  • performance level
  • complexity
Open Access

Muscle Activity Asymmetry of the Lower Limbs During Sprinting in Elite Soccer Players

Published Online: 31 Oct 2020
Page range: 239 - 245

Abstract

Abstract

The analysis of movement patterns through EMG activity provides the opportunity to identify the muscle groups most involved in a particular exercise, and to determine the scope of inter-limb deficiencies. The aim of the present study was to investigate the effects of a side-to-side muscle activity asymmetry between the left and the right lower limb during sprinting in soccer players. Sixteen professional soccer players took part in the study. Their age, body mass and body height equaled 23.7 ± 7.6 years, 81.2 ± 10.8 kg and 179.3 ± 12.2 cm, respectively. The sprint test consisted of two maximal sprints over 30 m with a 5-min rest interval between each sprint. EMG was recorded bilaterally from the quadriceps, hamstrings and gluteal muscles. Regression analysis revealed a significant effect of a side-to-side average muscle activity asymmetry between the left and right hamstring (LH/RH) muscles during the speed tests at 5 m (p = 0.044), and 30 m (p = 0.045), as well as the left and right glutes (LG/RG) at 5 m (p = 0.044) and 30 m (p = 0.043). Our results indicate that hamstring and glute muscles should be selectively and additionally activated during resistance training in soccer players to prevent injuries and improve sprint performance.

Key words

  • soccer
  • EMG
  • sprinting
  • movement pattern
Open Access

Comparisons of Motor Actions and Biomechanical Assessments of Judo Techniques Between Female Weight Categories

Published Online: 31 Oct 2020
Page range: 247 - 255

Abstract

Abstract

This study aimed to perform motor action and biomechanical analysis of techniques in female judo athletes separated by weight categories of 638 female bouts (103 extra lightweight <48 kg, 140 half lightweight 48>52 kg, 65 lightweight 52>57 kg, 73 half middleweight 57>63 kg, 77 middleweight 63>70 kg, 80 half heavyweight 70>78 kg and 60 heavyweight >78 kg). All bouts were analyzed following the phases of approach, gripping, defensive action, attack, also biomechanical analysis of techniques and groundwork was performed (p ≤ .05). Results indicated that lightweight athletes presented lower attempts to grip, right collar grip and left collar grip frequencies than other categories. Extra lightweight judokas presented lower right back grip and left back and sleeve grip frequencies as well as lower occurrence of techniques with arm and leg lever scored than half lightweight athletes, while half lightweight athletes demonstrated higher frequency of techniques with waist lever variable scored than lightweight ones. These findings should be considered for training prescription.

Key words

  • time and motion analysis
  • biomechanical analysis
  • task performance and analysis
  • martial arts
  • motor control
  • training
Open Access

Differences in External Load Variables Between Playing Positions in Elite Basketball Match-Play

Published Online: 31 Oct 2020
Page range: 257 - 266

Abstract

Abstract

The purpose of this study was to describe the specific demands and structure of interrelationships of external load variables in order to generate a position-related time motion profile in elite basketball. Seventeen professional players from three different playing positions (6 guards, 4 forwards, and 7 centers) were analyzed in five friendly games. Player load per minute (PLmin) was used as an indicator of intensity to compare positions. Furthermore, high and total external variables of jumping (hJUMP and tJUMP), acceleration (hACC and tACC), deceleration (hDEC and tDEC) and change of direction (hCOD and tCOD), respectively, were used for the principal component analysis (PCA). The Kaiser criterion (eigenvalue > 1) was applied, and the Varimax rotation mode was used to extract multiple principal components. PCA showed that all positions had three or four principal components, but the configuration of each factor was different: tCOD, hCOD, hDEC and hJUMP for guards, hCOD, tCOD, tACC and hDEC for forwards, and tJUMP, hJUMP, hDEC and tACC for centers were specifically demanded in match-play. For guards and forwards, a significant correlation was found between COD variables, while for centers tCOD and PLmin had the strongest correlation. When monitoring the external load via tri-axial accelerometers in basketball match-play, each playing position showed specific physical demands. Therefore, these variables must be prioritized in load monitoring programs.

Key words

  • playing position
  • team sport
  • time motion
  • basketball
  • PCA
  • game load
Open Access

Effects of Ischemic Preconditioning as a Warm-Up on Leg Press and Bench Press Performance

Published Online: 31 Oct 2020
Page range: 267 - 277

Abstract

Abstract

Ischemic preconditioning (IPC) has been used to increase performance in sports. The aim of this study was to compare the acute effects of IPC with different warm-up methods on the number of repetitions and total volume in resistance exercise (RE). Sixteen healthy men recreationally trained in RE participated in this study. After the anthropometric evaluation and familiarization, a one-repetition maximum (1RM) test and retest were performed in the bench press (BP) and in the leg press 45° (LP) exercise. After these tests, participants were randomly assigned to one of the five protocols: a) IPC; b) SHAM; c) a specific warm-up (SW); d) aerobic exercise (AE), and e) active stretching (AS) prior to performing 3 sets at 80% 1RM until concentric failure. The number of repetitions was higher following IPC compared to the SW following three sets both for the BP and LP. Similarly, the number of repetitions for IPC was higher in comparison to SHAM following three sets for the LP. The number of repetitions was higher following IPC compared to AE following 1st and 2nd sets for the LP and following the 2nd set for the BP. Finally, the number of repetitions was higher following IPC compared to AS following 1st and 2nd sets for the LP. The total volume was higher following IPC compared to SHAM, SW, AE, and AS for both the BP and LP. The IPC protocol increased the number of maximum repetitions and the total volume when compared to the other tested methods, thus indicating a better utilization during the pre-work warm-up. These results indicate positive associative responses to IPC with performance maintenance, which is of importance for both athletes and coaches.

