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Background/Objective Mental health problems are common among adolescents and greatly influenced by stressful events. This study sought to assess the prevalence and correlates of insomnia, depressive and anxiety symptoms among Chinese adolescents during the COVID-19. Method: Cross-sectional study (N = 1,794 adolescents, mean age = 15.26) was conducted in May 2020. An online survey was used to collect socio-demographic data, COVID-related fear (COVID-fear), nutrition, physical activity (PA) level and the symptoms of insomnia, depression and anxiety. Results: The prevalence of insomnia, depressive and anxiety symptoms was 37.80%, 48.20% and 36.70%, respectively, among Chinese adolescents during the pandemic. Generalized linear models revealed that female, left behind children, and students with greater COVID-fear tended to report symptoms of insomnia, depression and anxiety concurrently. After adjusting for socio-demographic factors and COVID-fear, better nutritional status and moderately active PA were both associated with lower levels of depressive and anxiety symptoms, while highly active PA was associated with lower levels of insomnia, depressive and anxiety symptoms. Conclusions: These findings suggest that more attention should be paid to psychological health among adolescents while combating COVID-19. To promote adolescents’ mental health, educators should help adolescents develop a healthy lifestyle with balanced diet and regular exercise.

Problematic smartphone use (PSU) has become a prevalent issue worldwide. Previous studies suggest that physical exercising may effectively reduce smartphone users’ addiction levels. Comparisons and further evaluations on the long-term effects of different types of exercise-based interventions on treating PSU remain to be investigated. Objective. We investigated if group-based basketball and Baduanjin exercise (a type of Qigong) would reduce PSU and improve the mental health of college students and whether such effects would be sustained. A twelve-week experiment was conducted, where 96 eligible Chinese college students with PSU were randomly assigned to two intervention arms (i.e., basketball and Baduanjin exercises) and a control arm. Outcome measures, including PSU (measured by the Mobile Phone Addiction Index in Chinese (MPAI)) and mental health indices for anxiety (measured by Self-Rating Anxiety Scale (SRAS)), loneliness (measured by the short-form of the UCLA Loneliness Scale (UCLA-LS)), inadequacy (measured by the revised Janis and Field’s Feelings of Inadequacy Scale (FIS)), and stress (measured by the Chinese version of Perceived Stress Scale (CPSS)) were collected at the baseline, the end of week 12, and the two-month follow-up. A Generalized Estimating Equations (GEE) model for longitudinal data was utilized in analyses. Results. Both exercise interventions demonstrated significant effects on decreasing PSU (basketball: p < 0.01 ; Baduanjin: p < 0.01 ), feelings of anxiety (basketball: p < 0.01 ; Baduanjin: p = 0.04 ), loneliness (basketball: p < 0.01 ; Baduanjin: p < 0.01 ), inadequacy (basketball: p < 0.01 ; Baduanjin: p < 0.01 ), and perceived stress (basketball: p < 0.01 ; Baduanjin: p = 0.04 ), at the end of interventions. At two months after interventions, both exercise interventions demonstrated significant effects on decreasing PSU (basketball: p < 0.05 ; Baduanjin: p < 0.05 ), feelings of anxiety (basketball: p < 0.01 ; Baduanjin: p = 0.03 ), loneliness (basketball: p < 0.01 ; Baduanjin: p < 0.01 ), and inadequacy (basketball: p < 0.01 ; Baduanjin: p = 0.01 ), but not for feeling of stress. Furthermore, group-based basketball demonstrated larger improvements for all these significant results on reducing PSU and meanwhile improving their related mental health parameters among college students.

ObjectiveThe current study aimed at determining effects of Tai Chi as an example of a combined motor-cognitive exercise relative to regular walking as an example of an exercise without cognitive demands on cognitive functioning and the functional and structural integrity of the brain in the elderly.MethodsHealthy elderly women with at least 6 years of regular Tai Chi or brisk walking exercise were recruited and underwent cognitive assessment via the Montreal Cognitive Assessment and brain structural and resting state functional MRI assessments.ResultsEpisodic memory in Tai Chi group was superior to that of the walking group; (2) higher gray matter density in inferior and medial temporal regions, including the hippocampal formation; (3) higher ReHo in temporal regions, specifically the fusiform gyrus and hippocampal formation (4) significant partial correlations were found between the gray matter density of the left hippocampus and episodic memory in the whole sample (5) significant partial correlations were observed between the ReHo in left hippocampus, left parahippocampal, left fusiform and delayed memory task was observed among all subjects.ConclusionThe present study suggest that long-term Tai Chi practice may improve memory performance via remodeling structure and the function of the hippocampal formation.

The purpose of this study was to examine the effects of a short-term ketogenic diet (KD) on body composition and cardiorespiratory fitness (CRF) in overweight/obese Chinese females. Twenty young females [age: 21.0 ± 3.7 years, weight: 65.5 ± 7.7 kg, body mass index (BMI): 24.9 ± 2.7 kg⋅m–2] consumed 4 weeks of a normal diet (ND) as a baseline and then switched to a low-carbohydrate, high-fat, and adequate protein KD for another 4 weeks. With the same daily caloric intake, the proportions of energy intake derived from carbohydrates, proteins, and fats were changed from 44.0 ± 7.6%, 15.4 ± 3.3%, 39.6 ± 5.8% in ND to 9.2 ± 4.8%, 21.9 ± 3.4%, and 69.0 ± 5.4% in KD. The results showed that, without impairing the CRF level, the 4-week KD intervention significantly reduced body weight (−2.9 kg), BMI (−1.1 kg⋅m–2), waist circumference (−4.0 cm), hip circumference (−2.5 cm), and body fat percentage (−2.0%). Moreover, fasting leptin level was lowered significantly, and serum levels of inflammatory markers (i.e., TNF-α and MCP-1) were unchanged following KD. These findings suggest that KD can be used as a rapid and effective approach to lose weight and reduce abdominal adiposity in overweight/obese Chinese females without exacerbating their CRF.

