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1.
Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.  相似文献   

2.
BackgroundWe examined the associations of cardiorespiratory fitness (CRF) and white blood cell count (WBC) with mortality outcomes.MethodsA total of 52,056 apparently healthy adults completed a comprehensive health examination, including a maximal treadmill test and blood chemistry analyses. CRF was categorized as high, moderate, or low by age and sex; WBC was categorized as sex-specific quartiles.ResultsDuring 17.8 ± 9.5 years (mean ± SD) of follow-up, a total of 4088 deaths occurred. When regressed jointly, significantly decreased all-cause mortality across CRF categories was observed within each quartile of WBC in men. Within WBC Quartile 1, all-cause mortality hazard ratios (HRs) with a 95% confidence interval (95%CI) were 1.0 (referent), 1.29 (95%CI: 1.06?1.57), and 2.03 (95%CI: 1.42?2.92) for high, moderate, and low CRF categories, respectively (p for trend < 0.001). Similar trends were observed in the remaining 3 quartiles. With the exception of cardiovascular disease (CVD) mortality within Quartile 1 (p for trend = 0.743), there were also similar trends across CRF categories within WBC quartiles in men for both CVD and cancer mortality (p for trend < 0.01 for all). For women, there were no significant trends across CRF categories for mortality outcomes within Quartiles 1–3. However, we observed significantly decreased all-cause mortality across CRF categories within WBC Quartile 4 (HR = 1.05 (95%CI: 0.76?1.44), HR = 1.63 (95%CI:1.20?2.21), and HR = 1.87 (95%CI:1.29?2.69) for high, moderate, and low CRF, respectively (p for trend = 0.002)). Similar trends in women were observed for CVD and cancer mortality within WBC Quartile 4 only.ConclusionThere are strong joint associations between CRF, WBC, and all-cause, CVD, and cancer mortality in men; these associations are less consistent in women.  相似文献   

3.
PurposeThis study aimed to describe the national prevalence of Chinese children and adolescents who met the World Health Organization muscle-strengthening exercise (MSE) recommendations and identify correlates of meeting the MSE recommendations.MethodsCross-sectional data from the 2019 Physical Activity and Fitness in China—The Youth Study, a nationally representative sample of Chinese children and adolescents (n = 80,413; mean age = 13.7 years; 53.9% girls) and their parents, were analyzed. Children and adolescents who reported engaging ≥3 days (up to 7 days) of MSE per week were classified as meeting the MSE recommendations. MSE, demographics, lifestyle behaviors (sport participation, moderate-to-vigorous physical activity, screen time, and sleep duration), exercise intention, peer and parental support, and parental MSE participation were assessed through self-reports. Logistic regression models were used to determine the correlates of meeting the MSE recommendations. The analyses were completed in 2020.ResultsOverall, 39.3% of children and adolescents met the MSE recommendations. Girls, 10th–12th graders, minorities, those from lower income households and those from families with lower parental education were less likely to meet the MSE recommendations. Children and adolescents who were proficient in ≥2 sports were more likely to meet the MSE recommendations (adjusted odds ratio (aOR) = 1.44, 95% confidence interval (95%CI): 1.26–1.65), as were those with more moderate-to-vigorous physical activity (aOR = 1.57, 95%CI: 1.53–1.61). Additionally, children and adolescents with high exercise intention (aOR = 1.60, 95%CI: 1.51–1.69), those whose parents met the adult MSE recommendations (aOR = 1.46, 95%CI: 1.40–1.52), and those who received high peer (aOR = 1.27, 95%CI: 1.20–1.34) and parental support (aOR = 1.07, 95%CI: 1.04–1.12) were more likely to meet the MSE recommendations.ConclusionLess than two-fifths of Chinese children and adolescents met the World Health Organization MSE recommendations. The correlates identified in our study can help inform the development of school and community based strategies and policies to enhance participation in MSE and improve muscular fitness of all Chinese children and adolescents.  相似文献   

