RESUMO
BACKGROUND: Circulating miRNAs (c-miR) have been shown to be potential biomarkers in sarcopenia, but the miRNAs response to aerobic exercise in older people remains inconclusive. We sought to examine the exercise benefits on physical fitness and miRNAs, and to explore the mediating effect of miRNAs on training-induced fitness changes. METHODS: This controlled trial recruited 58 community-dwelling older adults and randomized them into exercise group (EX) and control group (CON). EX received 8-week supervised moderate intensity cycling training 3x/week. C-miR expression (c-miR-21, c-miR-126, c-miR-146a, c-miR-222), physical fitness (body composition, cardiorespiratory fitness, muscular fitness) and physical activity level (PAL, measured as in daily step counts) were evaluated at baseline, post-training, and post-16-week follow-up. The mediating effect of miRNA expression onto exercise-induced physical fitness change was determined by causal mediation analysis (CMA). RESULTS: Exercise significantly improved body fat and cardiorespiratory fitness in older people while maintaining muscle mass and strength, and augmented expression of c-miR-126, c-miR-146a, and c-miR-222 for up to 16 weeks post-training. Notably, older people in EX had substantially higher daily step counts than CON throughout the study even after the active training period. However, CMA revealed no significant indirect effect but a potential mediating effect of c-miR-21, but not the rest, onto the body composition, cardiorespiratory fitness, and lower limb strength. CONCLUSION: An eight-week supervised MICT program promoted a higher level of physical activity up to 16 weeks post-training, which induces better cardiorespiratory fitness and resists decline in muscular measures. C-miRNA, especially c-miR-21, potentially mediates the training effect upon fitness.
Assuntos
MicroRNA Circulante , Exercício Físico , Vida Independente , Aptidão Física , Humanos , Idoso , Masculino , Aptidão Física/fisiologia , Feminino , Exercício Físico/fisiologia , Seguimentos , MicroRNA Circulante/sangue , Idoso de 80 Anos ou maisRESUMO
Mitochondria dysfunction is implicated in the pathogenesis of cardiovascular diseases (CVD). Exercise training is potentially an effective non-pharmacological strategy to restore mitochondrial health in CVD. However, how exercise modifies mitochondrial functionality is inconclusive. We conducted a systematic review using the PubMed; Scopus and Web of Science databases to investigate the effect of exercise training on mitochondrial function in CVD patients. Search terms included "mitochondria", "exercise", "aerobic capacity", and "cardiovascular disease" in varied combination. The search yielded 821 records for abstract screening, of which 20 articles met the inclusion criteria. We summarized the effect of exercise training on mitochondrial morphology, biogenesis, dynamics, oxidative capacity, antioxidant capacity, and quality. Amongst these parameters, only oxidative capacity was suitable for a meta-analysis, which demonstrated a significant effect size of exercise in improving mitochondrial oxidative capacity in CVD patients (SMD = 4.78; CI = 2.99 to 6.57; p < 0.01), but with high heterogeneity among the studies (I2 = 75%, p = 0.003). Notably, aerobic exercise enhanced succinate-involved oxidative phosphorylation. The majority of the results suggested that exercise improves morphology and biogenesis, whereas findings on dynamic, antioxidant capacity, and quality, were inadequate or inconclusive. A further randomized controlled trial is clearly required to explain how exercise modifies the pathway of mitochondrial quantity and quality in CVD patients.
Assuntos
Antioxidantes , Doenças Cardiovasculares , Humanos , Exercício Físico , Doenças Cardiovasculares/terapia , Mitocôndrias , SuccinatosRESUMO
BACKGROUND: Tai Chi (TC) is a Chinese mind-body exercise with proven physical and psychological benefits. A modified TC via virtual reality (VR) may be suitable for the elderly owing to the immediate guidance and feedback regarding movement accuracy. This study explored the cognitive and physical effects of a VR-based TC (VRTC) exercise program on older adults with cognitive impairment (CI). METHODS: Sixty older adults with CI were cluster-assigned to either the VRTC or the control group; the intervention was conducted twice weekly for 6 months. Outcomes included cognitive and physical functions. The movement accuracy score and attendance were recorded. Generalized estimating equation (GEE) and multiple regression analyses were performed. RESULTS: Adjusted GEE analysis showed significant interaction effects in the 6-min walk test, 30-s sit-to-stand test, functional reach, 5-m gait speed, and abstract thinking and judgment. Overall, medium to large effect sizes (d = 0.50-0.82) were found in favor of the VRTC group. The average movement accuracy score in the first 3 months significantly predicted improvement in cognitive performance (p = 0.011). CONCLUSIONS: The VRTC exercise posed a protective effect for some cognitive and physical functions in older adults with CI. The more engaging the program, the greater the improvement in the cognitive performance.
