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.     

Are changes in running economy associated with changes in performance in runners? A systematic review and meta-analysis

Improvements in running economy (RE) are thought to lead to improvements in running performance (P). Multiple interventions have been designed with the aim of improving RE in middle and long-distance runners. The aim of this study was to assess the effect of interventions of at least 2-weeks’ duration on RE and P and to determine whether there is a relationship between changes in RE (ΔRE) and changes in running performance (ΔP). A database search was carried out in Web of Science, Scopus and SPORTDiscus. In accordance with a PRISMA checklist 10 studies reporting 12 comparisons between interventions and controls were included in the review. There was no correlation between percentage ΔRE and percentage ΔP (r = 0.46, P = 0.936, 12 comparisons). There was a low risk of reporting bias but an unclear risk of bias for other items. Meta-analyses found no statistically significant differences between interventions and controls for RE (SMD (95% CI) = ?0.37 (?1.43, 0.69), 204 participants, p = 0.49) or for P (SMD (95% CI) = ?0.65 (?26.02, 24.72, 204 participants, p = 0.99). There is a need for studies of greater statistical power, methodological quality, duration and homogeneity of intervention and population. Standardised measures of performance and greater control over non-intervention training are also required.     

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.     

Are the new starting block facilities beneficial for backstroke start performance?

We aimed to analyse the handgrip positioning and the wedge effects on the backstroke start performance and technique. Ten swimmers completed randomly eight 15 m backstroke starts (four with hands on highest horizontal and four on vertical handgrip) performed with and without wedge. One surface and one underwater camera recorded kinematic data. Standardised mean difference (SMD) and 95% confidence intervals (CI) were used. Handgrip positioning did not affect kinematics with and without wedge use. Handgrips horizontally positioned and feet over wedge displayed greater knee angular velocity than without it (SMD = ?0.82; 95% CI: ?1.56, ?0.08). Hands vertically positioned and feet over wedge presented greater take-off angle (SMD = ?0.81; 95% CI: ?1.55, ?0.07), centre of mass (CM) vertical positioning at first water contact (SMD = ?0.97; 95% CI: ?1.87, ?0.07) and CM vertical velocity at CM immersion (SMD = 1.03; 95% CI: 0.08, 1.98) when comparing without wedge use. Swimmers extended the hip previous to the knee and ankle joints, except for the variant with hands vertically positioned without wedge (SMD = 0.75; 95% CI: ?0.03, 1.53). Swimmers should preserve biomechanical advantages achieved during flight with variant with hands vertically positioned and wedge throughout entry and underwater phase.     

Acute cardiovascular responses to interval exercise: A systematic review and meta-analysis

ABSTRACT

Interval exercise training is increasingly recommended to improve health and fitness; however, it is not known if cardiovascular risk is different from continuous exercise protocols. This systematic review with meta-analyses assessed the effect of a single bout of interval exercise on cardiovascular responses that indicate risk of cardiac fibrillation and infarction compared to continuous exercise. Electronic databases Medline, CINAHL, Embase, Scopus and Cochrane were searched. Key inclusion criteria were: (1) intervals of the same intensity and duration followed by a recovery period and (2) reporting at least one of blood pressure, heart rate variability, arterial stiffness or function. Cochrane Risk of Bias tool and GRADE approach were used. Meta-analyses found that systolic blood pressure responses to interval exercise did not differ from responses to continuous exercise immediately (MD 8 mmHg [95% CI ?32, 47], p = 0.71) or at 60 min following exercise (MD 0 mmHg [95% CI ?2, 1], p = 0.79). However, reductions in diastolic blood pressure and flow-mediated dilation with interval exercise were observed 10–15 min post-exercise. The available evidence indicates that interval exercise does not convey higher cardiovascular risk than continuous exercise. Further investigation is required to establish the safety of interval exercise for clinical populations.     

