The cardiovascular promotion of college taekwondo based on fractional differential equation

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Introduction
Fractional partial differential equations are derived from traditional partial differential equations.The fractional partial differential equation is obtained by replacing the time (space) derivative term in the traditional partial differential equation with fractional derivative.For nearly three centuries, fractional calculus has only been used in the pure theoretical field of mathematicians.However, in recent decades, many researchers began to use fractional partial differential equations to study many systems in the scientific and engineering fields.From the definition of fractional derivative, the fractional derivative of a function at tk depends on the value of the function at all previous times t<tr, which makes the fractional partial differential equation more advantageous than the integral equation model in studying some memory processes, genetic properties and heterogeneous materials, for example, the electrical properties of materials are described as electromagnetic wave concavity, boundary layer effect in conveying pipes, and control theory in dynamic systems, viscoelastic material feedback amplifier, electrode electrolyte polarization phenomenon, conductance in biological system, fractal dynamics, chaos synchronization, abnormal diffusion process of ions in nerve cells, etc. Taekwondo is a kind of sports which is mainly about kicking and using both hands and feet, the competition time is 3 min for 3 rounds, and the rest time is 1 min.At present, the "World Taekwondo Federation" has 142 member states, becoming one of the largest sports organizations in the world.China has officially launched taekwondo for only two or three years, it has held two national taekwondo championships and two national championships, and taekwondo is growing rapidly in China.However, through consulting relevant data and investigation, it is found that there are not many researches on cardiovascular function of taekwondo athletes at home and abroad, and the indicators are single, especially in China [1].As shown in Figure 1:

Literature Review
With the rapid economic growth, the social arrival of university taekwondo and the change of social structure, the spectrum of diseases has changed, medical costs have increased rapidly, and medical and health services are facing great challenges.The recently released China Cardiovascular Disease Report 2018 outlines that the prevalence and mortality of cardiovascular diseases in China are on the rise, it is estimated that the number of cardiovascular patients at this stage is about 290 million, among them, 245 million were hypertension, 11 million were coronary atherosclerotic heart disease (coronary heart disease), and 4.5 million were heart failure (heart failure); The death rate of cardiovascular disease ranks first, higher than that of tumor and other diseases, and has become a major public health problem in the 21st century.Many previous studies have shown that cardiac rehabilitation exercise can benefit patients with cardiovascular diseases in a dose dependent manner, significantly improving the quality of life of patients and reducing the risk of death.As a form of expression of traditional Chinese martial arts, college taekwondo is also one of the low and medium intensity aerobic sports, which is safe and low-cost, at present, most universities tend to protect human body by regular taekwondo [2].

Origin and characteristics of taekwondo
Taekwondo originated from Chenjiagou, Zhaobao Town, Wen County, Jiaozuo City, China, it is a cultural form with Chinese traditional ethnic characteristics.In the middle of the 17th century, on the basis of family handed boxing, Chen Wangting absorbed the strengths of many martial arts and created a new set of boxing with yin and yang opening and closing, hardness and softness combining, and internal and external cultivation, it was named Taekwondo, which was passed down from generation to generation, and derived many schools such as Yang style, Wu style, Sun style, and He style.At present, Chen's Taiji Twenty four Movements are widely spread among the people, which combines boxing, guiding and breathing, during the drill, it is required to guide the action with ideas, pay attention to the active relaxation of breathing and neuromuscular, and closely combine consciousness, breathing and action to achieve the purpose of strengthening the body and prolonging life.Taekwondo is called "meditation in exercise", which involves not only physical exercise, but also mental concentration and breath control.It is widely used in cardio pulmonary diseases, bone joint muscle related diseases, sleep disorders, psychology, fall prevention, Parkinson's disease and other fields [3].