Assuntos
Cognição/fisiologia , Disfunção Cognitiva , Tai Chi Chuan , Realidade Virtual , Idoso , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Disfunção Cognitiva/terapia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Feminino , Humanos , Masculino , Desempenho Físico Funcional , Tai Chi Chuan/métodos , Tai Chi Chuan/psicologia , Taiwan , Resultado do TratamentoRESUMO
PURPOSE: Excellent vision is essential to performing well in sports. Sports vision includes visual, perceptual, cognitive, and oculomotor tasks that enable athletes to process and respond to what is seen. We aimed to examined how sports vision parameters - dynamic visual acuity (DVA), eye movement (EM), peripheral vision (PV), and momentary vision (MV) - varied with age and sex and assessed how static visual acuity (SVA) affect sports vision performance. MATERIALS AND METHODS: Sports vision was assessed at 45 cm distance at best-corrected SVA in 310 nonathletic participants (age, 6-60 years). Among these 310 participants, 108 university students underwent their sports vision test at 45 cm and 2.5 m distance, with and without glasses. The 4 sports vision parameters were measured by Athlevision software package installed to a laptop. Two-way analysis of variance (ANOVA) was used to compare sports vision performance in relation to age group and sex. Repeated-measures ANOVA with 1 within-factor (4 conditions) were used to analyze how sports vision varied among the near/far distance with/without glasses conditions. RESULTS: DVA increased during childhood, peaked during the 20s or 30s, and gradually decreased during middle age (P < 0.0001). DVA was significantly better in males than in females (P = 0.0001). The other 3 sport vision parameters - EM, PV, and MV - exhibited similar age trends (P < 0.001) but did not differ between two sexes. The university students with mild myopia had similar DVA, EM, and PV at both near and far distances, with and without correction; but moderate or severe myopic students with uncorrected vision had worse DVA, EM, and PV at 2.5 m than at 45 cm. CONCLUSION: Low SVA in uncorrected myopia significantly interferes the performance in sport vision tests applied in this study, especially in far distance. Improve static vision, such as myopic correction, may significantly improve sports vision, which is important in athletic performance and safety.
RESUMO
Table tennis athletes and non-athletes potentially differ in stereopsis and eye-hand response times (RT), but whether stereopsis correlates with response time has scarcely been discussed. We aimed to compare stereopsis and RT between collegiate table tennis athletes and non-athletes and to examine the correlation between stereopsis and RT. From December 2016 to October 2019, table tennis athletes (n = 80) and non-athletes (n = 56) were recruited. Stereopsis was measured in four modes (A25, A50, R25, R50: approaching and receding directions at 25 mm/s or 50 mm/s). RT was measured with simple and choice tasks at zero, shoulder, and random distance. For stereopsis, the judged deviations were smaller during the approaching phases. Men had smaller A25 than women (p =0.012), whereas table tennis athletes showed smaller R25 and A50 than non-athletes (p = 0.03, 0.01, respectively). RT increased from simple to choice conditions and from zero to random, followed by shoulder distance. Men were significantly faster than women in choice tasks (p < 0.01). Table tennis athletes performed better in RT than the non-athletes (p < 0.05). No correlation was observed between stereopsis and RT (r = -0.01 to 0.12). In conclusion, athletes from table tennis sports showed better stereopsis and RT than non-athletes. Men had better stereopsis and RT than women. There was no correlation between stereopsis and RT.
Assuntos
Tênis , Atletas , Percepção de Profundidade , Feminino , Mãos , Humanos , Masculino , Tempo de ReaçãoRESUMO
Objectives: It is unclear whether poor health is a contributing factor or a consequence of burn-out. We aimed to explore the relationship among job stress, physical health, mental health, burnout, and coping strategies among health professionals using a moderated mediation model. Methods: Health professionals in Taiwan were invited using a stratified and probability proportional to size sampling. A structure equation model (SEM) was used to examine relationships among job stress, burnout, and physical/mental health. The bootstrapping approach for moderated mediation analysis was then used to explore the role of coping strategies. Results: Totally 935 health professionals participated. The SEM model revealed that job stress was inversely associated with physical and mental health. The direct association between job stress and burn-out was insignificant. Moderated mediation analysis revealed that job stress influenced burnout through physical health and mental health, and that the coping strategy of support-seeking moderated the indirect effect only through mental health. Conclusions: Support-seeking is a good coping strategy for health professionals to buffer the harmful effects of job stress on mental health.
Assuntos
Esgotamento Profissional , Pessoal de Saúde/psicologia , Estresse Ocupacional , Adaptação Psicológica , Humanos , Satisfação no Emprego , Saúde Mental , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Response time (RT) is crucial in karate athletes and can be trained. The aim of this study was to compare standing eye-hand RT and contest performance in nonelite karate athletes who underwent 6 weeks of training using either a stationary preprogrammed target dummy (experimental group) or traditional karate instruction (control group). METHODS: Forty male nonelite karate athletes (20 in each group) were recruited. Standing RT and contest performance was assessed before and after training. Attack RT (eye-hand or eye-leg) and success rate were measured in the experimental group only during training. RESULTS: Age, years of karate practice, Body Mass Index, and standing RT before training did not significantly differ between groups. In the control group, standing RT was significantly improved in the dominant hand after training (25.62±24.18 ms, P=0.0003), but there was no significant improvement in standing RT of the nondominant hand and karate contest score. In the experimental group, standing RT was significantly faster after training (improvement in dominant hand: 69.84±50.85 ms, P<0.0001; improvement in nondominant hand: 68.94±59.43 ms, P<0.0001), and the karate contest score was significantly improved (P=0.0234). During the training period, mean attack RT improved from 1047.4 ms in week1 to 944.9 ms in week6 (P<0.001). However, the success rate gradually decreased from 89.3% (week 1) to 62.4% (week 6) (P<0.001). CONCLUSIONS: A 6-week training using a stationary preprogrammed target dummy improved contest performance and standing RT in both the dominant and nondominant hands of nonelite karate athletes. Improvements of RT in the dominant hand were also seen in the control group.