4.
BackgroundBoth hypertension and grip strength (GS) are predictors of mortality and cardiovascular disease (CVD), but whether these risk factors interact to affect CVD and all-cause mortality is unknown. This study sought to investigate the associations of GS with the risk of major CVD incidence, CVD mortality, and all-cause mortality in patients with hypertension.MethodsGS was measured using a Jamar dynamometer (Sammons Preston, Bolingbrook, IL, USA) in participants aged 35–70 years from 12 provinces included in the Prospective Urban Rural Epidemiology China Study. Cox frailty proportional hazards models were used to examine the associations of GS and hypertension and the outcomes of all-cause mortality and CVD incidence/mortality.ResultsAmong 39,862 participants included in this study, 15,964 reported having hypertension, and 9095 had high GS at baseline. After a median follow-up of 8.9 years (interquartile range, 6.7–9.9 years), 1822 participants developed major CVD, and 1250 deaths occurred (388 as a result of CVD). Compared with normotensive participants with high GS, hypertensive patients with high GS had a higher risk of major CVD incidence (hazard ratio (HR) = 2.39; 95% confidence interval (95%CI): 1.86–3.06; p < 0.001) or CVD mortality (HR = 3.11; 95%CI: 1.59–6.06; p < 0.001) but did not have a significantly increased risk of all-cause mortality (HR = 1.24; 95%CI: 0.92–1.68; p = 0.159). These risks were further increased if hypertensive participants whose GS level was low (major CVD incidence, HR = 3.31, 95%CI: 2.60–4.22, p < 0.001; CVD mortality, HR = 4.99, 95%CI: 2.64–9.43, p < 0.001; and all-cause mortality, HR = 1.93, 95%CI: 1.47–2.53, p < 0.001).ConclusionThe present study demonstrates that low GS is associated with the highest risk of major CVD incidence, CVD mortality, and all-cause mortality among hypertensive patients. High levels of GS appear to mitigate long-term mortality risk among hypertensive patients.  相似文献   

5.
PurposeThe aim of the present study was to determine the association between adherence to the 24-h movement guidelines during middle adolescence and glucose outcomes (glycated hemoglobin and fasting glucose) and type 2 diabetes mellitus (T2DM) in adulthood, 14 and 22 years later.MethodsWe analyzed data from apparently healthy adolescents aged 12–18 years who participated in Waves I and II (1994–1996, n = 14,738), Wave IV (2008–2009, n = 8913), and Wave V (2016–2018, n = 3457) of the National Longitudinal Study of Adolescent to Adult Health (Add Health) in the United States. Physical activity, screen time, and sleep duration were measured using questionnaires, and the 24-h guidelines were defined as: 5 or more times moderate-to-vigorous physical activity per week, ≤2 h per day of screen time, and 9–11 h of sleep for 12–13 years and 8–10 h for 14–17 years. Capillary and venous whole blood was collected and analyzed to determine glycated hemoglobin and fasting glucose for Waves IV and V, respectively.ResultsOnly 2.1% of the adolescents met all the 3 guidelines, and 37.8% met none of them. In both waves IV and V, adolescents who met physical activity and screen time guidelines had lower odds of T2DM in adulthood than those who did not meet any of these guidelines (Wave IV; prevalence ratio (PR) = 0.57, 95% confidence interval (95%CI): 0.21–0.89; Wave V: PR = 0.43, 95%CI: 0.32–0.74). Only for Wave V did adolescents who met all 3 guidelines have lower odds of T2DM at follow-up compared with those who did not meet any of these guidelines (PR = 0.47, 95%CI: 0.24–0.91). Also, for each increase in meeting one of the 24-h recommendations, the odds of T2DM decreased by 18% (PR = 0.82, 95%CI: 0.61–0.99) and 15% (PR = 0.85, 95%CI: 0.65–0.98) in adulthood for Waves IV and V, respectively.ConclusionPromoting all 24-h movement guidelines in adolescence, especially physical activity and screen time, is important for lowering the potential risk of T2DM in adulthood.  相似文献   

6.
BackgroundThis study examined the joint associations of sleep patterns and physical activity (PA) with all-cause, cardiovascular disease (CVD), and cancer mortality.MethodsA total of 341,248 adults (mean age = 39.7 years; men: 48.3%) were included in the study, with a 15-year follow-up. Participants reported sleep duration and disturbances (difficulty falling asleep, easily awakened, or use of sleeping medication). PA was classified into 4 levels: <7.5, 7.5–14.9, 15.0–29.9, and ≥30.0 metabolic equivalent hours per week (MET-h/week). To understand the joint associations of sleep patterns and PA with mortality, Cox proportional hazard models were conducted, with exposure variables combining sleep duration/disturbances and PA.ResultsCompared with the reference group (sleeping 6–8 h/day), individuals who slept >8 h/day had higher risk for all-cause mortality (hazard ratio (HR) = 1.307, 95% confidence interval (95%CI): 1.248–1.369), CVD mortality (HR = 1.298, 95%CI: 1.165–1.445), and cancer mortality (HR = 1.128, 95%CI: 1.042–1.220). Short sleep duration was not associated with mortality risk. Increased risk of all-cause and CVD mortality was found in participants who had difficulty falling asleep (HR = 1.120, 95%CI: 1.068–1.175; HR = 1.163, 95%CI: 1.038–1.304, respectively), and used sleeping medication (HR = 1.261, 95%CI: 1.159–1.372; HR = 1.335, 95%CI: 1.102–1.618, respectively) compared with those who slept well. Long sleep duration and sleep disturbances were not associated with risk of all-cause and CVD mortality among individuals achieving a PA level of ≥15 MET-h/week, and in particular among those achieving ≥30 MET-h/week.ConclusionLong sleep duration, difficulty falling asleep, and use of sleeping medication were related to a higher risk of death. Being physically active at a moderate intensity for 25–65 min/day eliminated these detrimental associations.  相似文献   

