Forensic Sciences ; Hormones ; pharmacology ; physiology ; Humans ; Sports

Athletes ; Humans ; Microcirculation ; Muscles ; physiology ; Sports

Blood Chemical Analysis ; Humans ; Water Sports ; physiology

Androgen doping in power sports is undeniably rampant worldwide. There is strong evidence that androgen administration in men increases skeletal muscle mass, maximal voluntary strength and muscle power. However, we do not have good experimental evidence to support the presumption that androgen administration improves physical function or athletic performance. Androgens do not increase specific force or whole body endurance measures. The anabolic effects of testosterone on the skeletal muscle are mediated through androgen receptor signaling. Testosterone promotes myogenic differentiation of multipotent mesenchymal stem cells and inhibits their differentiation into the adipogenic lineage. Testosterone binding to androgen receptor induces a conformational change in androgen receptor protein, causing it to associate with beta-catenin and TCF-4 and activate downstream Wnt target genes thus promoting myogenic differentiation. The adverse effects of androgens among athletes and recreational bodybuilders are under reported and include acne, deleterious changes in the cardiovascular risk factors, including a marked decrease in plasma high-density lipoproteins (HDL) cholesterol level, suppression of spermatogenesis resulting in infertility, increase in liver enzymes, hepatic neoplasms, mood and behavioral disturbances, and long term suppression of the endogenous hypothalamic-pituitary-gonadal axis. Androgens are often used in combination with other drugs which may have serious adverse events of their own. In spite of effective methods for detecting androgen doping, the policies for screening of athletes are highly variable in different countries and organizations and even existing policies are not uniformly enforced.
Androgens ; adverse effects ; pharmacology ; physiology ; Doping in Sports ; Humans ; Sports ; Weight Lifting

Adult ; Athletes ; Electroencephalography ; Female ; Humans ; Male ; Sports ; physiology

Catecholamines ; blood ; Heart Rate ; Humans ; Water Sports ; physiology

The polar sports tester made in Finland as one of the most widespread instruments in physical training is of importance for sports training. In this paper, we have developed a set of system for analysis of physical training workload using the measured data of the Polar Sports Tester, and have established a set of analysis indices and reports of the physical training workload, including five categories and 127 quantitative indices. It can reflect the distribution of physical workload and provide a series of parameters for coaches to direct scientific training and raise sport level.
Adaptation, Physiological ; physiology ; Gymnastics ; Humans ; Models, Biological ; Physical Endurance ; physiology ; Software ; Sports ; physiology

Phonocardiogram exercise testing(PCGET) is a recently developed method for evaluating cardiac contractility and the cardiac reserve of patients with heart disease and of healthy subjects. In order to test the reliability of PCGET method in physical sport, the present author conducted a clinical study. The ratio of the amplitude of the first heart sound after PCGET to that recorded at rest was defined as an indicator, i.e. cardiac contractility reserve index (CCRI). PCGET was performed on 30 athletes and 30 non-athletes. The results showed that the average of CCRI was 10.139 +/- 2.631 in 30 athletes and 6.612 +/- 3.104 in 30 non-athletes. There was a significant difference between CCRI of the two groups (P < 0.01). Thus, PCGET might be a noninvasive, convenient and inexpensive technique to evaluate the cardiac reserve quantitatively for athletes.
Adolescent ; Adult ; Exercise Test ; methods ; Feasibility Studies ; Humans ; Myocardial Contraction ; physiology ; Phonocardiography ; methods ; Sports ; physiology

Body Mass Index ; Female ; Humans ; Male ; Oxygen ; metabolism ; Oxygen Consumption ; physiology ; Sports ; physiology

PURPOSE: The purpose of this study was to retrospectively describe the childhood sports activity level of Korean adult men and women and to determine whether a higher level of childhood sports activity was positively associated with adult bone mineral density. METHODS: A cross-sectional study of 100 Korean men (n=40) and women (n=60) was completed. Participants completed a detailed lifetime sports activity questionnaire and had their bone mineral density of the femur and lumbar spine measured using dual energy x-ray densitometry (DEXA). All sports activities were classified into four categories of peak strain score on the basis of ground reaction forces (GRF). RESULTS: During the age of high school, women and men who participated in a high intensity sports activity demonstrated higher bone density in the femur site after adjustment for the effects of body weight, fat body mass, lean body mass, the level of calcium intake, and breast feeding period than those who did not participate in sports activity at all. CONCLUSION: These results highlight the need to participate in high intensity sports activity during high school age as a means of increasing peak bone mass in the femur site.
Sports/*physiology ; Male ; Korea ; Humans ; Female ; Densitometry, X-Ray ; *Bone Density ; Body Constitution ; Body Composition ; Adult