Effects of exercise by type and duration on quality of life in patients with digestive system cancers: A systematic review and network meta-analysis

BackgroundThere is scant evidence regarding the effects of exercise type and duration on quality of life (QoL) in digestive system cancer (DSC) survivors. We aim to investigate the optimal type and duration of exercise to improve QoL for DSC survivors through a systematic review and network meta-analysis.MethodsA systematic literature search of PubMed, Embase, and Web of Science was performed. Eligibility for study inclusion was limited to studies that were randomized controlled trials involving all kinds of exercise in adult patients with DSCs, and the comparator was in standard care or other types of exercise. The primary outcome was QoL, including general health, physical health, mental health, and role function. Secondary outcomes included cancer-related symptoms such as fatigue, insomnia, depression, anxiety, and duration of hospital stay. The network meta-analyses were performed using a random-effect model.ResultsThe analysis included 32 eligible articles and a total of 2558 participants. Our primary outcome indicated that short-term aerobic exercise significantly enhanced general health (standardized mean difference (SMD) = 0.66, 95% credible intervals (CrIs): 0.05 to 1.30), and also contributed to a better mental health (SMD = 0.38, 95%CrI: –0.05 to 0.81) and role function (SMD = 0.48, 95%CrI: –0.27 to 1.20). Although without significant changes, short-term resistance exercise tended to increase the physical health of patients with DSCs (SMD = 0.69, 95%CrI: –0.07 to 1.50) and effective in alleviating fatigue (SMD = –0.77, 95%CrI: –1.50 to 0.01). Short-term aerobic exercise was related to a lower score of insomnia (SMD = –1.20, 95%CrI: –2.40 to 0.06), depression (SMD = –0.51, 95%CrI: –1.50 to 0.45), and anxiety (SMD = –0.45, 95%CrI: –1.30 to 0.34). All types of exercise related to a trend of declined hospital stays (–0.87 to –5.00 day). Long-term resistance exercise, however, was negatively associated with general health (SMD = –0.33, 95%CrI: –1.70 to 1.00), physical health (SMD = –0.18, 95%CrI: –1.30 to 0.90), and role function (SMD = –1.20, 95%CrI: –2.50 to 0.11).ConclusionThis study suggests that short-term aerobic exercise, with or without resistance exercise programs, enhances QoL (especially for general health) as well as relieves cancer-related symptoms for DSC survivors, while long-term resistance exercise may have negative effects, and thus should be adopted cautiously. These results provide important evidence for the management of DSCs.     

The effect of foot orthoses and insoles on running economy and performance in distance runners: A systematic review and meta-analysis

ABSTRACT

Foot orthoses and insoles are prescribed to runners, however their impact on running economy and performance is uncertain. The aim of this systematic review and meta-analysis was to determine the effect of foot orthoses and insoles on running economy and performance in distance runners. Seven electronic databases were searched from inception until June 2018. Eligible studies investigated the effect of foot orthoses or insoles on running economy (using indirect calorimetry) or running performance. Standardised mean differences (SMDs) were computed and meta-analyses were conducted using random effects models. Methodological quality was assessed using the Quality Index. Nine studies met the criteria and were included: five studies investigated the effect of foot orthoses on running economy and four investigated insoles. Foot orthoses were associated with small negative effects on running economy compared to no orthoses (SMD 0.42 [95% CI 0.17,0.72] p = 0.007). Shock absorbing insoles were also associated with negative effects on running economy, but an imprecise estimate (SMD 0.26 [95% CI ?0.33,0.84] p = 0.83). Quality Index scores ranged from 4 to 15 out of 17. Foot orthoses and shock absorbing insoles may adversely affect running economy in distance runners. Future research should consider their potential effects on running performance.     