7.
ABSTRACT

We performed a randomized, controlled trial to analyse the effects of resistance training (RT) on cognitive and physical function among older adults. Fifty participants (mean age 67 years, ~60% woman) were randomly assigned to an RT program or a control group. Participants allocated to RT performed three sets of 10-15RM in nine exercises, three times per week, for 12-weeks. Control group did not perform any exercise. Variables included cognitive (global and executive function) and physical function (gait, mobility and strength) outcomes. At completion of the intervention, RT was shown to have significantly mitigated the drop in selective attention and conflict resolution performance (Stroop test: -494.6; 95%CI: -883.1; ?106.1) and promoted a significant improvement in working memory (digit span forward: -0.6; 95%CI: ?1.0; ?0.1 and forward minus backward: -0.9; 95% CI: ?1.6; ?0.2) and verbal fluency (animal naming: +1.4, 95%CI 0.3, 2.5). No significant between-group differences were observed for other cognitive outcomes. Regarding physical function, at completion of the intervention, the RT group demonstrated improved fast-pace gait performance (?0.3; 95% CI: ?0.6; ?0.0) and 1-RM (+21.4 kg; 95%CI: 16.6; 26.2). No significant between-group differences were observed for other mobility-related outcomes. In conclusion, RT improves cognitive and physical function of older adults.  相似文献   

8.
BackgroundInconsistent results have been reported in developed countries for relationships between sedentary behavior and cancer incidence and mortality, and evidence from the Chinese population is scarce. This study aimed to investigate such relationships in large Chinese population-based prospective cohorts and to explore the joint effect and interaction of sedentary behavior and moderate-to-vigorous physical activity (MVPA) on these relationships.MethodsWe included 95,319 Chinese adults without cancer from 3 large cohorts and assessed their sedentary behavior and physical activity with a unified questionnaire. Cancer incidence and mortality were confirmed by interviewing participants or their proxies and checking hospital records and death certificates. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) for cancer and mortality were estimated using Cox proportional hazards regression models.ResultsDuring 559,002 person-years of follow-up, 2388 cancer events, 1571 cancer deaths, and 4562 all-cause deaths were recorded. Sedentary behavior was associated with increased risk of developing cancer and deaths in a dose–response manner. The multivariable-adjusted HRs (95%CIs) were the following: HR = 1.16, 95%CI: 1.01‒1.33; HR = 1.24, 95%CI: 1.04‒1.48; and HR = 1.15, 95%CI: 1.04‒1.28 for cancer incidence, cancer mortality, and all-cause mortality, respectively, for those having ≥10 h/day of sedentary time compared with those having <6 h/day of sedentary time. Sedentary populations (≥10 h/day) developed cancer or died 4.09 years and 2.79 years earlier, respectively, at the index age of 50 years. Failure to achieve the recommended level of MVPA may further aggravate the adverse associations, with the highest cancer and mortality risks being observed among participants with both ≥10 h/day of sedentary time and <150 min/week of MVPA. Limitations of this study include the fact that physical activity information was obtained via questionnaire instead of objective measurement and that there were insufficient incident cases for the analysis of associations between sedentary behavior and site-specific cancers.ConclusionSedentary behavior was associated with an increased risk of cancer and all-cause mortality among Chinese adults, especially for those with ≥10 h/day of sedentary time. It is necessary to reduce sedentary time, in addition to increasing MVPA levels, for the prevention of cancer and premature death.  相似文献   