Key words

  • ischemic preconditioning
  • resistance exercise
  • warm-up
  • performance
  • ischaemia
23 Articles

Section I – Kinesiology

Open Access

Different Shoulder Exercises Affect the Activation of Deltoid Portions in Resistance-Trained Individuals

Published Online: 31 Oct 2020
Page range: 5 - 14

Abstract

Abstract

The aims of this study were to compare muscle activity of the anterior deltoid, medial deltoid, and posterior deltoid in the bench press, dumbbell fly, shoulder press, and lateral raise exercises. Thirteen men experienced in strength training volunteered for the study. Muscle activation was recorded during maximum isometric voluntary contraction (MVIC) for data normalization, and during one set of 12 repetitions with the load of 60% 1RM in all exercises proposed. One-way repeated-measures ANOVA with Bonferroni’s posthoc was applied using a 5% significance level. For anterior deltoid, the shoulder press (33.3% MVIC) presented a significantly higher level of activation when compared to other exercises. Also, no significant difference was found between the bench press (21.4% MVIC), lateral raise (21.2% MVIC), and dumbbell fly (18.8% MVIC). For the medial deltoid, the lateral raise (30.3% MVIC) and shoulder press (27.9% MVIC) presented a significantly higher level of activity than the bench press (5% MVIC) and dumbbell fly (3.4% MVIC). Besides, no significant difference was found between the bench press and the dumbbell fly. For the posterior deltoid, the lateral raise (24% MVIC) presented a significantly higher level of activation when compared to other exercises. For the posterior deltoid portion, the shoulder press (11.4% MVIC) was significantly more active than the bench press (3.5% MVIC) and dumbbell fly (2.5% MVIC). Moreover, no significant difference was found between the bench press and the dumbbell fly. In conclusion, the shoulder press and lateral raise exercises showed a higher level of muscle activation in the anterior deltoid and medial deltoid when compared to the bench press and dumbbell fly exercises.

Key words

  • EMG
  • strength training
  • glenohumeral joint
  • deltoid muscle
  • upper body
Open Access

Effect of Three Half-Squat Protocols on the Tensiomyographic Twitch Response and Tissue Damage of the Rectus Femoris and the Biceps Femoris

Published Online: 31 Oct 2020
Page range: 15 - 27

Abstract

Abstract

The aim of this study was to analyse the acute effects of a concentric exercise and two different eccentric overload exercises (EOEs) on blood markers of muscle damage (i.e. creatine kinase [CK], lactate dehydrogenase [LDH], myoglobin [Myo], and malondialdehyde [MDA]) and muscle contractile properties. Ten healthy, young (27 ± 1.5 years, 179 ± 6 cm, 78.7 ± 10.8 kg), physically active men (3.5 ± 1.9 h·w-1) randomly performed three training sessions using the following protocols: a half-squat (HS) as a concentric exercise, and exercises using Versapulley (VP) or YoYo isoinertial technology (YIT) as EOEs (4 x 7 repetitions with a 2 min rest interval between sets). Blood samples and tensiomyography measurements were obtained after each training session. Repeated measures analysis of variance (ANOVA) followed by the Tukey test was used to detect differences between the four time points of each variable. The standardized difference or effect size (ES, 90% confidence limit) in the selected variables was calculated using the basal SD. After all exercises, a greater activity of CK, LDH, and concentration of Myo, and MDA were found compared to baseline values (p < 0.05). A substantially greater activity of CK, LDH, and Myo concentration, but not MDA, were found after EOEs when compared to the HS protocol. Substantially lower tensiomyography results in the rectus femoris (RF) were reported, irrespective of the exercise mode performed. Also, no substantial differences were obtained in the biceps femoris (BF) between EOEs and the HS protocol. Time of contraction (Tc) in the RF was possibly to very likely lower in the HS in comparison to EOEs. Additionally, muscular displacement (Dm) in the RF was substantially lower in the HS compared to EOEs. VP produced higher concentrations of damage markers than YIT and concentric exercise did. Furthermore, tensiomyography variables showed similar activation in both exercises, although higher specific fatigue (in the RF) was registered in the traditional HS.

Key words

  • fatigue
  • musculoskeletal
  • performance
  • strength training
Open Access

The Effects of a 9-Week Hip Focused Weight Training Program on Hip And Knee Kinematics and Kinetics in Experienced Female Dancers

Published Online: 31 Oct 2020
Page range: 29 - 39

Abstract

Abstract

Increased involvement of the hip musculature during some movements is associated with enhanced performance and reduced injury risk. However, the impact of hip dominant weight training methods on movement strategy has seen limited attention within the literature. The aim of this study was to evaluate if a 9-week hip dominant weight training intervention promotes a more hip dominant movement strategy leading to an improvement in countermovement jump performance. Twenty-two experienced female dancers were recruited and separated into an intervention (age 24.4 ± 6.3 years, body height 165.5 ± 5.8 cm, body mass 65.9 ± 5.6 kg) and a control (age 22.9 ± 5.6 years, body height 163.3 ± 5.4 cm, body mass 57.4 ± 6.8 kg) group. The intervention group participated in a 9-week hip dominant training intervention, which consisted of a wide stance back squat, Romanian deadlift, hip thrusters, and a bent over row. Hip and knee kinematics and kinetics, and countermovement jump performance were assessed pre and post training. Significant interaction effects were found for peak hip joint moment (p = 0.030, η2 = 0.214) and countermovement jump performance (p = 0.003, η2 = 0.356), indicating an increase in peak hip joint moment and countermovement jump performance for the intervention group. Specifically, the intervention group showed a mean increase in jump height of 11.5%. The data show that the use of a hip dominant weight training strategy can improve hip contribution in the propulsion phase of the countermovement jump. Strength and conditioning specialists should incorporate hip dominant weight training exercises to increase hip strength and improve performance.