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。     

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。     

Quantifying the effects of acute hypoxic exposure on exercise performance and capacity: A systematic review and meta-regression

Objective: To quantify the effects of acute hypoxic exposure on exercise capacity and performance, which includes continuous and intermittent forms of exercise. Design: A systematic review was conducted with a three-level mixed effects meta-regression. The ratio of means method was used to evaluate main effects and moderators providing practical interpretations with percentage change. Data sources: A systemic search was performed using three databases (Google scholar, PubMed and SPORTDiscus). Eligibility criteria for selecting studies: Inclusion was restricted to investigations that assessed exercise performance (time trials (TTs), sprint and intermittent exercise tests) and capacity (time to exhaustion test, TTE) with acute hypoxic (<24?h) exposure and a normoxic comparator. Results: Eighty-two outcomes from 53 studies (N?=?798) were included in this review. The results show an overall reduction in exercise performance/capacity ?17.8?±?3.9% (95% CI ?22.8% to ?11.0%), which was significantly moderated by ?6.5?±?0.9% per 1000 m altitude elevation (95% CI ?8.2% to ?4.8%) and oxygen saturation (?2.0?±?0.4%; 95% CI ?2.9% to ?1.2%). TT (?16.2?±?4.3%; 95% CI ?22.9% to ?9%) and TTE (?44.5?±?6.9%; 95% CI ?51.3% to ?36.7%) elicited a negative effect, whilst indicating a quadratic relationship between hypoxic magnitude and both TTE and TT performance. Furthermore, exercise less than 2 min exhibited no ergolytic effect from acute hypoxia.

Summary/Conclusion: This review highlights the ergolytic effect of acute hypoxic exposure, which is curvilinear for TTE and TT performance with increasing hypoxic levels, but short duration intermittent and sprint exercise seem to be unaffected.     

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.     

Exercise promotes IL-6 release from legs in older men with minor response to unilateral immobilization

Physical inactivity is a major contributor to low-grade systemic inflammation. Most of the studies characterizing interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) release from exercising legs have been done in young, healthy men, but studies on inactivity in older people are lacking. The impact of 14 days of one-leg immobilization (IM) on IL-6 and TNF-α release during exercise in comparison to the contralateral control (CON) leg was investigated. Fifteen healthy men (age 68.1?±?1.1?year (mean?±?SEM); BMI 27.0?±?0.4 kg·m²; VO₂max 33.3?±?1.6 ml·kg^?1·min^?1) performed 45?min of two-leg dynamic knee extensor exercise at 19.5?±?0.9 W. Arterial and femoral venous blood samples from the CON and the IM legs were collected every 15?min during exercise, and thigh blood flow was measured with ultrasound Doppler. Arterial plasma IL-6 concentration increased with exercise (rest vs. 45?min, main effect p?p?p?=?.085, effect size 0.28) higher in the IM leg compared to the CON leg (288 (95% CI: 213–373) vs. 220 (95% CI: 152–299) pg·min^?1, respectively). There was no release of TNF-α in either leg and arterial concentrations remained unchanged during exercise (p?>?.05). In conclusion, exercise induces more pronounced IL-6 secretion in healthy older men. Two weeks of unilateral immobilization on the other hand had only a minor influence on IL-6 release. Neither immobilization nor exercise had an effect on TNF-α release across the working legs in older men.     

Accelerometer and GPS Data to Analyze Built Environments and Physical Activity

ABSTRACT

Purpose: Most built environment studies have quantified characteristics of the areas around participants’ homes. However, the environmental exposures for physical activity (PA) are spatially dynamic rather than static. Thus, merged accelerometer and global positioning system (GPS) data were utilized to estimate associations between the built environment and PA among adults. Methods: Participants (N = 142) were recruited on trails in Massachusetts and wore an accelerometer and GPS unit for 1–4 days. Two binary outcomes were created: moderate-to-vigorous PA (MVPA vs. light PA-to-sedentary); and light-to-vigorous PA (LVPA vs. sedentary). Five built environment variables were created within 50-meter buffers around GPS points: population density, street density, land use mix (LUM), greenness, and walkability index. Generalized linear mixed models were fit to examine associations between environmental variables and both outcomes, adjusting for demographic covariates. Results: Overall, in the fully adjusted models, greenness was positively associated with MVPA and LVPA (odds ratios [ORs] = 1.15, 95% confidence interval [CI] = 1.03, 1.30 and 1.25, 95% CI = 1.12, 1.41, respectively). In contrast, street density and LUM were negatively associated with MVPA (ORs = 0.69, 95% CI = 0.67, 0.71 and 0.87, 95% CI = 0.78, 0.97, respectively) and LVPA (ORs = 0.79, 95% CI = 0.77, 0.81 and 0.81, 95% CI = 0.74, 0.90, respectively). Negative associations of population density and walkability with both outcomes reached statistical significance, yet the effect sizes were small. Conclusions: Concurrent monitoring of activity with accelerometers and GPS units allowed us to investigate relationships between objectively measured built environment around GPS points and minute-by-minute PA. Negative relationships between street density and LUM and PA contrast evidence from most built environment studies in adults. However, direct comparisons should be made with caution since most previous studies have focused on spatially fixed buffers around home locations, rather than the precise locations where PA occurs.     

