Dose-Response Relationships of Resistance Training in Healthy Old Adults: A Systematic Review and Meta-Analysis.
Dose-Response Relationships of Resistance Training in Healthy Old Adults: A Systematic Review and Meta-Analysis.
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DOI：
10.1007/s40279-015-0385-9
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
Granacher U
中科院分区：
文献类型：
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作者：
Borde R;Hortobágyi T;Granacher U
阻力训练（RT）是一种经常用于改善老年肌肉力量和形态的干预措施。然而，在健康老年人中，关于特定 RT 变量（例如训练周期、频率、强度、训练量）的基于证据的剂量反应关系尚不清楚。本系统评价和荟萃分析的目的是确定放疗对肌肉力量和形态测量的一般影响，并通过分析可以改善健康老年人肌肉力量和形态的随机对照试验（RCT）来提供放疗变量的剂量-反应关系。从 1984 年 1 月到 2015 年 6 月，我们在电子数据库 PubMed、Web of Science 和 Cochrane 图书馆中进行了计算机化、系统性文献检索，以确定与健康老年人 RT 相关的所有随机对照试验。初步检索确定了 506 项研究，最终得出 25 项研究。仅纳入了研究放疗对平均年龄 65 岁及以上成年人的影响的随机对照试验。这 25 项研究量化了至少一项肌肉力量或形态的测量，并充分描述了训练变量（例如训练周期、频率、训练量、强度）。我们通过计算干预组和对照组之间的加权受试者间标准化平均差 (SMDb) 来量化 RT 对肌肉力量和形态测量的总体影响。我们分析了单次最大重复次数 (1RM)、等长条件下最大自主收缩 (MVC) 和肌肉形态（即肌肉的横截面积或体积或厚度）的主要结果数据，并通过物理治疗证据数据库 (PEDro) 量表评估了方法学研究质量。使用 I2 和 χ2 统计数据评估研究之间的异质性。计算随机效应元回归来解释关键训练变量对 RT 在肌肉力量和形态方面的有效性的影响。对于元回归，训练变量分为以下子类别：训练量、强度和休息。除了元回归之外，还针对单个训练变量（例如训练频率）独立计算剂量反应关系。 RT 显着提高了肌肉力量（平均 SMDbs = 1.57；25 项研究），但对肌肉形态测量的影响很小（平均 SMDbs = 0.42；9 项研究）。具体而言，RT 对上肢（平均 SMDbs = 1.61；11 项研究）和下肢（平均 SMDbs = 1.76；19 项研究）的 1RM 产生较大影响，对下肢 MVC（平均 SMDbs = 0.76；4 项研究）产生中等影响。元回归结果显示，变量“训练时间”（p = 0.04）和“强度”（p < 0.01）以及“紧张总时间”（p < 0.01）对肌肉力量有显着影响，最长训练时间（平均 SMDbs = 2.34；50-53 周）、强度为 70-79% 的效果最大。 1RM（意味着 SMDbs = 1.89），张力下的总时间为 6.0 秒（平均 SMDbs = 3.61）。组间休息有显着性趋势 (p = 0.06)，其中 60 秒对肌肉力量的影响最大（平均 SMDbs = 4.68；两项研究）。我们还确定了其余训练变量对肌肉力量的独立影响。以下独立计算的训练变量对于改善肌肉力量测量最有效：每周两次的训练频率（平均 SMDbs = 2.13），每次练习两到三组的训练量（平均 SMDbs = 2.99），每组重复七到九次（平均 SMDbs = 1.98），重复之间休息 4.0 秒（SMDbs = 3.72）。关于肌肉形态的测量，少量已确定的研究使我们能够仅计算子类别训练量的元回归。没有任何单一训练量变量能够显着预测 RT 对肌肉形态测量的影响。独立计算额外的训练变量以检测单个训练变量的最大效果。训练周期为 50-53 周，训练频率为每周 3 节，每次练习的训练量为 2 到 3 组，每组重复 7 到 9 次，训练强度为 1RM 的 51 到 69 %，总紧张时间为 6.0 秒，组间休息 120 秒，重复之间休息 2.5 秒，结果证明是最有效的。由于整体方法学研究质量较差（平均 PEDro 评分 4.6 分）且肌肉力量存在相当大的异质性（I2 = 80%，χ2 = 163.1，df = 32，p < 0.01），因此必须谨慎解释当前结果。在肌肉形态方面，我们的搜索仅发现了九项研究，这就是为什么我们认为我们的发现是初步的。虽然我们能够根据肌肉力量和形态方面的特定个体训练变量确定剂量反应关系，但不可能确定这些变量之间的任何潜在相互作用。我们认识到结果可能不代表一种一般剂量反应关系的局限性。这项系统的文献综述和荟萃分析证实了 RT 对健康老年人上肢和下肢肌肉力量和肌肉形态的具体测量的有效性。此外，我们能够提取关键训练变量（即训练量、强度、休息）的剂量反应关系，从而告知临床医生和从业者设计针对肌肉力量和形态的有效 RT。训练周期、强度、紧张时间和组间休息对于提高肌肉力量和形态具有重要作用，应在针对健康老年人的运动训练计划中实施。尽管如此，仍需要进一步的研究来揭示健康以及行动受限和/或虚弱老年人放疗后的最佳剂量反应关系。
Resistance training (RT) is an intervention frequently used to improve muscle strength and morphology in old age. However, evidence-based, dose–response relationships regarding specific RT variables (e.g., training period, frequency, intensity, volume) are unclear in healthy old adults. The aims of this systematic review and meta-analysis were to determine the general effects of RT on measures of muscle strength and morphology and to provide dose–response relationships of RT variables through an analysis of randomized controlled trials (RCTs) that could improve muscle strength and morphology in healthy old adults. A computerized, systematic literature search was performed in the electronic databases PubMed, Web of Science, and The Cochrane Library from January 1984 up to June 2015 to identify all RCTs related to RT in healthy old adults. The initial search identified 506 studies, with a final yield of 25 studies. Only RCTs that examined the effects of RT in adults with a mean age of 65 and older were included. The 25 studies quantified at least one measure of muscle strength or morphology and sufficiently described training variables (e.g., training period, frequency, volume, intensity). We quantified the overall effects of RT on measures of muscle strength and morphology by computing weighted between-subject standardized mean differences (SMDbs) between intervention and control groups. We analyzed the data for the main outcomes of one-repetition maximum (1RM), maximum voluntary contraction under isometric conditions (MVC), and muscle morphology (i.e., cross-sectional area or volume or thickness of muscles) and assessed the methodological study quality by Physiotherapy Evidence Database (PEDro) scale. Heterogeneity between studies was