Key words

  • hip/knee dominance
  • vertical jump
  • movement strategy
  • strength training
  • performance
  • injury prevention
Open Access

The Structure of Selected Basic Acrobatic Jumps

Published Online: 31 Oct 2020
Page range: 41 - 64

Abstract

Abstract

The aim of this study was to investigate the relationships between the internal and external structure of basic acrobatic jumps. Eleven healthy elite artistic gymnasts (9 female, 2 male) participated in this study. Participants performed the following basic ‘acrobatic’ jumps: a tucked backward somersault (TS), a piked backward somersault (PS), and a countermovement jump (CMJ). Furthermore, female gymnasts also performed the backward handspring (HS), taking off and then landing on their hands in the same place – a specific jump only for women. All jumps were initiated from a stationary upright posture and with an arms swing. Six infrared cameras, synchronized with a module for wireless measurement of the electrical activity of eight muscles, and the force plate were used. Infrared camera-recordings were made in order to obtain kinematic variables describing the movement structure of the acrobatic jumps. These variables may explain the characteristics of muscle activation (the internal structure of the movement) and ground reaction force (the external-kinetic structure of the movement). However, for various technical reasons, it was not possible to register all the specified jumps in the protocol. Moreover, the distribution normalities, estimated by the Kolmogorov-Smirnov test, differed between variables. Therefore, to compare the data, the pair-wise nonparametric Wilcoxon Signed-Ranks Test was applied. The CMJ showed the highest level of vertical impulse, velocity, and displacement followed by the TS, PS, and HS. In the take-off phase of acrobatic jumps with rotation the average muscle activation levels of the biceps femoris were significantly higher and of the rectus femoris significantly lower than in the countermovement jump.

Key words

  • Smart-E measuring system
  • gymnastics
  • movement structure
  • movement analysis
Open Access

Influence of Attentional Manipulation on Jumping Performance: A Systematic Review and Meta-Analysis

Published Online: 31 Oct 2020
Page range: 65 - 75

Abstract

Abstract

Enhancing jumping ability can lead to substantial benefits in sports performance and physical activity. Previous studies indicate that directing an individual’s attention externally before the jump is an effective way to improve jumping performance, especially when the standing long jump (SLJ) and vertical jumps (VJs) are performed. To scrutinize reported findings, we systematically reviewed studies that compared the effects of attentional manipulations on jumping performance in adults. Four electronic databases (MEDLINE, Scopus, SPORTSDiscus, and Web of Science) were searched for original research publications. A priori defined inclusion criteria were: (a) participants were healthy adults with a mean age > 18 years, (b) an external (EF) or an internal focus (IF) of attention instruction was used, (c) the study compared an external focus intervention with an internal focus intervention or an external focus with a control (no attentional; CON) intervention or an internal focus intervention with a control intervention, (d) jumping performance was tested, and (e) an immediate effect of focus of attention intervention was evaluated. Of the 380 papers identified, 14 studies were used in 3 part meta-analyses (EF vs. IF, EF vs. CON, and IF vs. CON) that involved 24 comparisons in total. The findings of this analysis revealed that the EF condition displayed superior jumping performance relatively to the IF (p < 0.05) and CON (p < 0.05) conditions. There were no significant (p > 0.05) differences between the IF and CON conditions. These findings suggest that EF instructions should be incorporated into testing procedures when jumping performance is assessed.

Key words

  • jump testing
  • external focus of attention
  • internal focus of attention
  • standing long jump
  • vertical jump
  • instructions

Section II – Exercise Physiology & Sports Medicine

Open Access

Predicting the 2000‐m Rowing Ergometer Performance from Anthropometric, Maximal Oxygen Uptake and 60‐s Mean Power Variables in National Level Young Rowers

Published Online: 31 Oct 2020
Page range: 77 - 83

Abstract

Abstract

Many studies reported various relationships between 2000-m rowing performance and anthropometric as well as metabolic variables, however, little is known about 60-s mean power in elite youth athletes. The aim of this study was to develop different regression models to predict 2000-m rowing indoor performance time (t2000) using anthropometric variables, maximal oxygen uptake (VO2max) and mean power established during a 60-s all-out test (W60) in national elite youth rowers. Fifteen youth male Italian rowers (age: 15.7 ± 2.0 years; body height: 176.0 ± 8.0 cm; body mass: 71.2 ± 10.0 kg) performed an incremental maximal test, a 60-s all-out test and a 2000-m race simulation using a Concept2 rowing ergometer to assess VO2max, W60 and t2000, respectively. The relationships of all variables with t2000 were investigated through Pearson’s correlation. Multiple regression analyses were used to verify the best prediction model of 2000-m indoor rowing performance. The reliability of these models was expressed by R2 and the standard error of estimate. The results showed that t2000 was significantly correlated with all the examined variables, except for VO2max/body mass and age, and exhibited the significantly highest relationship with W60 (r = -0.943). The combination of anthropometric, VO2max and W60 variables was found to be the most reliable equation to predict t2000 (R2 = 0.94, SEE = 6.4). W60 measure should be considered when monitoring the rower’s capability to perform high-intensity phases, important during the race’s fast start and end. Not requiring expensive equipment and long duration, a 60-s all-out test could be considered a valuable tool for predicting 2000-m performance of elite youth rowers.