Differential time responses in inflammatory and oxidative stress markers after a marathon: An observational study

ABSTRACT

Acute and adaptive changes in systemic markers of oxidatively generated nucleic acid modifications (i.e., 8-oxo-7,8-dihydro-2?-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo)) as well as inflammatory cytokines (i.e., C-reactive protein, interleukin-6, interleukin-10, and tumour necrosis factor alpha), a liver hormone (i.e., fibroblast growth factor 21 (FGF21)), and bone metabolism markers (sclerostin, osteocalcin, C-terminal telopeptide, and N-terminal propeptide of type 1 procollagen) were investigated following a marathon in 20 study participants. Immediate changes were observed in inflammatory cytokines, FGF21, and bone metabolism markers following the marathon. In contrast, no immediate changes in urinary excretion of 8-oxodG and 8-oxoGuo were evident. Four days after the marathon, decreased urinary excretion of 8-oxodG (-2.9 (95% CI -4.8;-1.1) nmol/24 h, P < 0.01) and 8-oxoGuo (-5.8 (95% CI -10.3;-1.3) nmol/24 h, P = 0.02) was observed. The excretion rate of 8-oxodG remained decreased 7 days after the marathon compared to baseline (-2.3 (95%CI -4.3;-0.4) nmol/24 h, P = 0.02), whereas the excretion rate of 8-oxoGuo was normalized. In conclusion marathon participation immediately induced a considerable inflammatory response, but did not increase excretion rates of oxidatively generated nucleic acid modifications. In fact, a delayed decrease in oxidatively generated nucleic acid modifications was observed suggesting adaptive antioxidative effects following exercise.     

Effects of interval aerobic training combined with strength exercise on body composition,glycaemic and lipid profile and aerobic capacity of obese rats

The purpose of this study was to investigate the effects of interval aerobic training combined with strength exercise in the same training session on body composition, and glycaemic and lipid profile in obese rats. Sixteen lean Zucker rats and sixteen obese Zucker rats were randomly divided into exercise and sedentary subgroups (4 groups, n = 8). Exercise consisted of interval aerobic training combined with strength exercise in the same training session. The animals trained 60 min/day, 5 days/week for 8 weeks. Body composition, lipid and glycaemic profiles and inflammatory markers were assessed.

Results showed that fat mass was reduced in both lean and obese rats following the exercise training (effect size (95% confidence interval (CI)) = 1.8 (0.5–3.0)). Plasma low-density lipoprotein–cholesterol and fasting glucose were lower in the exercise compared to the sedentary groups (d = 2.0 (0.7–3.2) and 1.8 (0.5–3.0), respectively). Plasma insulin was reduced in exercise compared to sedentary groups (d = 2.1 (0.8–3.4)). Some exercise × phenotype interactions showed that the highest decreases in insulin, homeostatic model assessment-insulin resistance, fasting and postprandial glucose were observed in the obese + exercise group (all, P < 0.01). The findings of this study suggest that interval aerobic training combined with strength exercise would improve body composition, and lipid and glycaemic profiles, especially in obese rats.     