Visceral fat loss in response to four-cycle ergometer training regimens with explicit differences in exercise intensity and modality was compared. Fifty-nine obese young women (body fat percentage ≥ 30%) were randomized to a 12-week intervention consisting of either all-out sprint interval training (SITall-out , n = 11); supramaximal SIT (SIT120 , 120% V˙ O2peak , n = 12); high-intensity interval training (HIIT90 , 90% V˙ O2peak , n = 12), moderate-intensity continuous training (MICT, 60% V˙ O2peak , n = 11), or no training (CON, n = 13). The total work done per training session in SIT120 , HIIT90 , and MICT was confined to 200 kJ, while it was deliberately lower in SITall-out . The abdominal visceral fat area (AVFA) was measured through computed tomography scans. The whole-body and regional fat mass were assessed through dual-energy X-ray absorptiometry. Pre-, post-, and 3-hour post-exercise serum growth hormone (GH), and epinephrine (EPI) were measured during selected training sessions. Following the intervention, similar reductions in whole-body and regional fat mass were found in all intervention groups, while the reductions in AVFA resulting from SITall-out , SIT120 , and HIIT90 (>15 cm2 ) were greater in comparison with MICT (

Low-carbohydrate diets (LCs) seem effective on weight reduction and maintenance. However, the affect and enjoyment of exercise during LCs is not clear. The purpose of the present study was to compare the psychological responses to high-intensity interval training (HIIT) and to moderate-intensity continuous training (MICT) during the consumption of a 4-week LC diet in overweight young women. With LCs (~10% carbohydrate, 65%&ndash, 70% fat, 20%&ndash, 25% protein), forty-three eligible women (age: 20.9 &plusmn, 3.1 years, body weight: 65.8 &plusmn, 8.2 kg) were randomly assigned to one of three groups: HIIT (10 sets of 6 s all-out cycling interspersed with 9 s of rest), MICT (30 min cycling at 50%&ndash, 60% of peak oxygen consumption, V̇O2peak) or no-exercise controls (CON). Anthropometric indices and V̇O2peak were measured pre- and post-training. Feeling Scale (FS), Felt Arousal Scale (FAS), Exercise Enjoyment Scale (EES), and Physical Activity Enjoyment Scale (PACES) scores were collected before and immediately after each training session throughout the study. After intervention, all three groups reduced by more than 2.5 kg of body weight whereas both exercise groups improved ~15% V̇O2peak. Participants in the HIIT and MICT group exhibited similar affect points as indicated by FS and FAS. Post-exercise enjoyment scores in PACES were lower in HIIT (73&ndash, 78 points) than MICT (83&ndash, 87 points) despite similarly positive responses being observed in EES (corresponding to ~4 points of a 7-point scale). Short-term LCs were effective in weight loss and exercise training had an additive improvement on cardiorespiratory fitness. The overweight young women had similar affect valence, arousal levels, and comparable pleasurable feelings to HIIT and MICT with LCs. Furthermore, as indicated by PACES, MICT was more enjoyable which may elicit better adherence, whereas HIIT with LCs seems to be more arduous despite its time-efficiency.

Background/Objective: This study examined whether time spent at high rates of oxygen consumption (VO2) during 6-s sprint interval exercises (SIE) is a function of recovery interval duration. Methods: In a randomised crossover study, thirteen male endurance runners performed 40 × 6-s all-out sprints interspersed with 15-s, 30-s and 60-s passive recovery intervals (SIE15, SIE30, and SIE60 trials respectively), and a work duration-matched Wingate-SIE (8 × 30-s all-out sprints with 4-min passive recovery, SIEWin trial). The accumulated exercise time at ≥ 80%, 85%, 90%, 95% and 100% of VO2max, and maximum heart rate (HRmax) in the four trials were compared. Results: During the 6-s SIEs, accumulated time spent at all selected high rates of VO2max increased as recovery time decreased, whilst the SIE work rate decreased (p .05), and longer than that in SIE60 (20 ± 14 s, p

Benefits of performing sprint interval training (SIT) under hypoxic conditions on improving cardiorespiratory fitness and body composition have been well-documented, yet data is still lacking regarding affective responses to SIT under hypoxia. This study aimed to compare affective responses to SIT exercise under different oxygen conditions. Nineteen active males participated in three sessions of acute SIT exercise (20 repetitions of 6 s of all-out cycling bouts interspersed with 15 s of passive recovery) under conditions of normobaric normoxia (SL: PIO2 150 mmHg, FIO2 0.209), moderate hypoxia (MH: PIO2 117 mmHg, FIO2 0.154, simulating an altitude corresponding to 2500 m), and severe hypoxia (SH: PIO2 87 mmHg, FIO2 0.112, simulating an altitude of 5000 m) in a randomized order. Perceived exertions (RPE), affect, activation, and enjoyment responses were recorded before and immediately after each SIT session. There were no significant differences across the three conditions in RPE or the measurements of affective responses, despite a statistically lower SpO2 (%) in severe hypoxia. Participants maintained a positive affect valence and reported increased activation in all the three SIT conditions. Additionally, participants experienced a medium level of enjoyment after exercise as indicated by the exercise enjoyment scale (EES) and physical activity enjoyment scale (PACES). These results indicated that performing short duration SIT exercise under severe hypoxia could be perceived as pleasurable and enjoyable as performing it under normoxia in active male population.

This study aimed to examine the effects of four weeks of a low-carbohydrate diet (LC) and incorporated exercise training on body composition and cardiometabolic health. Fifty-eight overweight/obese Chinese females (age: 21.2 &plusmn, 3.3 years, body mass index (BMI): 25.1 &plusmn, 2.8 kg/m2) were randomly assigned to the control group (CON, n = 15), the LC control group (LC-CON, n = 15), the LC and high-intensity interval training group (LC-HIIT, n = 15), or the LC and moderate-intensity continuous training group (LC-MICT, n = 13). Subjects consumed a four week LC, whereas LC-HIIT and LC-MICT received extra training 5 d/week (LC-HIIT: 10 &times, 6 s cycling interspersed with 9 s rest, MICT: 30 min continuous cycling at 50&ndash, 60% VO2peak). After intervention, the three LC groups demonstrated significant reductions in body weight (&minus, 2.85 kg in LC-CON, &minus, 2.85 kg in LC-HIIT, &minus, 2.56 kg in LC-MICT, p &lt, 0.001, &eta, 2 = 0.510), BMI (p &lt, 2 = 0.504) and waist-to-hip ratio (p &lt, 2 = 0.523). Groups with extra training (i.e., LC-HIIT and LC-MICT) improved VO2peak by 14.8 and 17.3%, respectively. However, fasting glucose and blood lipid levels remained unchanged in all groups. Short-term LC is a useful approach to improve body composition in overweight/obese Chinese females. Incorporated exercise training has no additional effects on weight loss, but has additional benefits on cardiorespiratory fitness, and HIIT is more time efficient than the traditional MICT (2.5 min vs. 30 min).