9.
PurposeThis study aimed to examine the effects of plyometric jump training (PJT) on lower-limb stiffness.MethodsSystematic searches were conducted in PubMed, Web of Science, and Scopus. Study participants included healthy males and females who undertook a PJT programme isolated from any other training type.ResultsThere was a small effect size (ES) of PJT on lower-limb stiffness (ES = 0.33, 95% confidence interval (95%CI): 0.07–0.60, z = 2.47, p = 0.01). Untrained individuals exhibited a larger ES (ES = 0.46, 95%CI: 0.08–0.84, p = 0.02) than trained individuals (ES = 0.15, 95%CI: ‒0.23 to 0.53, p = 0.45). Interventions lasting a greater number of weeks (>7 weeks) had a larger ES (ES = 0.47, 95%CI: 0.06–0.88, p = 0.03) than those lasting fewer weeks (ES = 0.22, 95%CI: ‒0.12 to 0.55, p = 0.20). Programmes with ≤2 sessions per week exhibited a larger ES (ES = 0.39, 95%CI: 0.01–0.77, p = 0.04) than programmes that incorporated >2 sessions per week (ES = 0.20, 95%CI: –0.10 to 0.50, p = 0.18). Programmes with <250 jumps per week (ES = 0.50, 95%CI: 0.02–0.97, p = 0.04) showed a larger effect than programmes with 250–500 jumps per week (ES = 0.36, 95%CI: 0.00–0.72, p = 0.05). Programmes with >500 jumps per week had negative effects (ES = –0.22, 95%CI: –1.10 to 0.67, p = 0.63). Programmes with >7.5 jumps per set showed larger effect sizes (ES = 0.55, 95%CI: 0.02–1.08, p = 0.04) than those with <7.5 jumps per set (ES = 0.32, 95%CI: 0.01–0.62, p = 0.04).ConclusionPJT enhances lower-body stiffness, which can be optimised with lower volumes (<250 jumps per week) over a relatively long period of time (>7 weeks).  相似文献   

10.
BackgroundWeight-loss-induced fat loss improves cardiometabolic health in individuals with overweight and obesity; however, weight loss can also result in bone loss and increased fracture risk. Weight-loss-induced bone loss may be attenuated with exercise. Our aim was to compare changes in bone mineral density (BMD) in adults with overweight and obesity who undertook diet-induced weight loss alone or in combination with exercise.MethodsWe included randomized controlled trials (RCTs) in adults with overweight or obesity (aged ≥18 years; body mass index ≥25 kg/m2) that prescribed diet-induced weight loss alone or in combination with supervised exercise, and measured any bone structural parameters. Risk of bias was assessed using the Cochrane Risk of Bias tool. Random-effects meta-analyses determined mean changes and net mean differences (95% confidence intervals (95%CIs)) in the percentage of areal BMD (aBMD) change between groups.ResultsWe included 9 RCTs. Diet-induced weight loss led to significant losses in femoral neck aBMD (mean change: −1.73% (95%CI: −2.39% to −1.07%), p < 0.001) and total hip aBMD (−2.19% (95%CI: −3.84% to −0.54%), p = 0.009). Femoral neck aBMD losses were significantly greater in the diet-induced weight loss group compared to the exercise plus diet-induced weight loss group (net difference: −0.88% (95%CI: −1.73% to −0.03%)); however, there were no differences in aBMD changes at any other skeletal site: total hip (−1.96% (95%CI: −4.59% to 0.68%)) and lumbar spine (−0.48% (95%CI: −1.81% to 0.86%)). aBMD changes did not differ significantly according to exercise modality (resistance exercise, aerobic exercise, or a combination of the two) during diet-induced weight loss.ConclusionDiet-induced weight loss led to greater femoral neck bone loss compared to diet-induced weight loss plus exercise. Bone loss at the total hip and lumbar spine was not attenuated by exercise during diet-induced weight loss. The lack of consistent skeletal benefits may be due to the insufficient duration and/or training intensities of most exercise interventions. Additional RCTs with appropriate, targeted exercise interventions should be conducted.  相似文献   