Influence of taekwondo on risk factors of common chronic cardiovascular diseases
It is well known that risk factors related to chronic cardiovascular disease include hypertension, hyperglycemia, hyperlipidemia, overweight or obesity, smoking, etc, this series of risk factors promote the occurrence and progress of cardiovascular disease through synergistic interaction, which doubles the risk of disability and death, therefore, effective management of risk factors of chronic cardiovascular disease can curb the progress of cardiovascular disease at the source.Blood pressure variability (BPV) is a powerful indicator that is different from blood pressure level and can independently reflect blood vessel activity.It is an important indicator to measure the degree of blood pressure fluctuation, evaluate the condition and prognosis of hypertension.The larger the BPV, the more obvious the target organ damage.Similarly, the pathogenesis of hypertension is closely related to abnormal sympathetic regulation, renin angiotensin activation, release of vascular endothelial factors (such as nitric oxide, endothelin, etc.), oxidative stress, etc. Research shows that taekwondo exercise prescription combined with antihypertensive drugs can improve blood pressure variability in patients with hypertension, effectively prevent damage to relevant target organs, reduce plasma endothelin-1 concentration, increase serum nitric oxide (NO) concentration, and improve endothelial function, the sleep state and physiological state of patients with hypertension have also been improved, on the basis of conventional treatment, it is proposed to promote taekwondo as an important complementary means of rehabilitation.A study on young and middle-aged hypertensive patients at work found that systolic blood pressure, heart rate, triacylglycerol, total cholesterol, low-density lipoprotein cholesterol, body mass index, blood glucose, diastolic blood pressure, etc. were significantly reduced after one month of taekwondo exercise (all P<0.05), the pulse pressure did not change significantly.Similar effects were still observed after 3 months of exercise, and it was considered that taekwondo exercise could be a good exercise choice for young and middle-aged patients with grade I hypertension.However, some scholars' meta-analysis of primary prevention of cardiovascular disease shows that, there is still a great heterogeneity in the conclusions about the impact of taekwondo exercise on blood pressure among the studies.In addition, oxidative stress is closely related to the pathogenesis of hypertension, and the reduction of nitric oxide (NO) bioavailability is one of its pathogenesis, Taekwondo, as a medium intensity aerobic exercise, can significantly reduce miR-145 in blood pressure by promoting oxidative stress and endothelial function, and seems to participate in it through its upstream signal to reverse regulate AKT signal.Research shows that exercise can remodel hypertensive arterioles and induce vascular smooth muscle cells to maintain the contractile phenotype, while taekwondo exercise is related to hypertension.Whether epigenetic regulation can play a similar role needs further exploration.The influence of Taekwondo on blood lipid profile has also been concerned.Mate analysis shows that taekwondo exercise has potential benefits for the overall lipid distribution of different age groups and populations.Someone studied the influence of taekwondo training on coronary heart disease risk factors in patients with dyslipidemia, and conducted taekwondo intervention in December, body composition, blood lipids, fasting blood glucose, insulin levels and inflammatory indicators were measured before and after training.It was found that blood pressure, triacylglycerol, total cholesterol, low-density lipoprotein cholesterol, blood glucose, steady-state model evaluation index and high-sensitivity Creactive protein in the taekwondo group were significantly reduced, suggesting that taekwondo exercise can significantly improve human metabolic disorders [4].

Research objects and methods
There are 8 male athletes in the Ruan Quando team of a university sports college.The average age is 20 to 25 years old, the average height is 167 cm, the average weight is 61.38 kg, and the average training period is 2.5 years.

CF-K cardiovascular function tester developed by Naixing Biomedical Engineering Research
Institute was used to test the subjects.The testing and sampling procedures are: sampling in silence; Three groups of kick handles were kicked with all strength, each group lasted for 1 im n, and the interval between groups was 1 min, and samples were taken after each group ended (i.e.intermittent kicking method); Take samples after 3 min rest; One group of kicking handle with all strength, 3 min time, sampling (3 min kicking method); Take samples after 3 min rest.Obtain 7 sampling index data [5].
The data were processed on the medical statistics software of CF-1 cardiovascular function examination instrument.24 cardiovascular function index parameters (Table 1) were used for reference in sports research.