Purpose: Previous research has evaluated the effects of acute hypoxia exposure on cognitive function, notably executive function. No studies, to date, have evaluated the effects of acute hypoxia exposure on memory interference, which was the purpose of this experiment. Methods: A within-subjects, counterbalanced experimental design was employed, with condition (hypoxia vs. normoxia) and time (immediate vs. delayed) being the independent variables. Participants (N = 21, Mage = 21.0 years) completed two laboratory visits, involving 30 min of exposure to either hypoxia (FIO2 = 0.12) or normoxia (FIO2 = 0.21). Following this, they completed a memory interference task (AB/AC paradigm), assessing immediate and delayed proactive and retroactive interference. Results: For retroactive interference, we observed a significant main effect for condition, F(1, 20) = 5.48, p = 0.03, ƞ2 = 0.10, condition by time interaction, F(1, 20) = 4.96, p = 0.03, ƞ2 = 0.01, but no main effect for time, F(1, 20) = 1.75, p = 0.20, ƞ2 = 0.004. Conclusion: Our results demonstrate that acute hypoxia exposure was facilitative in reducing memory interference. We discuss these findings in the context of the potential therapeutic effects of acute hypoxia exposure on synaptic plasticity.

An elevation in cardiac troponin T (cTnT), as a highly specific biomarker of cardiomyocyte damage, after moderate-intensity continuous exercise (MCE) has been described. The exercise-induced cTnT response distorts the diagnostic role of the cTnT assay. Although high-intensity interval exercise (HIE) is growing in popularity and concerns remain about its safety, available data related to cTnT release after HIE is limited, which hampers the use of HIE as a health intervention. Here, we present three representative HIE protocols [traditional HIE (repeated 4 min cycling at 90% V̇O2max interspersed with 3 min rest, 200 kJ/session); sprint interval exercise (SIE, repeated 1 min cycling at 120% V̇O2max interspersed with 1.5 min rest, 200 kJ/session); and repeated sprint exercise (RSE, 40 x 6 s all-out sprints interspersed with 9 s rest)] and one representative MCE protocol (continuous cycling exercise at an intensity of 60% V̇O2max, 200 kJ/session). Forty-seven sedentary, overweight young women were randomly assigned to one of four groups (HIE, SIE, RSE, and MCE). Six bouts of respective exercise were performed by every single group, with each being 48 h apart. Meanwhile, for four groups, the duration of the entire testing period was identical, being 10 days. Before and after the first and final exercise bouts, an assessment was conducted of cTnT. The current study provides a frame of reference giving a clear picture of how a specific exercise session affects the circulating cTnT concentration at the early stage of training. The information may assist with clinical interpretations of post-exercise cTnT elevation and guide the prescription of exercise, especially for HIE.

OBJECTIVES: It is unclear whether exercise modality (moderate-intensity continuous [MCE]; high-intensity interval [HIE]) and menstrual cycle phase (follicular [FP]; luteal [LP]), individually or in combination, mediate the commonly observed exercise-induced elevation in cardiac troponin T (cTnT). This study examines cTnT responses to MCE and HIE during both the FP and LP. DESIGN: Randomised crossover study. METHODS: Seventeen healthy, eumenorrheic women completed four trials including MCE (60% VO2max steady-state cycling until 300kJ) and work-equivalent HIE (repeated 4-min cycling at 90% VO2max interspersed with 3-min rest) during both the FP and LP. The FP and LP were verified based on ovarian hormones. Serum cTnT was assessed using a high-sensitivity assay before, immediately after, and 1 (1HR), 3 (3HR) and 4 (4HR) hours after exercise. cTnT values were corrected for plasma volume changes. RESULTS: cTnT was significantly elevated (p0.05) in peak post-exercise cTnT, which mostly occurred at 3HR, was seen among the four trials (median [range], ngl-1: 5.2 [1.7-18.1] after MCE during FP; 4.8 [1.7-24.9] after MCE during LP, 8.2 [3.9-24.8] after HIE during FP and 6.9 [1.7-23.1] after HIE during LP). CONCLUSIONS: A single 300kJ bout of both MCE or HIE resulted in a significant post-exercise increase in cTnT, with no differences in peak cTnT response between menstrual cycle phases or between exercise modes, but the cTnT elevation occurs slightly earlier after HIE.

Objective: The purpose of this study was to investigate the effects of Tai Chi (TC) on anthropometric parameters and physical fitness among children and adolescents with intellectual disabilities (ID). Methods: Sixty-six Chinese individuals engaged in sport-related extracurricular activities (TC and aerobic exercise (AE)) as exercise interventions or arts/crafts activities as a control condition (CON). The experimental protocol consisted of a baseline assessment, a 12-week intervention period, and a post-intervention assessment. Results: Significant interaction effect was only observed in the performance of a 6-min walk test. After 12 weeks of intervention, the AE group had significant changes in body mass index (p = 0.006, d = 0.11), sit-ups (p = 0.030 and d = 0.57), and 6-min walk test (p = 0.005, d = 0.89). Significant increases in vertical jump (p = 0.048, d = 0.41), lower-limb coordination (p = 0.008, d = 0.53), and upper-limb coordination (p = 0.048, d = 0.36) were observed in the TC group. Furthermore, the TC group demonstrated significantly greater improvements on balance compared to the control group (p = 0.011). Conclusions: TC may improve leg power and coordination of both lower and upper limbs, while AE may be beneficial for body mass index, sit-ups and cardiorespiratory fitness.

Objective: The purpose of this study was to investigate the effects of Tai Chi (TC) on arterial stiffness, physical function of lower-limb, and cognitive ability in adults aged over 60. Methods: This study was a prospective and randomized 12-week intervention trial with three repeated measurements (baseline, 6, and 12 weeks). Sixty healthy adults who met the inclusion criteria were randomly allocated into three training conditions (TC-24, TC-42, and TC-56) matched by gender, with 20 participants (10 males, 10 females) in each of the three groups. We measured the following health outcomes, including markers of atherosclerosis, physical function (leg power, and static and dynamic balance) of lower-limb, and cognitive ability. Results: When all three TC groups (p &lt, 0.05) have showed significant improvements on these outcomes but overall cognitive ability at 6 or 12 weeks training period, TC-56 appears to have superior effects on arterial stiffness and static/dynamic balance in the present study. Conclusions: Study results of the present study add to growing body of evidence regarding therapeutic TC for health promotion and disease prevention in aging population. Future studies should further determine whether TC-42 and TC-56 are beneficial for other non-Chinese populations, with rigorous research design and follow-up assessment.

