Factors that affect heart rate variability following acute resistance exercise: A systematic review and meta-analysis

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.     

Does exercise have a protective effect on cognitive function under hypoxia? A systematic review with meta-analysis

ObjectiveThis study aimed to examine (1) the independent effects of hypoxia on cognitive function and (2) the effects of exercise on cognition while under hypoxia.MethodsDesign: Systematic review with meta-analysis. Data sources: PubMed, Scopus, Web of Science, PsychInfo, and SPORTDiscus were searched. Eligibility criteria for selecting studies: randomized controlled trials and nonrandomized controlled studies that investigated the effects of chronic or acute exercise on cognition under hypoxia were considered (Aim 2), as were studies investigating the effects of hypoxia on cognition (Aim 1).ResultsIn total, 18 studies met our inclusionary criteria for the systematic review, and 12 studies were meta-analyzed. Exposure to hypoxia impaired attentional ability (standardized mean difference (SMD) = –0.4), executive function (SMD = –0.18), and memory function (SMD = –0.26), but not information processing (SMD = 0.27). Aggregated results indicated that performing exercise under a hypoxia setting had a significant effect on cognitive improvement (SMD = 0.3, 95% confidence interval: 0.14 – 0.45, I² = 54%, p < 0.001). Various characteristics (e.g., age, cognitive task type, exercise type, exercise intensity, training type, and hypoxia level) moderated the effects of hypoxia and exercise on cognitive function.ConclusionExercise during exposure to hypoxia improves cognitive function. This association appears to be moderated by individual and exercise/hypoxia-related characteristics.     

中等强度有氧运动对高血脂患者血脂水平影响的元分析——基于随机对照试验的证据

目的: 评价中等强度有氧运动对高血脂患者血脂水平的影响效果。方法: 检索Google Scholar、PubMed、Web of Science(WOS)、EMBASE、维普、知网和万方数据库中关于中等强度有氧运动干预高血脂患者血脂水平的随机对照试验(RCT),检索期限从各数据库收录时间起至2020年12月。采用Stata 14.0 软件进行meta分析。结果: 共纳入13个RCT,826例患者。与对照组相比,中等强度有氧运动对高血脂患者总胆固醇(TC)(SMD=-0.94,95% CI-0.15~-0.74, P<0.001)、甘油三酯(TG)(SMD=-0.95,95%CI:-1.41~-0.50, P<0.001)、高密度脂蛋白胆固醇(HDL-C)(SMD=0.95(95%CI: 0.79~-1.11,P<0.001),低密度脂蛋白胆固醇(LDL-C)(SMD=-1.36(95%CI:-1.53~-1.19,P< 0.001)水平均有显著影响。结论: 中等强度有氧运动降低了血清中TC总量、TG和LDL-C水平,升高了HDL-C水平。每周6~7次、每次30~90分钟、坚持24~48周的中等轻度有氧运动可以作为高血脂患者改善血脂水平的运动处方。鉴于该研究还存在一定的局限性,仍需高质量的RCT予以论证。     

Do people with low back pain walk differently? A systematic review and meta-analysis

BackgroundThe biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain (LBP). Despite substantial research, it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP. The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls.MethodsA search was conducted in PubMed, CINAHL, SPORTDiscus, and PsycINFO in June 2019 and was repeated in December 2020. Studies were included if they reported biomechanical characteristics of individuals with and without LBP during steady-state or perturbed walking and running. Biomechanical data included spatiotemporal, kinematic, kinetic, and electromyography variables. The reporting quality and potential for bias of each study was assessed. Data were pooled where possible to compare the standardized mean differences (SMD) between back pain and back-healthy control groups.ResultsNinety-seven studies were included and reviewed. Two studies investigated acute pain and the rest investigated persistent pain. Nine studies investigated running gait. Of the studies, 20% had high reporting quality/low risk of bias. In comparison with back-healthy controls, individuals with persistent LBP walked slower (SMD = –0.59, 95% confidence interval (95%CI): –0.77 to –0.42)) and with shorter stride length (SMD = –0.38, 95%CI: –0.60 to –0.16). There were no differences in the amplitude of motion in the thoracic or lumbar spine, pelvis, or hips in individuals with LBP. During walking, coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the persistent LBP groups (SMD = –0.60, 95%CI: –0.90 to –0.30), and individuals with persistent LBP exhibited greater amplitude of activation in the paraspinal muscles (SMD = 0.52, 95%CI: 0.23–0.80). There were no consistent differences in running biomechanics between groups.ConclusionThere is moderate-to-strong evidence that individuals with persistent LBP demonstrate differences in walking gait compared to back-healthy controls.     