Key words

  • elite youth athletes
  • mean power
  • indoor rowing
  • anthropometric variables
  • VO
  • rowing performance
Open Access

Acute Effect of Sodium Bicarbonate Supplementation on Symptoms of Gastrointestinal Discomfort, Acid‐Base Balance, and Performance of Jiu‐Jitsu Athletes

Published Online: 31 Oct 2020
Page range: 85 - 93

Abstract

Abstract

The purpose of the present study was to verify the acute effect of sodium bicarbonate supplementation on symptoms of gastrointestinal discomfort, acid-base balance and intermittent isometric handgrip test performance in Jiu-Jitsu athletes. Ten male (22.2 ± 3.9 years; 174 ± 0.07 cm; 74.5 ± 8.9 kg) jiu-jitsu athletes participated in this counterbalanced double-blind crossover study. Two protocols, a) supplementation with 0.3 g.kg-1 of body weight of sodium bicarbonate, and b) supplementation with 0.045 g.kg-1 of body weight of placebo substance, were employed. Gastrointestinal tolerability was assessed by the questionnaire. Blood samples were collected at three time points (baseline, pre-ISO, and post-ISO) to determine the responses of potential hydrogenionic (pH), bicarbonate (HCO3-), base excess (EB) and lactate concentrations. The maximum voluntary contraction test and the intermittent isometric contraction test were also performed. As a result, none of the athletes reported significant gastrointestinal discomfort (p > 0.05). HCO3-, pH, and EB at the pre-ISO and post-ISO moments were significantly higher for the sodium bicarbonate protocol. Lactate concentrations were significantly higher for both post-ISO protocols (p = 0.000). There was no significant difference in the performance of the maximum voluntary contraction test and the intermittent isometric contraction test (p > 0.05). Thus, we conclude that sodium bicarbonate supplementation does not generate adverse responses resulting in gastrointestinal discomfort, and does not benefit performance yet promotes a state of metabolic alkalosis.

Key words

  • NaHCO
  • metabolic alkalosis
  • martial arts
  • handgrip exercise
  • intermittent exercise
Open Access

Acute Physiological Responses to Ultra Short Race‐Pace Training in Competitive Swimmers

Published Online: 31 Oct 2020
Page range: 95 - 102

Abstract

Abstract

Ultra Short Race Pace training (USRPT) is an emerging training modality devised in 2011 to deviate from high-volume swimming training that is typically prescribed. USRPT aims to replicate the exact demands of racing, through its unique prescription of race-pace velocity sets with short rest intervals. It has been surmised, with little physiological evidence, that USRPT provides swimmers with the best opportunity to optimize the conditioning, technique, and psychology aspects of racing at the most specific velocity of the relevant event, with low blood lactate concentration. The aim of this study was to examine acute physiological responses of USRPT. Fourteen swimmers were recruited to perform a USRPT set: 20 x 25 m freestyle with a 35-s rest interval. Swimmers were required to maintain the velocity of their 100 m personal best time for each sprint. Sprint performance, blood lactate, heart rate and the RPE were measured. Blood lactate was taken before, during (after every 4 sprints) and 3 minutes after the USRPT protocol. Heart rate monitors were used to profile the heart rate. Athletes reported the RPE before- and after completion of the USRPT set. Sprint times increased by 3.3-10.8% when compared to the first sprint (p < 0.01). There was high blood lactate concentration (13.6 ± 3.1mmol/l), a significant change in the RPE from 8 ± 1.6 to 18 ± 1.6 (p < 0.01) and a substantially high heart rate profile with an average HRmax of 188 ± 9 BPM. The results show the maximal intensity nature of USRPT and portray it as an anaerobic style of training.

Key words

  • swimming
  • high-intensity
  • heart-rate
  • blood-lactate
  • sprinting
  • and performance
Open Access

Shoulder Muscle Imbalance as a Risk for Shoulder Injury in Elite Adolescent Swimmers: A Prospective Study

Published Online: 31 Oct 2020
Page range: 103 - 113

Abstract

Abstract

Muscle strength imbalances between the internal and external rotators of the shoulder are frequent in swimmers, but their role in shoulder injury remains unknown. We aimed to evaluate the association of shoulder rotator strength and injury in elite adolescent swimmers. Eighteen adolescent swimmers performed preseason isokinetic tests of the internal and external rotator muscles in concentric (con) and eccentric (ecc) modes. Conventional (conER:conIR and eccER:eccIR) and functional ratios (eccER:conIR and eccIR:conER) were calculated. Thirteen swimmers completed a weekly questionnaire about swimming habits and shoulder injuries throughout the season. Preseason testing showed a significant negative association between the functional eccER:conIR ratio and years of practice (p < 0.05). Over the season, 46% of athletes experienced at least one shoulder injury. At the end of the season, peak torques increased for both internal and external rotator muscles strength, but only concentrically, resulting in a decrease in the eccER:conIR functional ratio (p < 0.05). The receiver operating characteristic curve analysis highlighted good predictive power for the preseason functional eccER:conIR ratio, as values below 0.68 were associated with a 4.5-fold (95% CI 1.33-15.28, p < 0.05) increased risk of shoulder injuries during the season.