11.
BackgroundCardiorespiratory fitness (CRF) is inversely associated with mortality in apparently healthy subjects and in some clinical populations, but evidence for the association between CRF and all-cause and/or cardiovascular disease (CVD) mortality in patients with established CVD is lacking. This study aimed to quantify this association.MethodsWe searched for prospective cohort studies that measured CRF with cardiopulmonary exercise testing in patients with CVD and that examined all-cause and CVD mortality with at least 6 months of follow-up. Pooled hazard ratios (HRs) were calculated using random-effect inverse-variance analyses.ResultsData were obtained from 21 studies and included 159,352 patients diagnosed with CVD (38.1% female). Pooled HRs for all-cause and CVD mortality comparing the highest vs. lowest category of CRF were 0.42 (95% confidence interval (95%CI): 0.28–0.61) and 0.27 (95%CI: 0.16–0.48), respectively. Pooled HRs per 1 metabolic equivalent (1-MET) increment were significant for all-cause mortality (HR = 0.81; 95%CI: 0.74–0.88) but not for CVD mortality (HR = 0.75; 95%CI: 0.48–1.18). Coronary artery disease patients with high CRF had a lower risk of all-cause mortality (HR = 0.32; 95%CI: 0.26–0.41) than did their unfit counterparts. Each 1-MET increase was associated with lower all-cause mortality risk among coronary artery disease patients (HR = 0.83; 95%CI: 0.76–0.91) but not lower among those with heart failure (HR = 0.69; 95%CI: 0.36–1.32).ConclusionA better CRF was associated with lower risk of all-cause mortality and CVD. This study supports the use of CRF as a powerful predictor of mortality in this population.  相似文献   

12.
BackgroundLittle is known about the association between different types of physical activity (PA) and chronic back conditions (CBCs) at the population level. We investigated the association between levels of total and type-specific PA participation and CBCs.MethodsThe sample comprised 60,134 adults aged ≥16 years who participated in the Health Survey for England and Scottish Health Survey from 1994 to 2008. Multiple logistic regression models, adjusted for potential confounders, were used to examine the association between total and type-specific PA volume (walking, domestic activity, sport/exercise, cycling, football/rugby, running/jogging, manual work, and housework) and the prevalence of CBCs.ResultsWe found an inverse association between total PA volume and prevalence of CBCs. Compared with inactive participants, the fully adjusted odds ratio (OR) for very active participants (≥15 metabolic equivalent h/week) was 0.77 (95% confidence interval (CI): 0.69–0.85). Participants reporting ≥300 min/week of moderate-intensity activity and ≥75 min/week of vigorous-intensity activity had 24% (95%CI: 6%–39%) and 21% (95%CI: 11%–30%) lower odds of CBCs, respectively. Higher odds of CBCs were observed for participation in high-level manual domestic activity (OR = 1.22; 95%CI: 1.00–1.48). Sport/exercise was associated with CBCs in a less consistent manner (e.g., OR = 1.18 (95%CI: 1.06–1.32) for low levels and OR = 0.82 (95%CI: 0.72–0.93) for high levels of sport/exercise).ConclusionPA volume is inversely associated with the prevalence of CBCs.  相似文献   

13.
BackgroundChronic ankle instability (CAI) is a common sequela following an acute lateral ankle sprain (LAS). To treat an acute LAS more effectively and efficiently, it is important to identify patients at substantial risk for developing CAI. This study identifies magnetic resonance imaging (MRI) manifestations for predicting CAI development after a first episode of LAS and explores appropriate clinical indications for ordering MRI scans for these patients.MethodsAll patients with a first-episode LAS who received plain radiograph and MRI scanning within the first 2 weeks after LAS from December 1, 2017 to December 1, 2019 were identified. Data were collected using the Cumberland Ankle Instability Tool at final follow-up. Demographic and other related clinical variables, including age, sex, body mass index, and treatment were also recorded. Univariable and multivariable analyses were performed successively to identify risk factors for CAI after first-episode LAS.ResultsA total 131 out of 362 patients with a mean follow-up of 3.0 ± 0.6 years (mean ± SD; 2.0–4.1 years) developed CAI after first-episode LAS. According to multivariable regression, development of CAI after first-episode LAS was associated with 5 prognostic factors: age (odds ratio (OR) = 0.96, 95% confidence interval (95%CI): 0.93–1.00, p = 0.032); body mass index (OR = 1.09, 95%CI: 1.02–1.17, p = 0.009); posterior talofibular ligament injury (OR = 2.17, 95%CI: 1.05–4.48, p = 0.035); large bone marrow lesion of the talus (OR = 2.69, 95%CI: 1.30–5.58, p = 0.008), and Grade 2 effusion of the tibiotalar joint (OR = 2.61, 95%CI: 1.39–4.89, p = 0.003). When patients had at least 1 positive clinical finding in the 10-m walk test, anterior drawer test, or inversion tilt test, they had a 90.2% sensitivity and 77.4% specificity in terms of detecting at least 1 prognostic factor by MRI.ConclusionMRI scanning is valuable in predicting CAI after first-episode LAS for those patients with at least 1 positive clinical finding in the 10-m walk test, anterior drawer test, and inversion tilt test. Further prospective and large-scale studies are necessary for validation.  相似文献   

