We examined effects of a 20-min nap following 3 h of sleep deprivation on brain wave activity, auditory reaction time, the running-based anaerobic sprint test, leg muscle strength and the rating of perceived exertion in male college soccer players. Eleven players underwent three sleep conditions; normal sleep, sleep deprivation and 20-min nap after sleep deprivation. The sleep deprivation demonstrated an increase in the mean power of delta waves over the frontal area and a decrease in the mean power of alpha waves over the parietal area compared to the normal sleep. The nap and the sleep deprivation showed an increase in auditory reaction time compared with those in the normal sleep. The sleep deprivation demonstrated a decrease in the running-based anaerobic sprint test compared to the normal sleep, whereas the nap has partially reversed only minimal power and average power of the running-based anaerobic sprint test. The nap showed a recovery effect on leg muscle strength, but not on the rating of perceived exertion compared with the sleep deprivation. Thus, a 20-min nap after sleep deprivation did not completely return brain activity back to active state and did not entirely reverse the negative impact of sleep deprivation on soccer performance in soccer players.

New Zealand blackcurrant (NZBC) extract affects cardiovascular and metabolic responses during rest and exercise in Caucasian men. Ethnicity and nutritional habits may affect responses to nutritional ergogenic aids. We examined the effects of NZBC extract on cardiovascular, metabolic, and physiological responses during seated rest and moderate-intensity exercise in Southeast Asian men. Seventeen healthy Thai men (age: 22 ± 3 years; body mass index (BMI): 21.8 ± 1.1 kg·m⁻²) participated. Resting metabolic equivalent (1-MET) was measured (Oxycon™ mobile, Germany), and an incremental walking protocol was completed to establish the relationship between walking speed and MET. In a double-blind, randomized, placebo-controlled, crossover design, cardiovascular (Physioflow, n = 12) and physiological responses (Oxycon, n = 17) were measured during both seated rest and a 30-min treadmill walk at five metabolic equivalent (5-MET), with either a seven-day intake of placebo (PL) or two capsules of NZBC extract (each 300 mg capsule contains 35% blackcurrant extract) with a 14-day washout. Paired t-tests were used with significance accepted at p < 0.05 and a trend for 0.05 > p ≤ 0.10. During 30 min of treadmill walking at 5-MET, no differences were observed for heart rate and substrate oxidation. With intake of NZBC during treadmill walking, there was a trend for increased stroke volume by 12% (PL: 83.2 ± 25.1; NZBC: 93.0 ± 24.3 mL; p = 0.072) and cardiac output increased by 12% (PL: 9.2 ± 2.6; NZBC: 10.3 ± 2.8 L·min⁻¹; p = 0.057). Systemic vascular resistance decreased by 10% (PL: 779 ± 267; NZBC: 697 ± 245 dyn·s·cm⁻⁵; p = 0.048). NZBC extract had no effect on metabolic, physiological, and cardiovascular parameters during seated rest and exercise-induced fat oxidation in Thai men, in contrast to observations in Caucasian men. During treadmill walking, Thai men showed cardiovascular response, indicating vasodilatory effects during moderate-intensity exercise with the intake of NZBC extract. Our findings suggest that the ergogenic responses to anthocyanin intake from New Zealand blackcurrant may be ethnicity-dependent.

[Purpose] We examined cardiorespiratory and metabolic changes across the 1st (G1), 2nd (G2) and 3rd (G3) trimesters in pregnant women. [Subjects and Methods] Forty-two healthy, active, non-smoking, pregnant women participated in this study. They were divided into G1, G2 and G3 groups depending on their mean gestational ages at the time of testing which were 10.5 ±2.9, 19.2 ±3.4, and 33.3 ±2.4 weeks of gestation, respectively. Cardio-respiratory and metabolic variables, VO2 (oxygen consumption), VCO2 (carbon dioxide production), and VE (minute ventilation), were measured using indirect calorimetry (IC, gas analyser) to estimate ventilatory equivalents of oxygen (VE/VO2) and carbon dioxide (VE/VCO2), RER (respiratory exchange ratio) and REE (resting energy expenditure). [Results] Women in the late pregnancy period had higher resting VCO2 and RER, whereas the VE/VCO2 ratio was significantly lower than in G1 and in G2. Even though the values of VO2 and REE increased throughout the course of pregnancy, no significant differences were found. [Conclusion] In pregnant women, resting cardiorespiratory and metabolic variables continuously changed throughout the 3 trimesters. Changes in VE/VCO2 and RER indicate shifting metabolic energy substrates. In addition, changes in cardiorespiratory variables, in parallel with gas exchange, indicate a better gas exchange process.