Key words

  • swimming
  • sports injury prevention
  • isokinetic testing
  • strength imbalance
Open Access

The Relationship Between Repeated‐Sprint Ability, Aerobic Capacity, and Oxygen Uptake Recovery Kinetics in Female Soccer Athletes

Published Online: 31 Oct 2020
Page range: 115 - 126

Abstract

Abstract

This study investigated the relationship between repeated-sprint ability, aerobic capacity, and oxygen uptake kinetics during the transition between exercise and recovery (off-transient) in female athletes of an intermittent sport modality. Eighteen professional soccer players completed three tests: 1) a maximal incremental exercise test; 2) a constant speed time-to-exhaustion test; and 3) a repeated-sprint ability test consisting of six 40-m sprints with 20 s of passive recovery in-between. Correlations between time-to-exhaustion, repeated-sprint ability, and oxygen uptake kinetics were calculated afterwards. The level of significance was set at p < 0.05. A performance decrement during repeated-sprint ability was found to be related to: 1) time-to-exhaustion (e.g., exercise tolerance; r = -0.773, p < 0.001); 2) oxygen uptake recovery time (r = 0.601, p = 0.008); and 3) oxygen uptake mean response time of recovery (r = 0.722, p < 0.001). Moreover, the best sprint time (r = -0.601, p = 0.008) and the mean sprint time (r = -0.608, p = 0.007) were found to be related to maximal oxygen uptake. Collectively, these results reinforce the relation between oxygen uptake kinetics and the ability to maintain sprint performance in female athletes. These results may contribute to coaches and training staff of female soccer teams to focus on training and improve their athletes’ aerobic capacity and recovery capacity to improve intermittent exercise performance.

Key words

  • oxygen uptake kinetics
  • sprinting ability
  • intermittent modality
  • women soccer
  • women athletes
Open Access

Influence of Inspiratory Muscle Training of Various Intensities on The Physical Performance of Long‐Distance Runners

Published Online: 31 Oct 2020
Page range: 127 - 137

Abstract

Abstract

The aim of this study was to assess the efficacy of inspiratory muscle training (IMT) at different intensities on the pulmonary function and physiological adaptations of long-distance runners undergoing sports training. This study involved 25 long-distance runners. The subjects were randomly divided into three groups depending on the type of IMT applied: POWERbreathe device (group 1), Threshold IMT device (group 2), and a control group. The following lung variables were evaluated: vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF). Respiratory muscle strength was assessed by maximum inspiratory pressure (PImax) and maximum expiratory pressure (PEmax). Spiroergometric measures included: heart rate (HR), oxygen uptake (VO2max), carbon dioxide production (VCO2max), maximum ventilation (VE) and respiratory exchange rate (RER), which were measured breath by breath using a gas analyser (VYNTUS CPX). Group 1, which used the POWERbreathe device, showed significant increases in all assessed physiological and physical performance variables. In group 2, which used the Threshold device, only VO2max, VE and tRER ventilation were significantly increased to a similar level as that observed in group 1. In the control group, we only observed a significant reduction in saturation. The use of IMT with a higher intensity resulted in significant improvements in all tested variables of lung ventilation and respiratory muscle strength. Also, after training, lactate accumulation was significantly decreased. Physiological characteristics (VO2max/kg) and muscle respiratory strength variables were significantly improved in the group that used the POWERbreathe device after 8 weeks of training.

Key words

  • inspiratory muscle training
  • runners
  • pulmonary function
  • physiological adaptations
Open Access

The Immediate Effects of Self‐Myofacial Release on Flexibility, Jump Performance and Dynamic Balance Ability

Published Online: 31 Oct 2020
Page range: 139 - 148

Abstract

Abstract

Self-myofascial release (SMR) is a popular method to potentially increase the compliance and extensibility of the fascia and reduce muscle stiffness. The purpose of this study was to examine the acute effects of posterior muscle chain SMR on flexibility, vertical jump performance and balance ability. Eighteen young participants volunteered to take part in this crossover design study. They performed two self-massage sessions in randomized order separated by at least one week. One session consisted of posterior muscle chain SMR whereas the other one was performed on the upper limbs as a control intervention (CON). Flexibility was measured with the Toe Touch Test (TTT), Weight-Bearing Lunge Test (WBLT), and Straight Leg Raise Test (SLR). Jump performance was evaluated during a squat jump, a counter movement jump and a stiffness jump. Dynamic balance ability was assessed through the Star Excursion Balance Test. All these variables were measured before and after each intervention. A significant increase in flexibility (+3.5 ± 1.8 cm, +1.6 ± 1.0°, and +7.7 ± 4.0° for the TTT, WLBT, and SLR, respectively, p < 0.003) and balance performance (4.8 ± 3.9 cm, p < 0.003) was observed following SMR intervention compared to CON. Conversely, jumping performance was unchanged in both groups. SMR improves joint flexibility and dynamic balance ability.

Key words

  • roller massage
  • foam rolling
  • range of motion
  • jumping performance
  • balance ability

Section III – Sports Training

Open Access

The Relative Age Effect at the Ice Hockey World Championships (IHWC) in the years 2015–2017

Published Online: 31 Oct 2020
Page range: 150 - 159

Abstract

Abstract

The relative age effect (RAE) theory is based on the premise that athletes born in the first months of the calendar year have a significant probability of a higher level of physiological, morphological and psychological abilities compared to later-born athletes. The aim of our study was to verify the influence of the RAE on adult ice hockey players, specifically Ice Hockey World Championships’ (IHWC) participants in the years 2015−2017 (n = 1,200). Based on the chi-squared (χ2) analysis, the influence of the RAE during the 2015−2017 period could not be rejected for all observed players (χ2 = 54.6, p < 0.01, w = 0.21) or for all the players for particular years (2015, 2016, and 2017; p < 0.01). During the monitored period (2015−2017), the RAE could not be rejected for any player’s position (forward, defender, or goaltender). Based on the effect size analysis (Cohen’s w), the strongest RAE was observed among goaltenders (w = 0.31), then forwards (w = 0.24) and finally defenders (w = 0.15). The assessment of player’s positions in particular years showed statistical significance for goaltenders only in 2015 (χ2 = 11.3, p < 0.05). With regard to forwards, significance was confirmed for 2015 (χ2 = 8.5, p < 0.05), 2016 (χ2 = 15.2, p < 0.01) and 2017 (χ2 = 14.3, p < 0.01). Therefore, the presence of the RAE could not be rejected for all these cases. The results of the research show that members of national teams in the years 2015−2017 were players who were chronologically older, which is consistent with the results of other authors addressing the RAE.

