Comparison of Power Training vs Traditional Strength Training on Physical Function in Older Adults: A Systematic Review and Meta-analysis.

Importance: Strength training exercise is recommended for improving physical function in older adults. However, whether strength training (lifting and lowering weights under control) and power training (PT) (lifting weights fast and lowering under control) are associated with improved physical function in older adults is not clear. Objective: To evaluate whether PT vs traditional strength training is associated with physical function improvement in older adults. Data Sources: Systematic searches of MEDLINE, Embase, Cochrane Central, CINAHL, PsycInfo, PEDro, and SPORTDiscus were conducted from database inception to October 20, 2021. Study Selection: Randomized clinical trials (RCTs) that compared strength training with instructions to move the weight as fast as possible in the lifting phase with traditional strength training in healthy, community-living older adults (age ≥60 years). Data Extraction and Synthesis: Two authors independently selected trials, extracted data, assessed the risk of bias using the Cochrane risk-of-bias tool 2, and assessed the certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach. Summary effect size measures were calculated using a multilevel random-effects model with cluster robust variance estimation and are reported as standardized mean differences (SMDs). Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Main Outcomes and Measures: Primary outcomes included physical function and self-reported physical function. Secondary outcomes included power, strength, muscle mass, walk speed, balance, and adverse effects. Results: A total of 20 RCTs enrolling 566 community-living older adults (mean [SD] age, 70.1 [4.8] years; 368 [65%] women) were included. For the primary outcomes, PT was associated with an improvement in physical function with low-certainty evidence in 13 RCTs (n = 383) (SMD, 0.30; 95% CI, 0.05-0.54) and self-reported function with low-certainty evidence in 3 RCTs (n = 85) (SMD, 0.38; 95% CI, -0.62 to 1.37). The evidence was downgraded by 2 levels for high risk of bias and imprecision for physical function and very serious imprecision for self-reported physical function. Conclusions and Relevance: In this systematic review and meta-analysis, PT was associated with a modest improvement in physical function compared with traditional strength training in healthy, community-living older adults. However, high-quality, larger RCTs are required to draw more definitive conclusions.

Validity, reliability, and measurement error of a sit-to-stand power test in older adults: A pre-registered study.

OBJECTIVES: Lower body power declines with age and is associated with decreased physical function in older adults. However, the majority of the tools available to measure power are expensive and require considerable space and expertise to operate. The purpose of this study was to assess the validity, reliability, and measurement error of a sit-to-stand power test (STSp) to assess lower body power. METHODS: 51 community-dwelling adults, 65 years or older, completed a power test using a pneumatic leg press (LP), the Short Physical Performance Battery (SPPB) that includes a test of balance, usual walking speed, and chair stand tests; Timed Up and Go (TUG) test at both usual and fast paces, and Patient-Reported Outcome Measures (PROMs). A two-week test-retest assessed the reliability in 36 participants. The study hypotheses and analysis were pre-registered prior to data collection and statistical analyses were blinded. RESULTS: The mean age was 71.3 years, with 63% females, and an average SPPB score of 10.6 (median = 12). STSp peak power was strongly correlated with LP (r = 0.90, 95% CI (0.82, 0.94). As hypothesized, the STSp peak power showed similar or higher correlations with physical function tests relative to LP peak power: SPPB (0.41 vs. 0.29), chair stand test (-0.44 vs. -0.35), TUG test at usual pace (-0.37 vs. -0.29) and fast pace (-0.41 vs. -0.34) and balance (0.33 vs. 0.22), but not for mobility (0.34 vs. 0.38) and function (0.41 vs. 0.48) questionnaire. For discriminant validity, as hypothesized, males showed higher STSp peak power compared to females (Δ = 492 W, p < .001, Cohen's d = 2.0). Test-retest assessment yielded an intraclass correlation coefficient of 0.96 and a standard error of measurement of 70.4 W. No adverse events were reported or observed for both tests. CONCLUSION: The STSp showed adequate validity and reliability in measuring lower body power in community-dwelling older adults. The test is quick, relatively inexpensive, safe, and portable and thus should be considered for use in aging research.