Objective This study examined the effects of short-term betaine supplementation on muscle endurance, plasma lactate, testosterone and cortisol levels, and the testosterone to cortisol (T/C) ratio in response to acute resistance exercise (RE). Method Using a double-blind, crossover study design, 10 handball players (age ± SD = 16 ± 1 yrs) without prior-structured RE experience performed a high-intensity RE session (leg press followed by bench press; 5 sets to volitional fatigue using 80% baseline 1 repetition maximum (1RM)), before and after 14 days of either placebo (maltodextrin) or betaine (2.5 g·d −1 ) supplementation. A 30-day washout period separated each treatment. 48 h prior to testing sessions, participants recorded their food intake and did not perform strenuous exercise. Venous blood was sampled before supplementation, and before and after each RE session. Results After betaine supplementation, participants performed more repetitions ( p < 0.001) during the leg press (Betaine: 35.8 ± 4.3; Placebo: 24.8 ± 3.6, Cohen’s d = 2.77) and bench press (Betaine: 36.3 ± 2.6; Placebo: 26.1 ± 3.5, Cohen’s d = 3.34). Betaine resulted in lower post-exercise cortisol (Betaine: 7.6 ± 1.7; Placebo: 13 ± 3.4 µg.dL −1 , p = 0.003, generalized eta squared ( ) = 0.49) and lactate (Betaine: 5.2 ± 0.3; Placebo: 6 ± 0.3 mmol.L −1 , p < 0.001, = 0.96) and higher total testosterone (Betaine: 15.2 ± 2.2; Placebo: 8.7 ± 1.7 ng.mL −1 , p < 0.001, = 0.87) and T/C ratio (Betaine: 0.21 ± 0.05; Placebo: 0.07 ± 0.02, p < 0.001, = 0.82). Conclusions Two weeks of betaine supplementation improved upper- and lower-body muscle endurance and influenced indices of endocrine function following an acute session of high-intensity RE in adolescent handball players.

The evidence shows that the sedentary life increases the risk of coronary heart disease and decreases physical fitness. However, this study aimed to evaluate the cardiovascular risk factors and health-related physical fitness of employees at General Directorate of Youth and Sport of Mazandaran Province in Iran. For this purpose, using random sampling method, 40 employees (age mean= 35.54 ± 7.63 years old, body mass index= 22.61 ± 9.70 kg/m 2 ) at General Directorate of Youth and Sport of Mazandaran were selected as sample. Then, after collecting necessary data by questionnaire, the health-related physical fitness was measured in terms of cardiorespiratory endurance, muscular endurance, body fat percentage, strength, and flexibility. Also, the sphygmomanometer was used to measure heart rate (HR) and blood pressure (BP). Finally, 5 ml blood was taken from subjects to evaluate cardiovascular risk factors including total cholesterol (TC), triglyceride (TG), fasting blood sugar (FBS), low density lipoprotein (LDL), and high density lipoprotein (HDL). The findings showed that there was no significant difference between TC, TG, LDL, HDL, systolic blood pressure (SBP), and diastolic blood pressure (DBP) of employees at General Directorate of Youth and Sport of Mazandaran and desirable situation. However, there was significant difference between health-related physical fitness of employees and desirable situation (P < 0.05). It was concluded that due to undesirable situation of physical fitness of employees, it is necessary to take measures to emphasize regular exercise programs and promote their fitness and health.