Key words

  • athletic talent
  • birthdate
  • national teams
  • player’s position
Open Access

Relationships Between Measures of Functional and Isometric Lower Body Strength, Aerobic Capacity, Anaerobic Power, Sprint and Countermovement Jump Performance in Professional Soccer Players

Published Online: 31 Oct 2020
Page range: 161 - 175

Abstract

Abstract

The purpose of this study was to assess a wide range of physiological and performance variables and investigate whether and to what extent these variables are associated with each other in soccer. Twenty-five male soccer players (25.1 ± 4.56 years; body mass, 75.2 ± 5.92 kg; body height, 180.6 ± 5.45 cm) performed: 5- and 30-m sprints (T5m and T30m, respectively), 1-repetition-maximum (1RM) half squat, maximal voluntary isometric contraction (MVIC) of the knee extensors, countermovement jump (CMJ) to obtain vertical jump height (CMJheight) and power output (CMJpower), the 10-s Wingate Anaerobic Test (WAnT) to obtain peak power (Pmax), and the 20-m multi-stage shuttle run test (MST) to evaluate aerobic capacity. 1RM, MVIC, and Pmax were normalized to body mass. Large negative correlations were found between sprint times and 1RM half back squat/BM (r = -0.510 to -0.570, r2 = 0.260–0.325, both p < 0.01) and Pmax/BM (r = -0.501, r2 = 0.251, p < 0.01). T30m most strongly and negatively correlated with CMJheight (r = -0.744, r2 = 0.554, p < 0.001). WAnT-determined Pmax showed a very large correlation between absolute Pmax and knee-extensor MVIC (r = 0.827, r2 = 0.684, p < 0.001) and large correlations between absolute Pmax and 1RM half squat (r = 0.674, r2 = 0.454, p < 0.001) and CMJpower (r = 0.579, r2 = 0.335, p < 0.01). We also identified a large inverse relationship between CMJheight and T30m (r = -0.744, r2 = 0.554, p < 0.001) and large positive correlation between CMJheight and MVIC/BM (r = 0.702, p < 0.001). The results demonstrate that elite soccer players with greater lower body strength (quantified by the MVIC of the knee extensor and the 1RM half squat) show better sprint and CMJ performance, suggesting the incorporation of soccer-specific resistance training to develop lower body musculature and therefore maximize sprinting ability. The higher correlation coefficients found between T30m and the physiological and athletic measures compared with T5m promote the use of this sprint distance when assessing performance. The use of relative measures (normalized to body mass) is advisable when comparing strength variables with sprint and CMJ performance or anaerobic power. Considering the correlations of WAnT-determined Pmax versus CMJpower, coaches should administer tests that assess jumping and linear sprint performance rather than the cycling-specific WAnT.

Key words

  • static and dynamic muscular strength
  • sprinting ability
  • acceleration
  • physiological response
  • endurance shuttle run
  • competitive soccer
Open Access

Statistical Comparison of Singles Badminton Matches at the London 2012 and Rio De Janeiro 2016 Olympic Games

Published Online: 31 Oct 2020
Page range: 177 - 184

Abstract

Abstract

The aim of this study was to analyse statistical differences in men’s and women’s singles badminton competitions at the London and Rio Olympic Games. Forty-five matches (128 sets in total) played at the 2012 and 2016 Olympics in badminton were analysed. Variables related to the match (6) and each set (13) were determined. The results show the longest rally in sets 1 and 3, the biggest come back to win the game in set 2, and that the duration of set 3 for men was longer in Rio than in London. All of the women’s sets had longer duration, and the rally length and the number of strokes per rally was also longer in Rio versus London. In conclusion, the timing factors of badminton singles were dissimilar in London 2012 and Rio 2016 for both men and women. This information may help players and coaches manage different workout types or, more specifically, competition schedules that are adapted to suit modern badminton’s characteristics.

Key words

  • racket sport
  • notational analysis
  • elite performance
Open Access

The Explanatory Capacity of Talent Identification Tests for Performance in Triathlon Competitions: A Longitudinal Analysis

Published Online: 31 Oct 2020
Page range: 185 - 193

Abstract

Abstract

The aim of this study was to determine the explanatory capacity of the Spanish Triathlon Federation’s talent identification tests in relation to performance in competition in subsequent years. We used an exploratory longitudinal study design to establish the relationship between talent identification tests completed by 247 triathletes (97 women and 150 men) aged from 14 to 19 years and the results they obtained over the years in competition. The battery of tests included freestyle swimming (100 and 1000 m) and running (400 and 1000 m). The results indicate that the explanatory capacity of these tests for split places in competition in the corresponding discipline was highest in the 1000-m swimming test, with a value of 0.34 for the adjusted coefficient of determination (R2a) (p ≤ 0.001), followed by the 1000-m running and 100-m swimming tests, where the highest R2a values were 0.26 and 0.19, respectively. No significant model was found for the 400-m running test. It was concluded that the explanatory capacity of the tests analysed for predicting performance in the discipline in competition was low. However, it was higher for the swimming and running tests of longer distance.