assessed using I2 and χ2 statistics. A random effects meta-regression was calculated to explain the influence of key training variables on the effectiveness of RT in terms of muscle strength and morphology. For meta-regression, training variables were divided into the following subcategories: volume, intensity, and rest. In addition to meta-regression, dose–response relationships were calculated independently for single training variables (e.g., training frequency). RT improved muscle strength substantially (mean SMDbs = 1.57; 25 studies), but had small effects on measures of muscle morphology (mean SMDbs = 0.42; nine studies). Specifically, RT produced large effects in both 1RM of upper (mean SMDbs = 1.61; 11 studies) and lower (mean SMDbs = 1.76; 19 studies) extremities and a medium effect in MVC of lower (mean SMDbs = 0.76; four studies) extremities. Results of the meta-regression revealed that the variables “training period” (p = 0.04) and “intensity” (p < 0.01) as well as “total time under tension” (p < 0.01) had significant effects on muscle strength, with the largest effect sizes for the longest training periods (mean SMDbs = 2.34; 50–53 weeks), intensities of 70–79 % of the 1RM (mean SMDbs = 1.89), and total time under tension of 6.0 s (mean SMDbs = 3.61). A tendency towards significance was found for rest in between sets (p = 0.06), with 60 s showing the largest effect on muscle strength (mean SMDbs = 4.68; two studies). We also determined the independent effects of the remaining training variables on muscle strength. The following independently computed training variables are most effective in improving measures of muscle strength: a training frequency of two sessions per week (mean SMDbs = 2.13), a training volume of two to three sets per exercise (mean SMDbs = 2.99), seven to nine repetitions per set (mean SMDbs = 1.98), and a rest of 4.0 s between repetitions (SMDbs = 3.72). With regard to measures of muscle morphology, the small number of identified studies allowed us to calculate meta-regression for the subcategory training volume only. No single training volume variable significantly predicted RT effects on measures of muscle morphology. Additional training variables were independently computed to detect the largest effect for the single training variable. A training period of 50–53 weeks, a training frequency of three sessions per week, a training volume of two to three sets per exercise, seven to nine repetitions per set, a training intensity from 51 to 69 % of the 1RM, a total time under tension of 6.0 s, a rest of 120 s between sets, and a rest of 2.5 s between repetitions turned out to be most effective. The current results must be interpreted with caution because of the poor overall methodological study quality (mean PEDro score 4.6 points) and the considerable large heterogeneity (I2 = 80 %, χ2 = 163.1, df = 32, p < 0.01) for muscle strength. In terms of muscle morphology, our search identified nine studies only, which is why we consider our findings preliminary. While we were able to determine a dose–response relationship based on specific individual training variables with respect to muscle strength and morphology, it was not possible to ascertain any potential interactions between these variables. We recognize the limitation that the results may not represent one general dose–response relationship. This systematic literature review and meta-analysis confirmed the effectiveness of RT on specific measures of upper and lower extremity muscle strength and muscle morphology in healthy old adults. In addition, we were able to extract dose–response relationships for key training variables (i.e., volume, intensity, rest), informing clinicians and practitioners to design effective RTs for muscle strength and morphology. Training period, intensity, time under tension, and rest in between sets play an important role in improving muscle strength and morphology and should be implemented in exercise training programs targeting healthy old adults. Still, further research is needed to reveal optimal dose–response relationships following RT in healthy as well as mobility limited and/or frail old adults.