The effects of a 20-week exercise program on blood-circulating biomarkers related to brain health in overweight or obese children: The ActiveBrains project

BackgroundEmerging research supports the idea that exercise positively affects neurodevelopment. However, the mechanisms linking exercise with brain health are largely unknown. We aimed to investigate the effect of exercise on (a) blood biomarkers selected based on previous evidence (brain-derived neurotrophic factor, β-hydroxybutyrate (BHB), cathepsin B (CTSB), kynurenine, fibroblast growth factor 21 (FGF21), soluble vascular cell adhesion molecule-1 (sVCAM-1)); and (b) a panel of 92 neurology-related proteins (discovery analysis). We also investigated whether changes in these biomarkers mediate the effects of exercise on brain health (hippocampal structure and function, cognitive performance, and mental health).MethodsWe randomized 81 overweight/obese children (10.1 ± 1.1 years, 41% girls) into 2 groups: either 20 weeks of aerobic plus resistance exercise or control. Candidate biomarkers were assessed using enzyme-linked immunosorbent assay (ELISA) for kynurenine, FGF21, and CTSB; colorimetry for β-hydroxybutyrate; and XMap for brain-derived neurotrophic factor and soluble vascular cell adhesion molecule-1. The 92 neurology-related proteins were analyzed by an antibody-based proteomic analysis.ResultsOur intervention had no significant effect on candidate biomarkers (all p > 0.05). In the discovery analysis, a reduction in circulating macrophage scavenger receptor type-I was observed (standardized differences between groups = –0.3, p = 0.001). This effect was validated using ELISA methods (standardized difference = –0.3, p = 0.01). None of the biomarkers mediated the effects of exercise on brain health.ConclusionsOur study does not support a chronic effect of exercise on candidate biomarkers. We observed that while chronic exercise reduced the levels of macrophage scavenger receptor type-I, it did not mediate the effects of exercise on brain health. Future studies should explore the implications of this novel biomarker for overall health.     

不同方式运动对慢性阻塞性肺疾病患者肺功能及生存质量影响的Meta分析

目的:评价有氧运动、抗阻运动、瑜伽、传统健身功法4种不同运动对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者的影响,从肺功能、6 min步行实验(6 minutes walk test,6MWT)、生存质量3方面,分析比较不同运动方式对慢性阻塞性肺疾病患者肺功能及生存质量的改善效果,有针对性的在慢性阻塞性肺疾病的预防和管理方面提供合理建议和科学依据。方法:建立纳入和排除标准,通过检索PubMed、Web of Science、Embase、Cochrane Library、中国知网(CNKI)、万方等文献数据库,收集运动对慢性阻塞性肺疾病干预的随机对照试验(randomized controlled trial,RCT),运用Revman5.3软件和Stata16.0软件对所纳入文献的结局指标进行分析。结果:共纳入23篇文献,包括1440例受试者,其中实验组719人,对照组721人。Meta分析结果显示,与对照组相比,运动锻炼能够提高COPD患者第1 s用力呼吸容积(forced expiratory volume in the first second,FEV1)(SMD=0.51,95%CI:0.19,0.83,P=0.002)、用力肺活量(forced vital capacity,FVC)(SMD=0.78,95%CI:0.08,1.47,P=0.03)、第1 s用力呼气容积与用力肺活量比值FEV1/FVC(SMD=0.51,95%CI:0.18,1.10,P=0.007)和第1 s用力呼气容积占预计值百分比FEV1/%(SMD=0.35,95%CI:0.10,0.60,P=0.006),延长了6 min步行距离6MWT(SMD=0.49,95%CI:0.33,0.65,P≤0.0001),降低患者呼吸困难指数,提高了生存质量(SMD=-0.59,95%CI:-0.87,-0.31,P≤0.0001)。传统健身功法和有氧运动对COPD患者肺功能、6MWT及生存质量的改善效果更好,抗阻运动和瑜伽虽然在6 min步行距离的加长和生存质量的提高方面效果显著,但在与慢性阻塞性肺疾病最密切相关的肺功能方面的改善效果并不明显。结论:有氧运动、抗阻运动、瑜伽和传统健身功法都对慢性阻塞性肺疾病有一定的预防和改善效果,对肺功能、6MWT及生存质量有明显的改善作用,且传统健身功法和有氧运动的改善效果更全面。     