Some studies have shown that resistance training combined with plyometric training is more time-efficient and effective for fitness development. The degree and frequency of combined training might influence the benefit of training to maintain time. To better understand this phenomenon of the degree and frequency of combined training in pre- and early pubertal boys, we have provided a more specific recommendation for physical education teachers thus that they are able to prescribe an exercise plan for their students in the physical education setting. We aimed to investigate the effects of combined training followed by 12 weeks of a reduced/detraining period on physical fitness and anthropometric features in 8 to 12-year old boys. Forty-six healthy boys were randomly assigned to either an experimental group (EG, n = 31) or a control group (CG, n = 15). Besides regular physical education classes (PE), participants in the EG performed a combined training program (resistance and plyometric training) twice weekly for 12 weeks. In the CG, participants only underwent PE classes twice per week. Then, the trained boys were randomly assigned to either a reduced training group (RTG, n = 14) or a training cessation group (TCG, n = 17). The RTG continued a reduced combined training program once a week with PE for additional 12 weeks. In the TCG, participants only kept their PE classes twice a week for 12 weeks. We assessed physical fitness performances (biceps curl, leg power, and running speed) and anthropometric features at baseline, after 12 weeks of combined training, and after 12 weeks of reduced training/detraining. We observed a significantly greater decrease in biceps girth in the EG (p = 0.049, d = 0.636), as compared to the CG. With regard to the physical fitness measures after the 12-week combined training, the EG showed significantly greater increase on biceps curl (p = 0.005, d = 0.92) and standing long jump (p = 0.015, d = 0.8) in comparison with the CG, whereas a significantly greater improvement on 30 m sprint speed (p = 0.031, d = 0.707) was observed in the EG, as compared to the CG. With regard to detraining and reduced training, results indicated a significantly greater increase on this outcome in the RTG (p = 0.038, d = 0.938), as compared to the TCG. Resistance training combined with plyometric training can be a safe and effective way to enhance the selected aspects of physical fitness, as well as reduce muscular girth in boys aged between 8 and 12 years. The frequency of one session per week in the combined training seems to provide an additional benefit to prevent leg power of lower limb from rapid deterioration.

This current meta-analysis review was conducted to examine the effectiveness of Qigong-based therapy on individuals with major depressive disorder. Six electronic databases (PubMed, PsycINFO, Cochrane Library, and Web of Science, Chinese National Knowledge Infrastructure, and Wangfang) were employed to retrieve potential articles that were randomized controlled trials. The synthesized effect sizes (Hedges’ g) were computerized to explore the effectiveness of Qigong-based therapy. Additionally, a moderator analysis was performed based on the control type. The pooled results indicated that Qigong-based therapy has a significant benefit on depression severity (Hedges’ g = −0.64, 95% CI −0.92 to −0.35, p < 0. 001, I2 = 41.73%). Specifically, Qigong led to significantly reduced depression as compared to the active control groups (Hedges’ g = −0.47, 95% CI −0.81 to −0.12, p = 0.01, I2 = 22.75%) and the passive control groups (Hedges’ g = −0.80, 95% CI −1.23 to −0.37, p < 0.01, I2 = 48.07%), respectively. For studies which reported categorical outcomes, Qigong intervention showed significantly improved treatment response rates (OR = 4.38, 95% CI 1.26 to 15.23, p = 0.02) and remission rates (OR = 8.52, 95% CI 1.91 to 37.98, p = 0.005) in comparison to the waitlist control group. Conclusions: Qigong-based exercises may be effective for alleviating depression symptoms in individuals with major depressive disorder. Future well-designed, randomized, controlled trials with large sample sizes are needed to confirm these findings.

Tai Chi (TC) can be considered safe and effective intervention to improve pain and pain-related functional disability. However, it is unclear that whether aging individuals with Chronic Non-Specific Low Back Pain (CNS-LBP) can achieve positive results. This study, therefore, attempted to explore the effects of TC on pain and functional disability in CNS-LBP patients aged 50 years old or above. Forty-three individuals (aged 50 years old or above) with CNS-LBP were randomly assigned into three groups: Chen-Style TC group (n = 15), Core Stabilization training (CST) group (n = 15), and control group (n = 13). Participants in the TC group participated in Chen-style TC training program (three 60-min sessions per week for 12 weeks), individuals in CST group received 12-week Core Stabilization exercise on the Swiss ball, whereas individuals in the control group maintained their unaltered lifestyle. Pain intensity as primary outcome was measured using the Visual Analogue Scale (VAS), A BiodexSystem 3 isokinetic dynamometer was used to measure knee and ankle joint position sense (JPS) as secondary outcomes at baseline and after the 12-week intervention. TC and CST have significant effects in VAS for CNS-LBP patients (p&lt, 0.01, TC group OR CST group versus control group in mean of the post-minus-pre assessment). However, the feature of joint position sense (JPS) of ankle inversion, ankle eversion and knee flexion did not occur, it showed no significant effects with TC and CST. TC was found to reduce pain, but not improve lower limb proprioception in patients with CNS-LBP. Future research with larger sample sizes will be needed to achieve more definitive findings on the effects of TC on both pain and lower limb proprioception in this population.

This study compared the effects of 12-week sprint interval training (SIT), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT) on cardiorespiratory fitness (VO2peak), body mass and insulin sensitivity in overweight females. Forty-two overweight women (age 21.2 ± 1.4 years, BMI 26.3 ± 2.5 kg·m-2) were randomized to the groups of SIT (80 × 6-s sprints + 9-s rest), and isoenergetic (300KJ) HIIT (~9 × 4-min cycling at 90% VO2peak + 3-min rest) and MICT (cycling at 60% VO2peak for ~ 61-min). Training intervention was performed 3 d·week-1 for 12 weeks. After intervention, all three groups induced the same improvement in VO2peak (~ +25%, p < 0.001) and a similar reduction in body mass (~ - 5%, p < 0.001). Insulin sensitivity and fasting insulin levels were improved significantly on post-training measures in SIT and HIIT by ~26% and ~39% (p < 0.01), respectively, but remain unchanged in MICT. In contrast, fasting glucose levels were only reduced with MICT (p < 0.01). The three training strategies are equally effective in improving VO2peak and reducing body mass, however, the SIT is time-efficient. High-intensity training (i.e. SIT and HIIT) seems to be more beneficial than MICT in improving insulin sensitivity. Abbreviations: BMI: body mass index; CVD: cardiovascular disease; HIEG: hyperinsulinaemic euglycaemic glucose; HIIT: high-intensity interval training; HOMA-IR: homeostasis model assessment of insulin resistance; HR: heart rate; MICT: moderate-intensity continuous training; RPE: ratings of perceived exertion; SIT: sprint interval training; T2D: type 2 diabetes; VO2peak: peak oxygen consumption.

Objective: This study is the first meta-analysis investigating the rehabilitative effects of Wuqinxi for patients with chronic obstructive pulmonary disease (COPD). Methods: Five electronic databases (PubMed, Web of Science, Scopus, CNKI, and Wanfang) from inception until early November 2018 were searched. All randomized controlled trials (RCT) using Wuqinxi as the main intervention component were included for meta-analysis. The pooled effect sizes (Standardized mean difference, SMD) were calculated to determine the magnitude of the Wuqinxi intervention effect. Moderator analysis was only conducted for total training time. Results: Overall results of the meta-analysis indicated that Wuqinxi exercise significantly improved exercise capability (SMD = 1.18, 95% CI 0.53 to 1.84, e < 0.001, I2 = 84.97%), FEV1 (SMD = 0.44, 95% CI 0.12 to 0.77, e < 0.001, I2 = 33.77%), FEV1% (SMD = 0.59, 95% CI 0.24 to 0.93, e < 0.001, I2 = 63.79%), FEV1/FVC (SMD = 0.65, 95% CI 0.37 to 0.93, e = 0.006, I2 = 44.32%) and CCQ (SMD = 1.23, 95% CI 0.31 to 2.14, e = 0.01, I2 = 93.32%). Conclusions: With no occurrence of adverse event, clinicians could try to incorporate Wuqinxi exercise into their first-line rehabilitation regime for COPD patients.