运动干预及营养联合对老年肌少症患者影响的Meta分析

目的:运用Meta分析法综合相关文献,从定量评价角度评估运动干预及营养联合对老年肌少症患者肌肉质量、肌肉力量和身体功能结果的影响。方法:检索中国知网、万方数据库、维普(VIP)数据库、Web of Science、Pubmed、EBSCO等数据库,严格按照纳入与排除标准选取文献,提取数据,进行质量评价,在Review Manager5.3软件上进行统计分析,效应量以加权化均差(SMD)的形式表示。结果:纳入文献共计14篇,其中实验组为运动干预的研究10项,样本量551;实验组为营养联合运动干预的研究9项,样本量542。Meta分析结果显示,与对照组相比,运动干预有效改善老年肌少症患者肌肉力量(腿部力量)[SMD=0.5395%CL=(0.35,0.70),P<0.00001]、身体表现功能(步速)[SMD=0.38,95%CL=(0.04,0.77),P=0.03]。结论:运动干预可以有效改善肌少症患者肌肉力量和身体表现功能,但对于结果不具有显著性的结果指标也并不一定没有作用。在这个领域需要进行高质量的研究来探索治疗肌少症的有效干预方法。     

Outcomes of an Education and Exercise Program for Adults with Type 2 Diabetes,and Comorbidities that Limit their Mobility: A Preliminary Project Report

Purpose: Some adults with type 2 diabetes mellitus (T2DM) have comorbidities and mobility impairments that limit their exercise capacity. In consideration of this, we developed and piloted a program called Active Steps for Diabetes for people with T2DM, comorbidities, and mobility impairments. The purpose of this paper was to report outcomes for the pilot program. Methods: Active Steps for Diabetes, an 8-week program, included instruction on diabetes self-care andgroup and home exercise programs. Twenty-two females (62.7 ± 6.1yrs) with T2DM and self-reported mobility impairments completed the program. Six participants used a walking aid. Outcome measures included two risk factors for coronary artery disease [daily physical activity and body mass index (BMI)], cardiovascular fitness (6-minute walk distance), and knowledge of diabetes-specific exercise guidelines. A two-way repeated measures ANOVA was used to compare outcomes before and after the program and between participants who did and did not use a walking aid. Results: Active Steps for Diabetes was effective in increasing daily physical activity in both groups of subjects (walking aid group: 2.6 days/week [95% confidence interval (CI) = 2.1 to 3.3]; no walking aid group: 1.9 days/week [95% CI=1.2 to 2.5]). This was accompanied by increases in 6-minute walk distances (walking aid group: 54.0 m [95% CI = 36.4 to 71.6]; no walking aid group: 62.6 m [95% CI=55.7 to 69.4]). Changes in BMI were not significant (walking aid group: −0.4 [95% CI = −1.2 to 0.4]; no walking aid group: −.24[95% CI = −.91 to .44]). Increases in knowledge of diabetes-specific exercise guidelines were observed in both groups (walking aid group: 18.8% [95% CI = 11.3 to 26.4]; no walking aid group: 19.3% [95% CI = 16.1 to 22.5]). Discussion:: Physical inactivity and low cardiovascular fitness are predictors of CAD morbidity and mortality in adults with T2DM. This pilot program suggests that a model for diabetes education, incorporating exercise programs developed by a physical therapist, may increase physical activity, improve endurance, and thereby potentially reduce CAD risk in people with T2DM and mobility impairments from comorbidities.Key Words: type 2 diabetes, physical activity     

Muscular adaptations in low- versus high-load resistance training: A meta-analysis

There has been much debate as to optimal loading strategies for maximising the adaptive response to resistance exercise. The purpose of this paper therefore was to conduct a meta-analysis of randomised controlled trials to compare the effects of low-load (≤60% 1 repetition maximum [RM]) versus high-load (≥65% 1 RM) training in enhancing post-exercise muscular adaptations. The strength analysis comprised 251 subjects and 32 effect sizes (ESs), nested within 20 treatment groups and 9 studies. The hypertrophy analysis comprised 191 subjects and 34 ESs, nested with 17 treatment groups and 8 studies. There was a trend for strength outcomes to be greater with high loads compared to low loads (difference = 1.07 ± 0.60; CI: ?0.18, 2.32; p = 0.09). The mean ES for low loads was 1.23 ± 0.43 (CI: 0.32, 2.13). The mean ES for high loads was 2.30 ± 0.43 (CI: 1.41, 3.19). There was a trend for hypertrophy outcomes to be greater with high loads compared to low loads (difference = 0.43 ± 0.24; CI: ?0.05, 0.92; p = 0.076). The mean ES for low loads was 0.39 ± 0.17 (CI: 0.05, 0.73). The mean ES for high loads was 0.82 ± 0.17 (CI: 0.49, 1.16). In conclusion, training with loads ≤50% 1 RM was found to promote substantial increases in muscle strength and hypertrophy in untrained individuals, but a trend was noted for superiority of heavy loading with respect to these outcome measures with null findings likely attributed to a relatively small number of studies on the topic.     