Exercise and inflammation in coronary artery disease: A systematic review and meta-analysis of randomised trials

ABSTRACT

Current evidence suggests that chronic inflammation contributes to the development of coronary artery disease (CAD). Interestingly, exercise may constitute a method of reducing inflammation in this patient population. As such, this systematic review and meta-analysis examined the evidence generated by randomised studies that investigated the effect of exercise on inflammatory biomarkers in CAD. Literature was sought from various sources. Outcomes were pooled in a random-effects model to calculate standardised mean differences (SMD) with 95% confidence intervals (CI). Twenty-five studies were reviewed; post-intervention C-reactive protein (SMD: ?0.55 (95% CI: ?0.93, ?0.16), P = 0.005), fibrinogen (SMD: ?0.52 (95% CI: ?0.74, ?0.29, P = <0.00001)), and von Willebrand factor (SMD: ?1.57 (95% CI: ?2.23, ?0.92), P = <0.00001) values were significantly lower in exercise groups compared to controls. In addition, qualitative analyses identified evidence that supports a beneficial effect of exercise on these acute-phase reactants. However, the impact of exercise on anti–inflammatory cytokines, adhesion molecules, and chemokines is equivocal, which may be attributed to a paucity of research. Nevertheless, the findings of this review suggest that exercise induces an anti–inflammatory effect in CAD patients. Although, the quality of evidence needs to be improved by further randomised studies with high methodological qualities and large sample sizes.     

The effect of exercise interventions on resting metabolic rate: A systematic review and meta-analysis

ABSTRACT

The systematic review and meta-analysis evaluated the effect of aerobic, resistance and combined exercise on RMR (kCal·day^-1) and performed a methodological assessment of indirect calorimetry protocols within the included studies. Subgroup analyses included energy/diet restriction and body composition changes. Randomized control trials (RCTs), quasi – RCTs and cohort trials featuring a physical activity intervention of any form and duration excluding single exercise bouts were included. Participant exclusions included medical conditions impacting upon RMR, the elderly (≥65 years of age) or pregnant, lactating or post-menopausal women. The review was registered in the International Prospective Register of Systematic Reviews (CRD 42,017,058,503). 1669 articles were identified; 22 were included in the qualitative analysis and 18 were meta-analysed. Exercise interventions (aerobic and resistance exercise combined) did not increase resting metabolic rate (mean difference (MD): 74.6 kCal·day^-1[95% CI: ?13.01, 161.33], P = 0.10). While there was no effect of aerobic exercise on RMR (MD: 81.65 kCal·day^-1[95% CI: ?57.81, 221.10], P = 0.25), resistance exercise increased RMR compared to controls (MD: 96.17 kCal·day^-1[95% CI: 45.17, 147.16], P = 0.0002). This systematic review effectively synthesises the effect of exercise interventions on RMR in comparison to controls; despite heterogenous methodologies and high risk of bias within included studies.     

