The aim of this study was to compare the effects of 5-week high-intensity interval training (HIIT) and moderate-to-vigorous intensity continuous training (MVCT) on cardiometabolic health outcomes and enjoyment of exercise in obese young women. A randomized controlled experiment was conducted that involved thirty-one obese females (age range of 18–30) randomly assigned to either HIIT or MVCT five-week training programs. Participants in HIIT condition performed 20 min of repeated 8 s cycling interspersed with 12 s rest intervals, and those in MVCT condition cycled continuously for 40 min at 60–80% of peak oxygen consumption ( O_2peak), both for four days in a week. Outcomes such as O_2peak, body composition estimated by bioimpedance analysis, blood lipids, and serum sexual hormones were measured at pre-and post-training. The scores of Physical Activity Enjoyment Scale (PAES) were collected during the intervention. After training, O_2peak increased significantly for both training programs (9.1% in HIIT and 10.3% in MVCT) (p = 0.010, η² = 0.41). Although MVCT group had a significant reduction in total body weight (TBW, −1.8%, p = 0.034), fat mass (FM, - 4.7%, p = 0.002) and percentage body fat (PBF, −2.9%, p = 0.016), there were no significant between-group differences in the change of the pre- and post-measures of these variables. The HIIT group had a higher score on PAES than the MVCT group during the intervention. For both conditions, exercise training led to a decline in resting testosterone and estradiol levels, but had no significant effect on blood lipids. Both HIIT and MVCT are effective in improving cardiorespiratory fitness and in reducing sexual hormones in obese young women; however, HIIT is a more enjoyable and time-efficient strategy. The mild-HIIT protocol seems to be useful for at least maintaining the body weight among sedentary individuals.

The nature and kinetics of postexercise cardiac troponin (cTn) appearance is poorly described and understood in most athlete populations. We compared the kinetics of high-sensitivity cTn T (hs-cTnT) after endurance running in training-matched adolescents and adults. Thirteen male adolescent (mean age: 14.1 ± 1.1 yr) and 13 male adult (24.0 ± 3.6 yr) runners performed a 90-min constant-load treadmill run at 95% of ventilatory threshold. Serum hs-cTnT levels were assessed preexercise, immediately postexercise, and at 1, 2, 3, 4, 5, 6, and 24 h postexercise. Serum NH₂-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels were recorded preexercise and 3, 6, and 24 h postexercise. Left ventricular function was assessed preexercise, immediately postexercise, and 6 h postexercise. Peak hs-cTnT occurred at 3–4 h postexercise in all subjects, but was substantially higher ( P < 0.05) in adolescents [median (range): 211.0 (11.2–794.5) ng/l] compared with adults [median (range): 19.1 (9.7–305.6) ng/l]. Peak hs-cTnT was followed by a rapid decrease in both groups, although adolescent data had not returned to baseline at 24 h. Substantial interindividual variability was noted in peak hs-cTnT, especially in the adolescents. NT-pro-BNP was significantly elevated postexercise in both adults and adolescents and remained above baseline at 24 h in both groups. In both groups, left ventricular ejection fraction and the ratio of early-to-atrial peak Doppler flow velocities were significantly decreased immediately postexercise. Peak hs-cTnT was not related to changes in ejection fraction, ratio of early-to-atrial peak Doppler flow velocities, or NT-pro-BNP. The present data suggest that postexercise hs-cTnT elevation 1) occurred in all runners, 2) peaked 3–4 h postexercise, and 3) the peak hs-cTnT concentration after prolonged exercise was higher in adolescents than adults.

Context: Good sleep is an important recovery method for prevention and treatment of overtraining in sport practice. Whether sleep is regulated by melatonin after red-light irradiation in athletes is unknown. Objective: To determine the effect of red light on sleep quality and endurance performance of Chinese female basketball players. Design: Cohort study. Setting: Athletic training facility of the Chinese People's Liberation Army and research laboratory of the China Institute of Sport Science. Patients or Other Participants: Twenty athletes of the Chinese People's Liberation Army team (age = 18.60 ± 3.60 years) took part in the study. Participants were divided into red-light treatment (n = 10) and placebo (n = 10) groups. Intervention(s): The red-light treatment participants received 30 minutes of irradiation from a red-light therapy instrument every night for 14 days. The placebo group did not receive light illumination. Main Outcome Measure(s): The Pittsburgh Sleep Quality Index (PSQI) questionnaire was completed, serum melatonin was assessed, and 12-minute run was performed at preintervention (baseline) and postintervention (14 days). Results: The 14-day whole-body irradiation with red-light treatment improved the sleep, serum melatonin level, and endurance performance of the elite female basketball players (P < .05). We found a correlation between changes in global Pittsburgh Sleep Quality Index and serum melatonin levels (r = −0.695, P = .006). Conclusions: Our study confirmed the effectiveness of body irradiation with red light in improving the quality of sleep of elite female basketball players and offered a nonpharmacologic and noninvasive therapy to prevent sleep disorders after training.