14.
BackgroundThere is controversial evidence regarding the effect of acute resistance exercise (ARE) on heart rate variability (HRV) parameters, which indicates the activities of the cardiac autonomic nervous system. The aim of this study was to perform a systematic review and meta-analysis of the literature on the effect of ARE on HRV parameters and identify its possible moderating factors.MethodsThe PubMed–Medline, Web of Science, SPORTDiscus, and Cochrane Library databases were searched. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration was followed, and the methodological quality of the studies was evaluated. The level of significance was set at p ≤ 0.05. Twenty-six studies met the inclusion criteria. Main effect analyses between pre- and post-test interventions demonstrated an increase in normalized units low frequency (p < 0.001; standardized mean difference (SMD) = 0.78; 95% confidence interval (95%CI): 0.46?1.11) and low frequency/high frequency ratio (p < 0.001; SMD = 0.82; 95%CI: 0.64?0.99) and a decrease in standard deviation of the normal-to-normal (NN) interval (p < 0.001; SMD = –0.58; 95%CI: –0.85 to –0.30), root mean square of the successive differences (p < 0.001; SMD = –1.01; 95%CI: –1.29 to –0.74), and normalized units high frequency (p < 0.001; SMD: –1.08; 95%CI: –1.43 to –0.73) following ARE in healthy individuals range: 15 ± 1 to 48 ± 2 years; mean ± SD).ResultsThere were differences between the subgroups in the number of sets used in an exercise (p = 0.05) for root mean square of the successive differences, as well as for exercise intensity (p = 0.01) and rest between sets (p = 0.05) for normalized units high frequency. Interestingly, there were differences between the subgroups in training volume for root mean square of the successive differences (p = 0.01), normalized units high frequency (p = 0.003) and normalized units low frequency (p = 0.02).ConclusionOverall, there was a withdrawal of cardiac parasympathetic and activation of cardiac sympathetic modulations following ARE, and these changes were greater with higher training volume ～30 min after ARE in healthy individuals. Furthermore, the number of sets, intensity, and rest between sets affected HRV parameters. However, gender, body mass index, and training status did not influence the changes in HRV parameters as a response to ARE.  相似文献   

15.
BackgroundWhether or not there is targeted pharmacotherapy for dementia, an active and healthy lifestyle that includes physical activity (PA) may be a better option than medication for preventing dementia. We examined the association between leisure-time sedentary behavior (SB) and the risk of dementia incidence and mortality. We further quantified the effect on dementia risk of replacing sedentary time with an equal amount of time spent on different physical activities.MethodsIn the UK Biobank, 484,169 participants (mean age = 56.5 years; 45.2% men) free of dementia were followed from baseline (2006–2010) through July 30, 2021. A standard questionnaire measured individual leisure-time SB (watching TV, computer use, and driving) and PA (walking for pleasure, light and heavy do-it-yourself activity, strenuous sports, and other exercise) frequency and duration in the 4 weeks prior to evaluation. Apolipoprotein E (APOE) genotype data were available for a subset of 397,519 (82.1%) individuals. A Cox proportional hazard model and an isotemporal substitution model were used in this study.ResultsDuring a median 12.4 years of follow-up, 6904 all-cause dementia cases and 2115 deaths from dementia were recorded. In comparison to participants with leisure-time SB <5 h/day, the hazard ratio ((HR), 95% confidence interval (95%CI)) of dementia incidence was 1.07 (1.02–1.13) for 5–8 h/day and 1.25 (1.13–1.38) for >8 h/day, and the HR of dementia mortality was 1.35 (1.12–1.61) for >8 h/day. A 1 standard deviation increment of sedentary time (2.33 h/day) was strongly associated with a higher incidence of dementia and mortality (HR = 1.06, 95%CI: 1.03–1.08 and HR = 1.07, 95%CI: 1.03–1.12, respectively). The association between sedentary time and the risk of developing dementia was more profound in subjects <60 years than in those ≥60 years (HR = 1.26, 95%CI: 1.00–1.58 vs. HR = 1.21, 95%CI: 1.08–1.35 in >8 h/day, p for interaction = 0.013). Replacing 30 min/day of leisure sedentary time with an equal time spent in total PA was associated with a 6% decreased risk and 9% decreased mortality from dementia, with exercise (e.g., swimming, cycling, aerobics, bowling) showing the strongest benefit (HR = 0.82, 95%CI: 0.78–0.86 and HR = 0.79, 95%CI: 0.72–0.86). Compared with APOE ε4 noncarriers, APOE ε4 carriers are more likely to see a decrease in Alzheimer's disease incidence and mortality when PA is substituted for SB.ConclusionLeisure-time SB was positively associated with the risk of dementia incidence and mortality. Replacing sedentary time with equal time spent doing PA may be associated with a significant reduction in dementia incidence and mortality risk.  相似文献   