Metabolic response to 6-week aerobic exercise training and dieting in previously sedentary overweight and obese pre-menopausal women: A randomized trial

BackgroundThe aim of this study was to compare 6 weeks short-term moderate intensity aerobic exercise and dieting on serum metabolomics and cardio-metabolic risk factors in pre-menopausal women.MethodsNinety previously inactive overweight and obese (BMI 25–35 kg/m²) women (age 41.5 ± 7.6 years) were randomized to either a 6-week Nordic walking exercise program (EX, n = 45) or dietary counseling group (DI, n = 45). Body composition, serum glucose, insulin and lipids were measured. Serum low-molecular-weight metabolites and lipid constituents were analyzed by nuclear magnetic resonance spectroscopy. Measurements were done at baseline and 7 days after the last training session.ResultsSix weeks aerobic exercise program yielded reductions in serum free fatty acids (−34.7%, 95% confidence interval (CI), −50 to −18, p < 0.001), glucose (−9.6%, 95%CI, −15 to −4, p < 0.001) and homeostasis model assessment of insulin resistance (HOMA-IR) (−28.7%, 95%CI, −48 to −10, p = 0.005) without changes in body weight or fat mass. Diet counseling resulted in loss of body weight (1.5%, 95%CI, −2.3 to −0.7, p = 0.001) but no changes in free fatty acids, fasting glucose, or HOMA-IR were found.ConclusionOur results indicate that small weight loss does not produce measurable health benefits, whereas short-term regular aerobic exercise can improve glucose and lipid metabolism even in the absence of weight loss in previously sedentary overweight and obese women.     

Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

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.     

Guide for Contributors to Research Quarterly for Exercise and Sport

Purpose: The purpose of this study was to determine differences in cognition between acute bouts of resistance exercise, aerobic exercise, and a nonexercise control in an untrained youth sample. Method: Ninety-four participants performed 30 min of aerobic exercise, resistance exercise, or nonexercise separated by 7 days each in a randomized crossover design. After each exercise intervention, participants were assessed using 2 cognitive tests. The Dot, Word, and Color elements of the Stroop Test (Victoria version) and Parts A and B of the Trail-Making Test were used to measure cognition. Results: Acute resistance and aerobic exercise resulted in similar improvements over nonexercise in all forms of the Stroop Test. Acute aerobic exercise led to improved performance over nonexercise and resistance exercise in Part B of the Trail-Making Test. Neither exercise intervention showed significant changes in time to complete Part A of the Trail-Making Test. Boys outperformed girls on the Stroop Dot and Color Test following acute aerobic exercise, in the Stroop Dot, Word, and Color Test following acute resistance exercise, and in the Stroop Color Test and Trail-Making Test Part B following nonexercise. Conclusions: Both acute resistance and aerobic exercise increased measures of cognition over a nonexercise control in untrained high school youth. These findings suggest the merits of acute resistance exercise as an alternative or complement to aerobic activity for educators aiming to increase youth physical activity and cognitive function concurrently.     

Exercise attenuates bone mineral density loss during diet-induced weight loss in adults with overweight and obesity: A systematic review and meta-analysis

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.     

The potential of a year-round school calendar for maintaining children's weight status and fitness: Preliminary outcomes from a natural experiment