Results and analysis
Changes and Mechanism of Heart Blood Tube Function after Taekwondo Mobilization (Table 2).
Taekwondo is a kind of strong antagonistic exercise, according to the blood lactic acid value measured after the exercise, its metabolic mode is anaerobic energy supply.The mechanism of hemodynamic changes related to the accumulation of blood lactic acid is as follows: During strenuous exercise, the sympathetic adrenal system is in an excited state, under the control of neurohumors, the heart rate (HR) and myocardial contractility (MCF) are increased according to the demand for blood and energy supply after exercise.Under the condition of a certain amount of return blood, the stroke work index (PI) and ejection fraction (EF) increased, so the cardiac output (CO) and cardiac index (CI) increased.The increase of mean arterial pressure (MAP) depends on two factors: Cardiac output and peripheral cardiac resistance (SVR).The latter, due to the need to increase cardiac output and the influence of blood lactic acid, is gradually declining during exercise.The decrease of SVR was related to the increase of capillary opening (COD), which together decreased the pressure gradient (MCG) at arterial terminals.So as to ensure that the capillary has enough increased pressure (CBP) and blood flow (BFV), so that the microcirculation has sufficient blood supply (PSI).The opening and expansion of hair vessels is to meet the needs of blood supply of muscle and other extremities, as well as the local effect of metabolites such as blood lactic acid.Extensive hyperemia and dilation of capillaries reduce arterial blood volume (ABV), thus increasing blood viscosity resistance (BVR), speeding up blood flow velocity (BFV), shortening mean circulation time (MCT), and increasing blood circulation frequency, power, flow and speed, which is manifested in the increase of BI and RPP, the results showed that cardiac work load and myocardial oxygen consumption (MVO) increased and coronary ischemic threshold (CIT) decreased.The decrease of left ventricular and arterial compliance (LVC and MAC) during exercise is just a manifestation of the tension of sympathetic adrenal system, the regulation of neurohumors actually takes part in the influence on various hemodynamic links [6][7].

Comparison of cardiovascular function parameters between two training methods for taekwondo athletes
Compare the cardiovascular function parameters of intermittent kicking and 3-min kicking after exercise (Table 3).The results showed that there was no significant statistical difference in 24 cardiovascular function parameters.It shows that the immediate effects of the two training methods are consistent [8].The level of endurance and physical strength of athletes is closely related to the level of cardiac function.One of the important reasons why the endurance level of excellent athletes is lower than that of foreign excellent sports is that the cardiac output is obviously lower than that of foreign athletes, which is also an important reason why our performance in some events is lower.Medical research shows that during the period of sudden increase in the development of young people's heart beat volume, men are 13-14 years old and women are 11-12 years old, it is necessary to protect their hearts during training to make them fully developed.In order to make the heart development of young athletes in puberty more perfect and the heart beat volume larger, it is necessary to reasonably use the heart rate with the largest heart beat volume in training.The maximum stroke volume "peak" does not appear in the extreme load of the fastest heart rate, but in the intensity of 50%~60%, this can not only make the heart get the maximum relaxation, but also make the heart get sufficient blood supply.Therefore, in the adolescent development period, especially in the sudden increase stage of cardio cerebral development, aerobic endurance training should be put at the top of the training, aerobic endurance is the basis of general endurance, and the proportion in training must be considered [9][10].

Conclusion
To sum up, based on previous research evidence, most studies tend to the view that taekwondo exercise can benefit chronic cardiovascular disease, however, most of the studies reported at home and abroad are small sample intervention trials, which are short in time and not deep enough, there is an urgent need for more multicenter and longitudinal studies on the long-term efficacy of Taijiquan exercise and the prognosis evaluation of cardiovascular disease patients, so as to provide more clinical and theoretical basis for its promotion on the community platform based on the concept of cardiac rehabilitation.

Figure 1 .
Figure 1.University Taekwondo under Fractional Differential Equation

Table 1 .
24 cardiovascular function parameters for sports research

Table 2 .
Parameters of changes in cardiovascular function of taekwondo athletes before and after exercise (X men SD)

Table 3 .
Comparison of cardiovascular function parameters of taekwondo athletes after two training methods (X men SD)