16.
The purpose of this systematic review and meta-analysis is to assess the effect of concurrent high intensity interval training (HIIT) and resistance training (RT) on strength and hypertrophy. Five electronic databases were searched using terms related to HIIT, RT, and concurrent training. Effect size (ES), calculated as standardised differences in the means, were used to examine the effect of concurrent HIIT and RT compared to RT alone on muscle strength and hypertrophy. Sub-analyses were performed to assess region-specific strength and hypertrophy, HIIT modality (cycling versus running), and inter-modal rest responses. Compared to RT alone, concurrent HIIT and RT led to similar changes in muscle hypertrophy and upper body strength. Concurrent HIIT and RT resulted in a lower increase in lower body strength compared to RT alone (ES = ?0.248, p = 0.049). Sub analyses showed a trend for lower body strength to be negatively affected by cycling HIIT (ES = ?0.377, p = 0.074) and not running (ES = ?0.176, p = 0.261). Data suggests concurrent HIIT and RT does not negatively impact hypertrophy or upper body strength, and that any possible negative effect on lower body strength may be ameliorated by incorporating running based HIIT and longer inter-modal rest periods.  相似文献   

17.
BackgroundAdopting a healthy lifestyle during childhood could improve physical and mental health outcomes in adulthood and reduce relevant disease burdens. However, the lifestyles of children with mental, behavioral, and developmental disorders (MBDDs) remains under-described within the literature of public health field. This study aimed to examine adherence to 24-hour movement guidelines among children with MBDDs compared to population norms and whether these differences are affected by demographic characteristics.MethodsData were from the 2016–2020 National Survey of Children's Health—A national, population-based, cross-sectional study. We used the data of 119,406 children aged 6–17 years, which included 38,571 participants with at least 1 MBDD and 80,835 without. Adherence to the 24-hour movement guidelines was measured using parent-reported physical activity, screen time, and sleep duration.ResultsAmong children with MBDDs, 20.3%, 37.0%, 60.7%, and 77.3% met the physical activity, screen time, sleep, and at least 1 of the 24-hour movement guidelines. These rates were lower than those in children without MBDDs (22.8%, 46.2%, 66.7%, and 83.4%, respectively; all p < 0.001). Children with MBDDs were less likely to meet these guidelines (odds ratio (OR) = 1.21, 95% confidence interval (95%CI): 1.13–1.30; OR = 1.37, 95%CI: 1.29–1.45; OR = 1.29, 95%CI: 1.21–1.37; OR = 1.45, 95%CI: 1.35–1.56) than children without MBDDs. Children with emotional disorders had the highest odds of not meeting these guidelines (OR = 1.43, 95%CI: 1.29–1.57; OR = 1.48, 95%CI: 1.37–1.60; OR = 1.49, 95%CI: 1.39–1.61; OR = 1.72, 95%CI: 1.57–1.88) in comparison to children with other MBDDs. Among children aged 12–17 years, the difference in proportion of meeting physical activity and screen time guidelines for children with vs. children without MBDD was larger than that among children aged 6–11 years. Furthermore, the above difference of meeting physical activity guidelines in ethnic minority children was smaller than that in white children.ConclusionChildren with MBDDs were less likely to meet individual or combined 24-hour movement guidelines than children without MBDDs. In educational and clinical settings, the primary focus should be on increasing physical activity and limiting screen time in children aged 12–17 years who have MBDDs; and specifically for white children who have MBDDs, increasing physical activity may help.  相似文献   