Leucine metabolites do not attenuate training-induced inflammation in young resistance trained men

ABSTRACT

Leucine metabolites may reduce training-induced inflammation; however, there is scant evidence for this assertion. We conducted a double-blind randomized controlled pragmatic trial where 40 male participants were allocated into 4 groups: α-hydroxyisocaproic acid group ([α-HICA], n = 10, Fat-free mass [FFM] = 62.0 ± 7.1 kg), β-hydroxy-β-methylbutyrate free acid group ([HMB-FA], n = 11, FFM = 62.7 ± 10.5 kg), calcium β-hydroxy-β-methylbutyrate group ([HMB-Ca], n = 9, FFM = 65.6 ± 10.1 kg) or placebo group ([PLA]; n = 10, FFM = 64.2 ± 5.7 kg). An 8-week whole-body resistance training routine (3 training sessions per week) was employed to induce gains in skeletal-muscle thickness. Skeletal muscle thickness (MT), one repetition maximum (1RM), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP) and tumour necrosis factor alpha (TNF-α) were assessed at baseline and at the end of weeks 4 and 8. Time-dependent increases were detected from baseline to week 8 for MT (vastus lateralis: p = 0.009; rectus femoris: p = 0.018), 1RM (back squat: α-HICA, 18.5% ± 18.9%; HMB-FA, 23.2% ± 16%; HMB-Ca, 10.5% ± 13.8%; PLA, 19.7% ± 9% and bench press: α-HICA, 13.8% ± 19.1%; HMB-FA, 15.5% ± 9.3%; HMB-Ca, 10% ± 10.4%; PLA, 14.4 ± 11.3%, both p < 0.001), IL-6, hsCRP (both p < 0.001) and TNF-α (p = 0.045). No differences were found between groups at any time point. No leucine metabolite attenuated inflammation during training. Additionally, backwards elimination regressions showed that no circulating inflammatory marker consistently shared variance with the change in any outcome. Using leucine metabolites to modulate inflammation cannot be recommended from the results obtained herein. Furthermore, increases in inflammatory markers, from training, do not correlate with any outcome variable and are likely the result of training adaptations.     

Acute and chronic effect of sodium bicarbonate ingestion on Wingate test performance: a systematic review and meta-analysis

The aim of this study was to perform a systematic review and meta-analysis on the acute and chronic effects of sodium bicarbonate (NaHCO₃) ingestion on Wingate performance. Following a search through PubMed, Scopus and Web of Science, 9 studies were found meeting inclusion criteria (6 acute and 3 chronic). Random-effects meta-analysis of standardized mean difference (SMD) for peak and mean power was performed. Study quality was assessed using the QualSyst. Results of the meta-analysis showed that acute ingestion of NaHCO₃ did not improve Wingate test peak (weighted average effect size Hedges’s g = 0.02, 95%CI: – 0.19 to 0.23, P = 0.87) or mean power (weighted average effect size Hedges’s g = 0.15, 95%CI: ?0.06 to 0.36, P = 0.92). However, chronic ingestion of NaHCO₃ improved Wingate test peak (weighted average effect size Hedges’s g = 1.21, 95%CI: 0.83 to 1.42, P = 0.001) and mean power (weighted average effect size Hedges’s g = 1.26, 95%CI: 0.96 to 1.56, P = 0.001). Quality assessment of selected articles was classified as strong. This meta-analysis provides evidence that chronic, but not acute, ingestion of NaHCO₃ increases both Wingate test peak and mean power.