The risk of malignant arrhythmias is higher during extremely intense exercise and after its cessation. It is still unclear whether high-intensity interval exercise (HIE), an increasingly popular option in preventive and rehabilitative medicine, can lead to an impaired electrophysiological milieu, as revealed by QT interval prolongation on an electrocardiogram. This study investigated heart rate-corrected QT interval (QTc) dynamics during recovery from HIE in obese adults. In total, 13 obese males (age: 24.3 ± 4.6 years old; body mass index: 31.6 ± 4.1 kg/m2) underwent: (1) HIE: an HIE session of four 30-s all-out cycling efforts interspersed with 4‑min recovery periods; (2) REC: a recovery session 24 h after HIE; and (3) CON: a control session of no treatment. The QT interval was measured before HIE, REC, and CON, and then at 30-min intervals thereafter, for up to 3 h. QTc values were obtained using Bazett, Fridericia, Framingham, Hodges, and Rautaharju correction formulas. Acute HIE led to a significant increase in QTc for each correction (by 5–47 ms, all p

To compare postprandial glucose responses to high-intensity interval exercise (HIE) between obese and lean individuals.Thirty healthy young adult males (15 obese, 15 lean) ate a standardised meal, then performed HIE (4 × 30-s Wingate cycling/4-min rest) or a no-exercise control trial (CON). Blood glucose was measured preprandially and up to 150 min postprandially.Compared to CON, HIE reduced postprandial glucose concentrations at 120-150 min in obese (p 0.001) and lean men (p 0.05), with greater reductions in obese than lean subjects at 120 (-27.0% vs. -8.3%), 135 (-31.9% vs. -15.7%), and 150 min (-21.8% vs. -10.6%). The total glucose area under the curve (AUC) for the testing period was lower with HIE than CON among obese men (p 0.05), but not lean men (p 0.05). We found moderate correlations between body mass and postprandial glucose changes (r = 0.39-0.44, p 0.05), and between glucose AUC and body mass and fat free mass (r = 0.39-0.48, p 0.05).Our findings suggest that HIE may act as a time-efficient lifestyle intervention strategy for improving obesity-related diabetes risk factors, and might play a role in primary diabetes prevention for the healthy but sedentary population.

Low-volume, high-intensity exercise is a time-efficient method of inducing physiological responses and may also improve glucose homeostasis. Therefore, effects of two different volumes of sprint-interval cycling on post-prandial blood glucose were assessed.Twenty healthy young males undertook two Wingate anaerobic tests (2WAT), four Wingate anaerobic (4WAT) and without-exercise (CON) 90 min after eating a standard meal. Blood glucose was examined at 60, 90, 105, 120, 135 and 150 min post-prandially.2WAT and 4WAT both accelerated the decrease of blood glucose compared with CON (P0.05). There were significant reductions at 120 (4.45 ± 0.64 vs. 4.93 ± 0.9 vs. 5.68 ± 0.69), 135 (4.28 ± 0.50 vs. 4.48 ± 0.75 vs. 5.54 ± 0.6) and 150 min (4.64 ± 0.71 vs. 4.71 ± 0.73 vs. 5.36 ± 0.48, all P0.05). Blood glucose at 120 min was lower after 2WAT than 4WAT (4.45 ± 0.64 vs. 4.93 ± 0.9, P0.05), this producing a significant statistical interaction between groups and post-exercise time (P0.005).2WAT and 4WAT tests both accelerate the post-prandial decrease in blood glucose in young healthy males, 2WAT being superior to 4WAT in producing this response, even though 2WAT is easier to perform and less time consuming.

What is the central question of this study? Does exercise training impact resting and postexercise cardiac troponin T (cTnT) concentration? What is the main finding and its importance? This randomized controlled intervention study demonstrated that 12 weeks of either high-intensity interval training or moderate-intensity continuous training largely abolished the exercise-induced elevation in cTnT when exercise was performed at the same absolute intensity. There was no impact of training on resting cTnT or postexercise appearance of cTnT when exercise was performed at the same relative intensity. These findings provide new information that might help clinicians with decision-making in relationship to basal and postexercise values of cTnT in individuals with different training status.We evaluated the influence of 12 weeks of high-intensity interval training [HIIT; repeated 4 min cycling at 90% of maximal oxygen uptake (V̇O2max) interspersed with 3 min rest, 200-300 kJ per session, 3 or 4 days each week] and work-equivalent moderate-intensity continuous training (MICT; continuous cycling at 60% V̇O2max) on resting cardiac troponin T (cTnT) and the appearance of exercise-induced cTnT. Forty-eight sedentary obese young women were randomly assigned to HIIT, MICT or a control group. The V̇O2max and body composition were measured before and after training. At baseline, cTnT was assessed using a high-sensitivity assay at rest and immediately, 2 and 4 h after 45 min cycling at 60% V̇O2max. After a 12 week training period, cTnT was assessed before and after 45 min cycling at the same relative and absolute intensities as before training. Training led to higher V̇O2max and lower fat mass in both HIIT and MICT groups (all P 0.05). Before training, cTnT was significantly elevated in all three groups (by 35-118%, all P 0.05) with acute exercise. After training, both resting and postexercise cTnT concentrations (same relative intensity) were similar to pretraining values. In contrast, postexercise cTnT (same absolute intensity, which represented a smaller exercise stimulus) was not elevated from rest in both HIIT and MICT groups. In conclusion, 12 weeks of either HIIT or MICT largely abolished the postexercise elevation of cTnT concentration when exercise was performed at the same absolute intensity. There was, however, no impact of training on resting cTnT or postexercise appearance of cTnT for exercise performed at the same relative intensity.