18.
ObjectiveThis cross-sectional study examined environmental correlates of sedentary behavior (SB) and physical activity (PA) in preschool children in the urban area of Tianjin, China.MethodsData were collected from the Physical Activity and Health in Tianjin Chinese Children study, involving healthy children 3–6 years old and their families. In all children (n = 980), leisure-time SB (LTSB) and leisure-time PA (LTPA) were reported in min/day by parents. In a subgroup (n = 134), overall sedentary time, light PA, and moderate-to-vigorous PA (MVPA) were objectively measured using ActiGraph accelerometry (≥3 days, ≥10 h/day). Environmental correlates were collected using a questionnaire that included home and neighborhood characteristics (e.g., traffic safety, presence of physical activity facilities) and children's behaviors. Potential correlates were identified using linear regression analysis.ResultsMultiple linear regression analysis showed that “having grandparents as primary caregivers” (βs and 95% confidence intervals (95%CIs) for overall sedentary time: 29.7 (2.1–57.2); LTSB (ln): 0.19 (0.11–0.28)) and “having a television (for LTSB (ln): 0.13 (0.00–0.25)) or computer (for LTSB (ln): 0.13 (0.03–0.23)) in the child's bedroom” were both associated with higher SB. Furthermore, “having grandparents as primary caregivers” was associated with less MVPA (β (95%CI): ?7.6 (?14.1 to ?1.2)), and “active commuting to school by walking” correlated with more MVPA (β (95%CI): 9.8 (2.2–17.4)). The path model showed that “more neighborhood PA facilities close to home” was indirectly related to higher LTPA (ln), which was partly mediated by “outdoor play” (path coefficients (95%CI): 0.005 (0.002–0.008)) and “going to these facilities more often” (path coefficients (95%CI): 0.013 (0.008–0.018)). Traffic safety was not a correlate.ConclusionFamily structure and media exposure in the home maybe important factors in shaping preschoolers’ PA patterns. Built environmental correlates could indirectly influence preschoolers’ LTPA through parental help with engaging in active behaviors.  相似文献   

19.
Objective: We sought to investigate the longitudinal associations of moderate-to-vigorous physical activity(MVPA) and pubertal development with academic achievement in adolescents.Methods: A total of 635 adolescents(283 boys, 352 girls) aged 11-13 years participated in the study. MVPA was assessed by the Health Behaviour in School-aged Children study questionnaire, and pubertal development was assessed by the Pubertal Development Scale at beginning of the 6 th grade(baseline) and end of the 7 th grade(follow-up). Grade point average(GPA) at the end of Grades 5 and 7 was computed from data acquired from the school registers. The data were analyzed using linear regression and analyses of covariance.Results: In boys, MVPA was positively associated with GPA at baseline after adjustment for age(b = 0.144, 95% confidence interval(CI):0.028-0.260, p = 0.028). In girls, the Pubertal Development Scale was positively associated with GPA at baseline(b = 0.104, 95%CI: -0.004 to0.211, p = 0.058) and follow-up(b = 0.104, 95%CI: -0.002 to 0.211, p = 0.055) after adjustment for age, and these associations strengthened after further adjustment for MVPA(p < 0.05). Adolescents who were inactive at baseline or at baseline and follow-up had lower GPA during followup than their continuously highly active peers(mean difference = -0.301, 95%CI: -0.543 to -0.058, p = 0.009) and all other adolescents(mean difference = -0.247, 95%CI: -0.475 to -0.019, p = 0.029). These differences were greater in girls than in boys.Conclusion: Lower levels of MVPA were associated with lower GPA in boys at baseline. Girls who were continuously inactive had lower GPA over the follow-up period than those who were continuously active. Finally, earlier pubertal development was associated with better academic achievement in girls.  相似文献   

20.
PurposeThe aim of the present study was to assess both the credibility and strength of evidence arising from systematic reviews with meta-analyses of observational studies on handgrip strength and health outcomes.MethodsAn umbrella review of systematic reviews with meta-analyses of observational studies was conducted. We assessed meta-analyses of observational studies based on random-effect summary effect sizes and their p values, 95% prediction intervals, heterogeneity, small-study effects, and excess significance. We graded the evidence from convincing (Class I) to weak (Class IV).ResultsFrom 504 articles returned in a search of the literature, 8 systematic reviews were included in our review, with a total of 11 outcomes. Overall, nine of the 11 of the outcomes reported nominally significant summary results (p < 0.05), with 4 associations surviving the application of the more stringent p value (p < 10−6). No outcome presented convincing evidence. Three associations showed Class II evidence (i.e., highly suggestive): (1) higher handgrip values at baseline were associated with a minor reduction in mortality risk in the general population (n = 34 studies; sample size = 1,855,817; relative risk = 0.72, 95% confidence interval (95%CI): 0.67–0.78), (2) cardiovascular death risk in mixed populations (n = 15 studies; relative risk = 0.84, 95%CI: 0.78–0.91), and (3) incidence of disability (n = 7 studies; relative risk = 0.76, 95%CI: 0.66–0.87).ConclusionThe present results show that handgrip strength is a useful indicator for general health status and specifically for early all-cause and cardiovascular mortality, as well as disability. To further inform intervention strategies, future research is now required to fully understand mechanisms linking handgrip strength scores to these health outcomes.  相似文献   

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