Key words

  • talent identification
  • sports performance
  • triathlon performance
  • endurance sports
  • youth sports
  • exercise tests
Open Access

Match and Training High Intensity Activity-Demands Profile during a Competitive Mesocycle in Youth Elite Soccer Players

Published Online: 31 Oct 2020
Page range: 195 - 205

Abstract

Abstract

The monitoring of the high intensity activity-demands profile during official matches (OMs) and training sessions (TSs) provides a deeper understanding of the relationship between training and competition loads as well as players’ fitness characteristics. The aims of this study were to: 1) describe the training and match high intensity activity-demands profile in U-19 soccer players; 2) compare the profile depending on the type of session (OM or TS) throughout match-weeks; and 3) differentiate between profiles depending on the match location (home or away). Twenty-five U-19 Spanish soccer players were monitored during TSs and OMs for a one-month competitive period using a WIMU PROTM wearable inertial device. The variables of the study were: high speed running distance (HSRD), total sprints (SPs), maximum speed (MS) and player load (PL). OMs required higher demands than TSs in HSRD (460.99 ± 206.18 vs. 315.45 ± 180.12 m; p < 0.01; d = 0.75), SPs (10.86 ± 6.64 vs. 7.23 ± 4.82; p < 0.01; d = 0.69), MS (29.99 ± 2.54 vs. 28.50 ± 2.4 km/h; p < 0.01; d = 0.59) and PL (103.08 ± 24.15 vs. 83.18 ± 17.96 a.u.; p < 0.01; d = 0.94). The interaction between the type of session and mean week’s demands presented differences with medium effect size in MS (p < 0.01; ωp2 = 0.06) and small effect size in HSRD (p = 0.04; ωp2 = 0.03), and SP (p = 0.05; ωp2 = 0.03), but there were no differences in PL (p = 0.18; ωp2 = 0). Finally, no differences were found in the match location comparison (p > 0.33; d = 0.22–0.33). Therefore, the profiles presented could be useful for future scientific purposes and serve as valid information for coaches trying to optimize performance.

Key words

  • workload
  • competition
  • team sports
  • inertial devices
  • performance
Open Access

A Systematic Review of the Batting Backlift Technique in Cricket

Published Online: 31 Oct 2020
Page range: 207 - 223

Abstract

Abstract

There has been an extensive amount of research into the batting elements of cricket. However, there is limited research specifically on the batting backlift technique (BBT). Therefore, this review aims to provide an understanding and consensus of the BBT in cricket at varied skilled levels. A PRISMA flow chart revealed 38 studies that were reviewed (both coaching and scientific literature), which reported on the backlift in cricket. The databases searched were PubMed, Google Scholar, the Cochrane Library and Sabinet. This review shows that the lateral batting backlift technique (LBBT) is a likely contributing factor to successful batsmanship at all levels of cricket ability (junior, adolescent, semi-professional, professional, international and former elite/successful cricketers). It was also found that coaching a LBBT to young batsmen may be challenging to teach, and therefore, further coaching models should be developed to assist cricket coaches. As much as a LBBT may be a contributing factor for success, there is still a need to answer a number of questions through further in-depth biomechanical investigations and through interventions that are more meticulous. A way forward for further research in this area of cricket batting is documented at the end of the review.

Key words

  • biomechanics
  • performance analysis
  • coaching
  • batters
  • cricketers
Open Access

Tactical Behaviour of Youth Soccer Players: Differences Depending on Task Constraint Modification, Age and Skill Level

Published Online: 31 Oct 2020
Page range: 225 - 238

Abstract

Abstract

This study aimed to investigate: i) how Small-Sided and Conditioned Games based on different representation and exaggeration modification strategies, from the Teaching Games for Understanding pedagogical principles, affected team performance and exploratory behaviour; and ii) how teams and players of different ages and skill levels were affected by the use of these different modification strategies. In total, forty-eight youth male soccer players participated in the study (U15, n = 24 mean age = 13.06 ± 1.53 years; U17, n = 24 mean age = 16.89 ± 0.11 years). In both categories, players were organized into three groups according to their tactical efficiency level (Group 01 = High Skilled Players (HSP), Group 02 = Intermediate Skilled Players (ISP), and Group 03 = Low Skilled Players (LSP)). The HSP and LSP groups performed two types of Gk+4vs4+Gk Small-Sided and Conditioned Games (SSCGs) based on different representation and exaggeration modification strategies. The first type of SSCGs was modified by structural constraints (Structural SSCG) and the second type was modified by rule manipulation (Manipulation SSCG). Team performance and exploratory behaviour were analysed through the Offensive Sequences Characterization System and Lag Sequential Analysis, respectively. SSCG modification strategies affected differently tactical performance and exploratory behaviour of teams composed of players of different skill levels. It was found that SSCG modification strategy through rule manipulation provided players and teams with a higher level of difficulty, compromising their performance and inhibiting exploratory behaviour. This information is crucial to practitioners wishing to apply more appropriate pedagogical strategies to improve a specific tactical problem using a player-centred and game-based approach.