Previous studies have investigated the effects of high-intensity interval training (HIIT) on cardiorespiratory fitness and body composition in overweight populations. However, the additive effect of HIIT and hypoxia on health parameters is not clear. This study compared the effects of HIIT under hypoxic conditions on cardiometabolic function with that under normoxia in overweight Chinese young women. Methods: A double-blind randomized controlled experimental design was applied. Twenty-four sedentary overweight Chinese young women (weight: 68.8  7.0 kg, BMI: 25.8  2.3 kg∙m-2) participated in the HIIT under either normoxia (NORM, n = 13, PIO2: 150 mmHg, FIO2: 0.21) or normobaric hypoxia (HYP, n = 11, PIO2: 117 mmHg, FIO2: 0.15) for five weeks. HIIT was composed of 60 repetitions of 8 s maximal cycling effort interspersed with 12-s recovery per day, for four days per week. Cardiorespiratory fitness [peak oxygen uptake (VO2peak), and peak oxygen pulse (peak O2 pulse)], serum lipid profile [triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)], and body composition (regional and whole-body), were assessed at pre- and post-intervention during the days beyond the self-reported menstrual phase of the participants. Habitual physical activity and diary behavior were maintained during the intervention period. Results: With similar daily energy intake and physical activity, the increases in VO2peak [NORM: 0.26  0.37 Lmin-1 (+11.8%) vs. HYP: 0.54  0.34 Lmin-1 (+26.1%)] and peak O2 pulse (NORM: +13.4% vs. HYP: +25.9%) for HYP were twice-larger than for NORM (p < 0.05). Although the 5-wk HIIT led to significant improvements in the ratios of TC/HDL-C (p = 0.035) and TG/HDL-C (p = 0.027), no significant group effects were found on the serum variables. Further, no significant changes in body composition or serum fasting leptin were observed in either group. Conclusion: 5-wk of HIIT improved cardiorespiratory fitness and blood lipids in overweight Chinese young females, while the additive effect of the HIIT under normobaric hypoxia solely enhanced cardiorespiratory fitness, but not body composition or serum lipid profile.

This study compared the effects of a single bout of resistance exercise (RES) on glycemic homeostasis to isotime sprint interval exercise (SIE) using a within-subjects design. Nineteen nondiabetic males (age:23.3±0.7 yrs; height:173.1±1.2 cm; weight:79.1±4.8 kg; % fat:22.5±2.5%) were studied. RES involved nine exercises of 10 repetitions at 75% 1-RM using a 2 : 2 s tempo and was interspersed with a one-minute recovery; SIE involved four 30 s’ all-out cycling effort interspersed with four minutes of active recovery. Plasma glucose and insulin in response to a 75 g oral glucose tolerance test were assessed 12 h after exercise. In comparison to a no exercise control trial (CON), the area under curve (AUC) of plasma glucose was reduced with both RES and SIE (P<0.05), while insulin AUC was only reduced with RES. Cederholm, Gutt, Matsuda, and HOMA indices were improved (P<0.05) following RES compared to CON. Corresponding changes following SIE were only found in Cederholm and Gutt indices (P<0.05). No difference was found in plasma variables and indices between RES and SIE (P>0.05). Such findings suggest that the RES may represent a potential alternative to the SIE in the development of time-efficient lifestyle intervention strategies for improving diabetes risk factors in healthy populations.

Early childhood education and care (ECEC) scholars and health professionals worldwide share a common concern about the decline in children's physical development and activity due to lack of access to good quality outdoor environments. Early childhood education and care facilities across the world have been affected by trends that are limiting outdoor play, including large-scale migration of rural populations to industrial urban areas where access to the outdoors is limited. In China, this migration and other factors have resulted in dramatic changes to the nation's sociocultural fabric. The authors discuss policies and practices regarding outdoor play designed for millennial preschoolers in China. It presents a Chinese perspective on preschoolers' (3- to 6-year-olds) outdoor play and physical activity and provides recommendations to enhance a worldwide view of child development in the new millennium.

Purpose: To examine the effect of acute moderate-intensity continuous exercise performed under normobaric severe hypoxia on cognition, compared to sea-level normoxia. Methods: Thirty healthy inactive women randomly performed two experimental trials separated by at least three days but at approximately the same time of day. Executive functions were measured during the follicular stage via an interference control task before (rest) and during exercise with 45% peak power output under normobaric normoxia (PIO2 = 150 mmHg, FIO2 = 0.21), and (2) hypoxia (PIO2 = 87 mmHg, FIO2 = 0.12, simulated at an altitude of 4000 m). Reaction time (RT), accuracy rate (AC), heart rate, ratings of perceived exertion, and peripheral oxygen saturation (SpO2) were collected before and during exercise. Results: RT (p &lt, 0.05, &eta, 2p = 0.203) decreased during moderate exercise when compared at rest, while a short bout of severe hypoxia improved RT (p &lt, 2p = 0.134). Exercise and hypoxia had no effects on AC (p &gt, 0.05). No significant associations were found between the changes of RT and SpO2 under the conditions of normoxia and hypoxia (p &gt, 0.05). Conclusions: At the same phase of the menstrual cycle, a short bout of severe hypoxia simulated at 4000 m altitude caused no impairment at rest. RT during moderate exercise ameliorated in normoxia and severe hypoxia, suggesting that both exercise and short-term severe hypoxia have benefits on cognitive function in sedentary young women.

Background and Objectives: Limited research has evaluated the effects of acute exercise on cognition under different conditions of inspired oxygenation. Thus, the purpose of this study was to examine the effects of high-intensity interval exercise (HIE) under normoxia (inspired fraction of oxygen (FIO2): 0.209) and moderate hypoxia (FIO2: 0.154) on cognitive function. Design: A single-blinded cross-over design was used to observe the main effects of exercise and oxygen level, and interaction effects on cognitive task performance. Methods: Twenty inactive adults (10 males and 10 females, 19&ndash, 27 years old) performed a cognitive task (i.e., the Go/No-Go task) before and immediately after an acute bout of HIE under normoxic and hypoxic conditions. The HIE comprised 10 repetitions of 6 s high-intensity cycling against 7.5% body weight interspersed with 30 s passive recovery. Heart rate, peripheral oxygen saturation (SpO2) and rating of perceived exertion were monitored. Results: The acute bout of HIE did not affect the reaction time (p = 0.204, &eta, 2 = 0.083) but the accuracy rate decreased significantly after HIE under both normoxic and hypoxic conditions (p = 0.001, &eta, 2 = 0.467). Moreover, moderate hypoxia had no influence either on reaction time (p = 0.782, &eta, 2 = 0.004) or response accuracy (p = 0.972, &eta, 2 &lt, 0.001). Conclusions: These results indicate that an acute session of HIE may impair response accuracy immediately post-HIE, without sacrificing reaction time. Meanwhile moderate hypoxia was found to have no adverse effect on cognitive function in inactive young adults, at least in the present study.

