lactate

Introduction : Sleep deprivation is one of common phenomena in athletes. The aim of the present study was to investigate the influence of arginine supplementation following sleep deprivation on carbohydrate and fat metabolism, balance and fatigue index in female athletic students. Methods: The study population included all undergraduate female students of Sport Sciences at Imam Khomeini International University (age: 22.2± 2.16 years, BMI: 230.15±2.59 kg/m<sup>2 ) of whom 8 volunteered took part in the research. All experiments were performed in laboratory of university in 2020. Subjects were classified into four groups: Control, Sleep deprivation, Arginine and Arginine-sleep deprivation. Lactometer was used to measure blood lactate. Best Balance device was used to measure balance and GAS Analyzer was used to measure metabolism. Data was analyzed by analysis of covariance (ANCOVA). Results: Sleep deprivation significantly decreased static balance ( P =0.01) and dynamic balance ( P = 0.004) while arginine consumption resulted in improved static balance in sleep deprivation arginine group ( P =0.03). It was also shown that lactic acid levels were lower in the two groups that took arginine than in the groups that did not take arginine ( P ≤0.05). Conclusion: Arginine consumption can improve static and dynamic balance as well as mitigate side effects of sleep deprivation on static balance.

Background: Researchers have studied practical applications of high-intensity interval training and hypoxic training. PGC-1α, IGF-I, and HIF-1α are generated from high-intensity interval training and affect muscle cells. Altitude training also produces HIF-1α, which induces erythropoietin and increases the number of red blood cells. However, due to the limit on training intensity and cycle, it was replaced by normobaric hypoxia training. Purpose: To investigate the effects of 2-day high-intensity interval training on muscular anaerobic metabolism at varying oxygen concentrations for 2 days. Method: Ten subjects performed 2 consecutive days of intermittent hypoxia-hyperoxic training (IHHT); intensity of training was determined by the sprint test results. IHHT comprised 4 sets of 3 repetitions for 40 seconds (4 × 3 × 40 s); the intensity and oxygen concentration were 80% of maximal effort and 13% oxygen for the first and third sets, and were 90% of maximal effort and 21% oxygen for the second and fourth set; participants walked for 3 min wearing an oxygen mask (O2 80%) before each set. Differences in biological parameters between the two days of training was analyzed by t-test. Results: The difference of mean lactate levels between two days were 0.96 ± 0.75 mmol/l at Set 3 (P = .003) and 1.05 ± 1.12 mmol/l at Set 4 (P = .016), respectively. Mean ammonia concentrations at Set 4 were 117.70 ± 29.8 μmol/l for the first day and 94.50 ± 14.45 μmol/l for the second day (P = .057). The difference of heart rate were 4.20 ± 5.05 min-1 at Set 1 (P = .027) and 4.00 ± 5.48 min-1 at Set 2 (P = .046). Conclusions: Two-day intermittent hypoxia-hyperoxic training affected lactate and heart rate.

Background: High-velocity low-intensity actions result in reduced hemodynamic responses. Additionally, eccentric actions are associated with reduced hemodynamic and metabolic responses. Aim: This study aimed to investigate acute hemodynamic, hematological, and electrocardiographic responses to high-velocity low-intensity concentric resistance exercise (HVLICRE) and low-velocity high-intensity eccentric resistance exercise (LVHIERE) in healthy young adults. Materials and Methods: In this study, 16 healthy young men were divided into two groups (HVLICRE: 40% 1RM, LVHIERE: 80% 1RM). The exercise protocol consisted of five sets of 10 repetitions, with 90 sec of rest between the sets and a two-second interval between actions. For data analysis, repeated measures ANOVA, one-way ANOVA, and Bonferroni's post hoc test were performed at a significance level of P ≤0.05. Results: LVHIERE led to greater RPE ( P ≤0.05), compared to HVLICRE. Also, LVHIERE was associated with a significant increase in the activity of the sympathetic nervous system and a significant decrease in the parasympathetic nervous system as compared to HVLICRE ( P ≤0.05). Conclusion: HVLICRE and LVHIERE produced similar effects on blood glucose, serum lactate, hematocrit, systolic and diastolic blood pressure and heart rate. LVHIERE can be investigated as part of the strategy of rehabilitation programs in future studies.