Key words

  • nonlinear pedagogy
  • pedagogical principles
  • tactical skills
  • performance level
  • complexity
Open Access

Muscle Activity Asymmetry of the Lower Limbs During Sprinting in Elite Soccer Players

Published Online: 31 Oct 2020
Page range: 239 - 245

Abstract

Abstract

The analysis of movement patterns through EMG activity provides the opportunity to identify the muscle groups most involved in a particular exercise, and to determine the scope of inter-limb deficiencies. The aim of the present study was to investigate the effects of a side-to-side muscle activity asymmetry between the left and the right lower limb during sprinting in soccer players. Sixteen professional soccer players took part in the study. Their age, body mass and body height equaled 23.7 ± 7.6 years, 81.2 ± 10.8 kg and 179.3 ± 12.2 cm, respectively. The sprint test consisted of two maximal sprints over 30 m with a 5-min rest interval between each sprint. EMG was recorded bilaterally from the quadriceps, hamstrings and gluteal muscles. Regression analysis revealed a significant effect of a side-to-side average muscle activity asymmetry between the left and right hamstring (LH/RH) muscles during the speed tests at 5 m (p = 0.044), and 30 m (p = 0.045), as well as the left and right glutes (LG/RG) at 5 m (p = 0.044) and 30 m (p = 0.043). Our results indicate that hamstring and glute muscles should be selectively and additionally activated during resistance training in soccer players to prevent injuries and improve sprint performance.

Key words

  • soccer
  • EMG
  • sprinting
  • movement pattern
Open Access

Comparisons of Motor Actions and Biomechanical Assessments of Judo Techniques Between Female Weight Categories

Published Online: 31 Oct 2020
Page range: 247 - 255

Abstract

Abstract

This study aimed to perform motor action and biomechanical analysis of techniques in female judo athletes separated by weight categories of 638 female bouts (103 extra lightweight <48 kg, 140 half lightweight 48>52 kg, 65 lightweight 52>57 kg, 73 half middleweight 57>63 kg, 77 middleweight 63>70 kg, 80 half heavyweight 70>78 kg and 60 heavyweight >78 kg). All bouts were analyzed following the phases of approach, gripping, defensive action, attack, also biomechanical analysis of techniques and groundwork was performed (p ≤ .05). Results indicated that lightweight athletes presented lower attempts to grip, right collar grip and left collar grip frequencies than other categories. Extra lightweight judokas presented lower right back grip and left back and sleeve grip frequencies as well as lower occurrence of techniques with arm and leg lever scored than half lightweight athletes, while half lightweight athletes demonstrated higher frequency of techniques with waist lever variable scored than lightweight ones. These findings should be considered for training prescription.

Key words

  • time and motion analysis
  • biomechanical analysis
  • task performance and analysis
  • martial arts
  • motor control
  • training
Open Access

Differences in External Load Variables Between Playing Positions in Elite Basketball Match-Play

Published Online: 31 Oct 2020
Page range: 257 - 266

Abstract

Abstract

The purpose of this study was to describe the specific demands and structure of interrelationships of external load variables in order to generate a position-related time motion profile in elite basketball. Seventeen professional players from three different playing positions (6 guards, 4 forwards, and 7 centers) were analyzed in five friendly games. Player load per minute (PLmin) was used as an indicator of intensity to compare positions. Furthermore, high and total external variables of jumping (hJUMP and tJUMP), acceleration (hACC and tACC), deceleration (hDEC and tDEC) and change of direction (hCOD and tCOD), respectively, were used for the principal component analysis (PCA). The Kaiser criterion (eigenvalue > 1) was applied, and the Varimax rotation mode was used to extract multiple principal components. PCA showed that all positions had three or four principal components, but the configuration of each factor was different: tCOD, hCOD, hDEC and hJUMP for guards, hCOD, tCOD, tACC and hDEC for forwards, and tJUMP, hJUMP, hDEC and tACC for centers were specifically demanded in match-play. For guards and forwards, a significant correlation was found between COD variables, while for centers tCOD and PLmin had the strongest correlation. When monitoring the external load via tri-axial accelerometers in basketball match-play, each playing position showed specific physical demands. Therefore, these variables must be prioritized in load monitoring programs.

Key words

  • playing position
  • team sport
  • time motion
  • basketball
  • PCA
  • game load
Open Access

Effects of Ischemic Preconditioning as a Warm-Up on Leg Press and Bench Press Performance

Published Online: 31 Oct 2020
Page range: 267 - 277

Abstract

Abstract

Ischemic preconditioning (IPC) has been used to increase performance in sports. The aim of this study was to compare the acute effects of IPC with different warm-up methods on the number of repetitions and total volume in resistance exercise (RE). Sixteen healthy men recreationally trained in RE participated in this study. After the anthropometric evaluation and familiarization, a one-repetition maximum (1RM) test and retest were performed in the bench press (BP) and in the leg press 45° (LP) exercise. After these tests, participants were randomly assigned to one of the five protocols: a) IPC; b) SHAM; c) a specific warm-up (SW); d) aerobic exercise (AE), and e) active stretching (AS) prior to performing 3 sets at 80% 1RM until concentric failure. The number of repetitions was higher following IPC compared to the SW following three sets both for the BP and LP. Similarly, the number of repetitions for IPC was higher in comparison to SHAM following three sets for the LP. The number of repetitions was higher following IPC compared to AE following 1st and 2nd sets for the LP and following the 2nd set for the BP. Finally, the number of repetitions was higher following IPC compared to AS following 1st and 2nd sets for the LP. The total volume was higher following IPC compared to SHAM, SW, AE, and AS for both the BP and LP. The IPC protocol increased the number of maximum repetitions and the total volume when compared to the other tested methods, thus indicating a better utilization during the pre-work warm-up. These results indicate positive associative responses to IPC with performance maintenance, which is of importance for both athletes and coaches.

Key words

  • ischemic preconditioning
  • resistance exercise
  • warm-up
  • performance
  • ischaemia

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