Intermittent normobaric hypoxia training, an alternative to altitude training for athletes, may be beneficial to treat overweight and obesity. The purpose of this study is to investigate whether normobaric hypoxia training combined with low-caloric diet has the additive effect on weight loss compared with normoxia training in obese young adults. Twenty-two subjects (age 17–25 years, body mass index >27.5 kg/m2) were recruited for a 4-week residential camp of weight loss with low caloric intake, and trained at 60–70 % maximal heart rate of aerobics and 40–50 % of maximal strength of training. They were randomly assigned to either a normobaric hypoxia (HT, FiO2 = 16.4–14.5 %) or normoxia training group (NT, FiO2 = 21 %), and subjects in HT and NT groups experienced weekly 16-h normoxia and 6-h hypoxia or 22-h normoxia training, respectively. Body composition, resting blood pressure (BP) and brachial-ankle pulse wave velocity (baPWV) were determined before and after the intervention. Weight loss was found in HT (−6.9 kg or −7.0 %, p

This study was to determine the effects of five-week high-intensity interval training (HIIT) on cardiorespiratory fitness, body composition, blood glucose, and relevant systemic hormones when compared to moderate-intensity continuous training (MICT) in overweight and obese young women.Methods. Eighteen subjects completed 20 sessions of HIIT or MICT for five weeks. HIIT involved 60 × 8 s cycling at ~90% of peak oxygen consumption (V˙O2peak) interspersed with 12 s recovery, whereas MICT involved 40-minute continuous cycling at 65% ofV˙O2peak.V˙O2peak, body composition, blood glucose, and fasting serum hormones, including leptin, growth hormone, testosterone, cortisol, and fibroblast growth factor 21, were measured before and after training.Results. Both exercise groups achieved significant improvements inV˙O2peak(+7.9% in HIIT versus +11.7% in MICT) and peak power output (+13.8% in HIIT versus +21.9% in MICT) despite no training effects on body composition or the relevant systemic hormones. Blood glucose tended to be decreased after the intervention (p=0.062). The rating of perceived exertion in MICT was higher than that in HIIT (p=0.042).Conclusion. Compared with MICT, short-term HIIT is more time-efficient and is perceived as being easier for improving cardiorespiratory fitness and fasting blood glucose for overweight and obese young women.

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 ([Formula: see text]O2peak), both for four days in a week. Outcomes such as [Formula: see text]O2peak, 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, [Formula: see text]O2peak 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.

This study investigated the acute changes in glycemic homeostasis in response to brief, high-intensity, intermittent exercise in obese adults. Ten obese adults (age: 25.3±5.1 years; body mass index: 32.0±4.0) volunteered to participate in the study. The time-course changes in blood glucose in response to a 75-g oral glucose tolerance test were examined following: high-intensity intermittent exercise (HIE) of four 30-second all-out cycling efforts interspersed with 4-minute active recovery periods; 24 hours of recovery post-HIE (REC); and no treatment (control, CON). Blood glucose in each trial was measured before, and 30, 60, 90, and 120 minutes after glucose intake (GI). Blood glucose (mmol/L) at 30 minutes post-GI in the HIE (6.9±0.4) trial was significantly lower (p0.05). This study demonstrated the improvement in glycemic homeostasis in obese adults immediately after brief, high-intensity, intermittent exercise. These effects were maintained for at least 24 hours postexercise. The findings may be useful in the development of time-efficient lifestyle intervention strategies for improving obesity-related risk factors for diabetes.

This field study investigated the influences of exposure to natural low altitude on endurance training-induced alterations of redox homeostasis in professional adolescent runners undergoing 12-week off-season conditioning program at an altitude of 1700 m (Alt), by comparison with that of their counterparts completing the program at sea-level (SL). For age-, gender-, and Tanner-stage-matched comparison, 26 runners (n=13in each group) were selected and studied. Following the conditioning program, unaltered serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (T-AOC), and superoxide dismutase accompanied with an increase in oxidized glutathione (GSSG) and decreases of xanthine oxidase, reduced glutathione (GSH), and GSH/GSSG ratio were observed in both Alt and SL groups. Serum glutathione peroxidase and catalase did not change in SL, whereas these enzymes, respectively, decreased and increased in Alt. Uric acid (UA) decreased in SL and increased in Alt. Moreover, the decreases in GSH and GSH/GSSG ratio in Alt were relatively lower compared to those in SL. Further, significant interindividual correlations were found between changes in catalase and TBARS, as well as between UA and T-AOC. These findings suggest that long-term training at natural low altitude is unlikely to cause retained oxidative stress in professional adolescent runners.

We thank Gonzalez-Muniesa et al. for their comments on our article, which could be seen as evidence for the hypothesis that hypoxia can be used as a tool to treat obesity and associated comorbidities. Despite the fact that hypoxia training resulted in more weight loss than normoxia training in our study, the contributions of nutrition, hypoxia, and physical activity to weight loss are still unknown and thus more well-controlled studies are needed in this area. Over the last two decades, new techniques to simulate hypoxia training, typically referred to as living high/training low (LHTL) and intermittent hypoxic training (IHT), have been studied extensively; it is generally agreed that they are valid methods for improving cardiovascular capacity and sports performance [1]. In a Chinese study with a design that was similar to ours, Wang et al. (2013) [2] found that obese adolescents with a controlled caloric intake of up to 2,000 kcal/day in a residential camp who performed endurance exercise at 60–80% of the maximum heart rate for 24 h a week (2 h per session, two sessions per day, 6 days per week) for 4 weeks had greater weight loss when living in normobaric hypoxia conditions equivalent to 2,700 m altitude for 10 h per day (LHTL) compared to living and training at sea level (living low/training low, LLTL). However, no significant additive effects were found for weight loss (−9.3 % for LHTL and −8.0 % for LLTL) or fat loss (−14.1 % for LHTL and −14.4 % for LLTL) or for metabolic improvements. Moreover, the rate of muscle mass reduction was 2.9 % for LHTL and less than 1.0 % for LLTL. The reason for the unexpected results with respect to weight loss might be the pattern of constant hypoxia, which did not reach the level of an altitude/hypoxic dose–response effect; in addition, good acclimatization to hypoxia limits the use of altitude or hypoxia to treat obesity [3, 4]. In agreement with a previously published statement that referred to the dual role of hypoxia in the pathogenesis and therapy of obesity [3], it is obviously essential to maximize the strengths and minimize the weaknesses of hypoxia exposure and/or training in treating overweight and obesity. Controllable nonadjustment to hypoxia exposure at a range of 2,000–3,000 m (fraction of inspired oxygen=16.4–14.5 %) should be considered as a critical factor of a therapeutic hypoxia paradigm. Moreover, combining aerobic and resistance training seems to be helpful in protecting against excessive muscle loss during exposure to hypoxia. From the perspective of applicability, it is imperative to increase our knowledge of and to develop practical methods for using hypoxia as a therapeutic approach to preventing and treating obesity in different populations. The research team led by Marinez has carried out a substantial amount of work on the etiology of obesity and strategies for combating obesity and related risk factors. We look forward to hearing about their new research findings soon.

