Introduction. Studies have revealed that the anabolic effect of irisin on bone is mediated by an increase in alkaline phosphatase. However, few studies have investigated the interactive effect of irisin on alkaline phosphatase after exercise training. Therefore, the present study aimed to compare the impact of endurance and resistance training protocols on serum irisin concentration and total alkaline phosphatase activity in sedentary obese women.
Material and methods. Forty-five sedentary obese women (age: 48.96 ± 5.2 years, body mass index 32.24 ± 3.76 kg/m2) were randomly assigned to control, endurance, and resistance groups. Endurance (45 to 75 minutes at an intensity corresponding to 50 to 80% of heart rate reserve) and resistance exercise training (3 sets, 10-15 repetitions at an intensity corresponding to 50 to 65% of one-repetition maximum) were conducted for 8 weeks, 3 days per week. Maximal oxygen consumption (VO2max) was estimated using the modified Bruce protocol treadmill test. Fasting blood samples were taken before the first and 48-hr after the last exercise training sessions. The serum concentrations of irisin and total alkaline phosphatase activity were measured using the sandwich ELISA method and photo-metric method, respectively.
Results. Both endurance and resistance exercise training protocols caused a significant reduction in BMI and BFP of obese women. In contrast, VO2max significantly increased after both exercise training protocols. However, neither endurance nor resistance training protocols had a significant impact on the serum concentrations of irisin and total alkaline phosphatase activity. No significant inter-group differences were observed between the subjects’ BMI, BFP, VO2max, total alkaline phosphatase, and irisin at the end of protocols.
Conclusions. The finding of the current study revealed that neither of the training protocols had a significant impact on bone anabolic parameters. However, performing these types of exercise is suggested for weight management in obese women.