PurposeTo evaluate the potential of a year-round school calendar (180-day school year distributed across 12 months) as an intervention compared to a traditional school calendar (180-day school year distributed across 9 months) for mitigating children's weight gain and fitness loss via a natural experiment.MethodsHeight, weight, and cardiorespiratory fitness (CRF) (i.e., Fitnessgram Progressive Aerobic Cardiovascular Endurance Run) were measured in children (5–12 years old) in 3 schools (2 traditional, 1 year-round, n = 990 students, age = 8.6 ± 2.4 years, 53.1% male, 68.9% African American) from 1 school district. Structure (represented by the presence of a school day) was the independent variable. Changes in body mass index (BMI), age- and sex-specific BMI z-scores (zBMI), BMI percentile, percent of overweight or obese children, and CRF (Progressive Aerobic Cardiovascular Endurance Run laps completed) were assessed for summer 2017 (May–August 2017), school year 2017/2018 (August 2017–May 2018), and summer 2018 (May–August 2018). Primary analyses examined the overall change in weight and CRF from summer 2017 until summer 2018 via multilevel mixed effects regression, with group (traditional vs. year-round calendar), time, and a group-by-time interaction as the independent variables. Secondary regression analyses estimated differences in change within and between groups during each time period, separately.ResultsYear-round students gained less BMI (difference in ∆ = –0.44, 95% confidence interval (CI): –0.67 to –0.03) and less CRF (difference in ∆ = –1.92, 95%CI: –3.56 to –0.28) than students attending a traditional school overall. Compared with traditional students, during both summers, year-round students gained less BMI (summer 2017 difference in ∆ = –0.15, 95%CI: –0.21 to –0.08; summer 2018 difference in ∆ = –0.16, 95%CI: –0.24 to –0.07) and zBMI (summer 2017 difference in ∆ = –0.032, 95%CI: –0.050 to –0.010; summer 2018 difference in ∆ = –0.033, 95%CI: –0.056 to –0.009), and increased CRF (summer 2017 difference in ∆ = 0.40, 95%CI: 0.02–0.85; summer 2018 difference in ∆ = 0.23, 95%CI: –0.25 to 0.74). However, the opposite was observed for the school year, with traditional students gaining less BMI and zBMI and increasing CRF compared with year-round students (difference in BMI ∆ = 0.05, 95%CI: 0.03–0.07; difference in zBMI ∆ = 0.012, 95%CI: 0.005–0.019; difference in Progressive Aerobic Cardiovascular Endurance Run laps ∆ = –0.43, 95%CI: –0.58 to –0.28).ConclusionThe year-round school calendar had a small beneficial impact on children's weight status but not CRF. It is unclear if this benefit to children's weight would be maintained because gains made in the summer were largely erased during the school year. Trajectories of weight and CRF gain/loss were consistent with the structured days hypothesis.     

Immediate effect of high-intensity exercise on brain-derived neurotrophic factor in healthy young adults: A systematic review and meta-analysis

BackgroundAlthough brain-derived neurotrophic factor (BDNF) has been identified as a molecular biomarker of the neurophysiological effects induced by exercise, the acute effects of high-intensity exercise (HIE) on BDNF levels are inconclusive. This study aims to estimate the immediate effects of HIE on BDNF levels in healthy young adults.MethodsA systematic search was conducted in the MEDLINE, Scopus, Cochrane CENTRAL, and SPORTDiscuss databases up to December 2020. Randomized controlled trials (RCTs) and non-RCTs reporting pre–post changes in serum or plasma BDNF after an acute intervention of HIE compared to a control condition were included. Pooled effect sizes (p-ESs) and 95% confidence intervals (95%CIs) were calculated for RCTs using a random effects model with Stata/SE (Version 15.0; StataCorp., College Station, TX, USA). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PROPERO registration number: CRD42020221047.ResultsA total of 22 studies with 552 individuals (age range: 20–31 years; 59.1% male) were included. The meta-analysis included 10 RCTs that reported valid outcome data. Higher BDNF levels were observed when HIE interventions were compared with non-exercise (p-ES = 0.55, 95%CI: 0.12–0.98; I² = 25.7%; n = 4 studies) and light-intensity exercise (p-ES = 0.78, 95%CI: 0.15–1.40; I² = 52.4%; n = 3 studies) but not moderate-intensity exercise (p-ES = 0.93, 95%CI: –0.16 to 2.02; I² = 88.5%; n = 4 studies) conditions.ConclusionIn comparison to non-exercise or light-intensity exercises, an immediate increase in BDNF levels may occur when young adults perform HIE. Given the benefits obtained maximizing circulating BDNF when performing HIE and its potential effects on brain health, our findings suggest that HIE could be recommended by clinicians as a useful exercise strategy to healthy adults.     