LANGUAGE NOTE | Document text in Chinese; abstract also in English.The changes of serum hormones during strenuous exercise were studied. 40 female Sprague-Dawley rats were randomly assigned into two groups— the exhaustive swimming group rats and the control. They were sacrificed after exhaustive swimming. Changes in the exercised rats indicated that: 1) the concentrations of serum estradiol (雌二醇, E2) decreased significantly, 2) no significant change in progesterone (孕酮, P, 3) the level of serum cortisol (皮質酵, C)was higher in the exercised rats, 4) the testosterone (睾酮, T) level remained unchanged in both groups, 5) triiodothyronine (二碘甲狀腺胺酸,T3) and thyroxine (四碘甲狀腺胺酸, T4) levels were lower than those of the control group. It appears the changes of serum E2 and P are related to adrenal and thyroid functions and they in turn affect the ovary indirectly.本文章利用40只大白鼠探討有關在力竭性游泳後血清激素的變化。研究員把大白鼠分成實驗組和對照組，經測試後分析其結果及作出討論。

This study investigated the 1-year longitudinal effect of professional training in adolescent runners on redox balance during intense endurance exercise. Changes in selected serum oxidant and antioxidant status in response to a 21-km running time trial in 10 runners (15.5 ± 1.3 years) undergoing professional training were evaluated twice in 12 months (pre- and post-evaluation). Venous blood samples were collected immediately before and 4-h following the 21-km run for analysis of serum concentrations of thiobarbituric acid-reactive substances (TBARS), xanthine oxidase (XO), catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC). In pre-evaluation trial, serum TBARS and SOD decreased after the 21-km run (p < 0.05) while XO, GSH, CAT and TAOC were unchanged. In post-evaluation trial, serum TBARS and SOD decreased, whereas XO and CAT increased post-exercise (p < 0.05). Furthermore, pre-exercise serum T-AOC, post-exercise serum XO, CAT, T-AOC (p < 0.05), and GSH (p = 0.057) appeared to be higher than the corresponding pre-evaluation values. The current findings suggest that a professional training regime in adolescent runners is not likely to jeopardize the development of their antioxidant defense. However, uncertainties in the maintenance of redox balance in runners facing increased exercise-induced oxidative stress as a consequence of training-induced enhancement of exercise capacity await further elucidation.

The purpose of this study was to investigate the acute effects of an all-out 100-m swimming sprint on changes in serum enzyme and calcium ion concentrations in young (12 to 14 years) male and female swimmers. Changes in serum enzyme concentrations of creatine kinase (CK), lactate dehydrogenase (LDH), glutamic pyruvate transaminase (GPT), glutamic oxaloacetate transaminase (GOT), serum glucose (GL), and calcium ion (Ca2+) concentrations were measured in 23 elite swimmers (13 boys and 10 girls) before and after a 100-m freestyle all-out sprint. Analysis showed (1) there were significant sex differences in serum CK concentration at baseline (Pretest); (2) significant sex differences in serum CK and LDH concentrations after the 100-m spring; (3) no significant differences in Ca2+ concentration after the 100-m spring; and (4) significant increase in Serum GOT and blood glucose concentrations after the 100-m sprint, suggesting chat these might both be useful indicators of anaerobic exercise stress in young swimmers.

PURPOSE: Exercise induces a cardioprotective effect referred to as "preconditioning". Whether the preconditioning impacts upon the cardiac troponin T (cTnT) response to subsequent exercise bouts is unclear. This study investigated the effects of an initial exercise bout, a second exercise bout 48 h later, as well as subsequent exercise every 48 h for 4 days or a single identical exercise bout after 8 days of inactivity gap on cTnT response to acute exercise. METHODS: Twenty-eight sedentary overweight young women were randomly assigned to either six bouts of exercise each separated by 48 h or three bouts of exercise with 48 h between the first two bouts and 8 days between the second and third bouts. All exercise bouts were identical (60% [Formula: see text], 200 kJ) and the total testing period (10 days) was the same for both groups. cTnT was assessed before and after the 1st, 2nd, and final exercise bouts. RESULTS: cTnT increased (129%, P 0.05) effect on post-exercise cTnT (

AIMS: This study characterized (1) the cardiac troponin T (cTnT) response to three forms of acute high-intensity interval exercise (HIE), and (2) the impact of 12 weeks of HIE training on the cTnT response to acute exercise in sedentary obese young women. METHODS: Thirty-six sedentary women were randomized to traditional HIE training (repeated 4-min cycling at 90% V̇O2max interspersed with 3-min rest, 200 kJ/session), work-equivalent sprint interval exercise (SIE) training (repeated 1-min cycling at 120% V̇O2max interspersed with 1.5-min rest) or repeated sprint exercise (RSE) training (40 × 6-s all-out sprints interspersed with 9-s rest) group. cTnT was assessed using a high sensitivity assay before and immediately, 3 and 4 h after the 1st (PRE), 6th (EARLY), 20th (MID), and 44th (END) training session, respectively. RESULTS: cTnT was elevated (P < 0.05) after all forms of acute interval exercise at the PRE and EARLY assessment with cTnT response higher (P < 0.05) after HIE (307%) and SIE (318%) than RSE (142%) at the PRE assessment. All forms of acute interval exercise at MID and END had no effect on the cohort cTnT concentration post-exercise (all P > 0.05). CONCLUSION: For sedentary obese young women, both HIE and SIE, matched for total work, induced a similar elevation in cTnT after acute exercise with a smaller rise observed after RSE. By the 44th training session, almost no post-exercise cTnT elevation was observed in all three groups. Such information is relevant for clinicians as it could improve medical decision-making. This article is protected by copyright. All rights reserved.

CONTEXT: Post-exercise cardiac troponin release has been extensively described in athletic groups but little attention has been given to any role of sex in mediating this phenomenon. OBJECTIVE: We compared the release of cardiac troponin T (cTnT) after endurance running in training-experience, biological-age and maturity-matched young male and female runners. MATERIALS AND METHODS: Nineteen male (training history: 2.3 ± 1.0 years; mean age: 16.1 ± 1.2 years; Tanner stage: 3.7 ± 0.6) and 19 female (training history: 2.2 ± 1.0 years; mean age: 15.9 ± 1.4 years; Tanner stage: 4.0 ± 0.4) runners performed a 21 km run with "all-out" effort. Serum cTnT levels were assessed at pre-exercise (Pre-ex) and at 4 h post-exercise (Post-ex). RESULTS: At Pre-ex, cTnT concentrations were below the 99th percentile value (10 ng.l(-1)) in 32/38 runners. Post-ex cTnT increased in all subjects but the response was substantially higher (p