体力活动对痴呆患者认知功能干预效果的Meta分析

目的:系统评价体力活动对痴呆患者认知功能的干预效果。方法:计算机检索PubMed、Web of Science、The Cochrane Library、EMbase、Medline、CBM、CNKI、VIP和Wan Fang Data数据库中有关体力活动对痴呆患者认知功能的随机对照试验(RCTs),检索时限均从各个数据库收录起始年限至2018年7月27日,使用PEDro量表进行方法学质量评价,采用Revman5.3软件进行Meta分析,采用Stata14.0软件进行发表偏倚检验。结果:共纳入24个RCT,包括1581例痴呆患者。Meta分析结果显示:体力活动对痴呆患者整体认知功能(MD=2.17,95%CI:1.50,2.84,P<0.00001)有积极的影响。亚组分析结果显示:体力活动对AD患者(MD=2.40,95%CI:1.58,3.23,P<0.00001)与合并AD患者(MD=1.45,95%CI:0.41,2.48,P=0.006)的整体认知功能优于对照组;有氧运动(MD=2.43,95%CI:1.63,3.23,P<0.00001)与混合运动(MD=1.48,95%CI:0.08,2.87,P=0.04)对痴呆患者整体认知功能优于对照组,但抗阻运动(MD=1.70,95%CI:-0.15,3.55,P=0.07)与太极拳运动(MD=0.92,95%CI:-2.98,4.82,P=0.64)与对照组差异无统计学意义;高频率体力活动(MD=1.64,95%CI:0.25,3.04,P=0.02)与低频率体力活动(MD=2.33,95%CI:1.57,3.09,P<0.00001)对痴呆患者的整体认知功能均优于对照组。不同认知领域Meta分析结果显示:体力活动对痴呆患者执行功能(SMD=0.08,95%CI:-0.05,0.20,P=0.22)、TMT-A与TMT-B(SMD=-0.05,95%CI:-0.26,0.16,P=0.63)和记忆功能(SMD=0.15,95%CI:-0.06,0.37,P=0.17)与对照组相比差异无统计学意义,只有注意力(SMD=0.18,95%CI:0.02,0.35,P=0.03)优于对照组。结论:体力活动干预对AD患者与合并AD患者的整体认知功能有积极影响,并且有氧与混合、高频率与低频率的体力活动干预对所有痴呆患者的整体认知功能同样有效,不同认知领域中只有注意力有改善效果。     

Heart rate response and recovery during exercise predict future delirium risk—A prospective cohort study in middle- to older-aged adults

BackgroundDelirium is a neurocognitive disorder characterized by an abrupt decline in attention, awareness, and cognition after surgical/illness-induced stressors on the brain. There is now an increasing focus on how cardiovascular health interacts with neurocognitive disorders given their overlapping risk factors and links to subsequent dementia and mortality. One common indicator for cardiovascular health is the heart rate response/recovery (HRR) to exercise, but how this relates to future delirium is unknown.MethodsElectrocardiogram data were examined in 38,740 middle- to older-aged UK Biobank participants (mean age = 58.1 years, range: 40–72 years; 47.3% males) who completed a standardized submaximal exercise stress test (15-s baseline, 6-min exercise, and 1-min recovery) and required hospitalization during follow-up. An HRR index was derived as the product of the heart rate (HR) responses during exercise (peak/resting HRs) and recovery (peak/recovery HRs) and categorized into low/average/high groups as the bottom quartile/middle 2 quartiles/top quartile, respectively. Associations between 3 HRR groups and new-onset delirium were investigated using Cox proportional hazards models and a 2-year landmark analysis to minimize reverse causation. Sociodemographic factors, lifestyle factors/physical activity, cardiovascular risk, comorbidities, cognition, and maximal workload achieved were included as covariates.ResultsDuring a median follow-up period of 11 years, 348 participants (9/1000) newly developed delirium. Compared with the high HRR group (16/1000), the risk for delirium was almost doubled in those with low HRR (hazard ratio = 1.90, 95% confidence interval (95%CI): 1.30–2.79, p = 0.001) and average HRR (hazard ratio = 1.54, 95%CI: 1.07–2.22, p = 0.020)). Low HRR was equivalent to being 6 years older, a current smoker, or ≥3 additional cardiovascular disease risks. Results were robust in sensitivity analysis, but the risk appeared larger in those with better cognition and when only postoperative delirium was considered (n = 147; hazard ratio = 2.66, 95%CI: 1.46–4.85, p = 0.001).ConclusionHRR during submaximal exercise is associated with future risk for delirium. Given that HRR is potentially modifiable, it may prove useful for neurological risk stratification alongside traditional cardiovascular risk factors.     

Chronotropic incompetence is more frequent in obese adolescents and relates to systemic inflammation and exercise intolerance

BackgroundAdults with obesity may display disturbed cardiac chronotropic responses during cardiopulmonary exercise testing, which relates to poor cardiometabolic health and an increased risk for adverse cardiovascular events. It is unknown whether cardiac chronotropic incompetence (CI) during maximal exercise is already present in obese adolescents and, if so, how that relates to cardiometabolic health.MethodsSixty-nine obese adolescents (body mass index standard deviation score = 2.23 ± 0.32, age = 14.1 ± 1.2 years; mean ± SD) and 29 lean adolescents (body mass index standard deviation score = –0.16 ± 0.84, age = 14.0 ± 1.5 years) performed a maximal cardiopulmonary exercise testing from which indicators for peak performance were determined. The resting heart rate and peak heart rate were used to calculate the maximal chronotropic response index. Biochemistry (lipid profile, glycemic control, inflammation, and leptin) was studied in fasted blood samples and during an oral glucose tolerance test within obese adolescents. Regression analyses were applied to examine associations between the presence of CI and blood or exercise capacity parameters, respectively, within obese adolescents.ResultsCI was prevalent in 32 out of 69 obese adolescents (46%) and 3 out of 29 lean adolescents (10%). C-reactive protein was significantly higher in obese adolescents with CI compared to obese adolescents without CI (p = 0.012). Furthermore, peak oxygen uptake and peak cycling power output were significantly reduced (p < 0.05) in obese adolescents with CI vs. obese adolescents without CI. The chronotropic index was independently related to blood total cholesterol (standardized coefficient β = –0.332; p = 0.012) and C-reactive protein concentration (standardized coefficient β = –0.269; p = 0.039).ConclusionCI is more common in the current cohort of obese adolescents, and is related to systemic inflammation and exercise intolerance.     

A physically active lifestyle is related to a lower level of skin autofluorescence in a large population with chronic-disease (LifeLines cohort)

Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10^-5,95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10^-4,95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10^-4,95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.     

不同运动方式对绝经后女性IL-6、TNF-α和hs-CRP的影响

目的比较12周有氧运动或抗阻训练对绝经后女性白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)和高敏C-反应蛋白(hs-CRP)影响的差异,为制定特异性的运动处方提供依据。方法将符合标准的受试者随机分为有氧运动组(18人),抗阻训练组(17人)和对照组(20人)。有氧运动组和抗阻训练组进行每周3次、共12周的运动干预,对照组保持日常生活习惯不变。实验前后分别测定血清IL-6、TNF-α、hs-CRP等指标。结果 12周运动干预后,有氧运动组血清IL-6较运动前下降了13%(P<0.01),血清TNF-α(P>0.05)和hs-CRP(P>0.05)无显著性变化;抗阻训练组血清IL-6较运动前无显著性变化(P>0.05),但血清TNF-α和hs-CRP分别下降了11%(P<0.05)和26%(P<0.05)。对照组所有指标的变化不明显。相关分析显示,实验前hs-CRP基础值与BMI(r=0.36,P<0.01)、空腹血糖(r=0.23,P<0.05)和IL-6(r=0.22,P<0.01)正相关,与VO2max(r=-0.29,P<0.05)负相关;实验后hs-CRP的变化值与BMI的变化值(r=0.21,P<0.05)正相关。结论 绝经妇女慢性全身性炎症状态与其BMI、血糖水平和体内炎症因子的水平有关;12周有氧运动或抗阻训练均能有效改善绝经后女性慢性全身性炎症状态,但抗阻训练的效果优于有氧运动,其原因与BMI的改善有关。