The Effects of Different Resistance Training Modalities on Muscle Strength in Community-Dwelling Older Adults: A Network Meta-Analysis

INTRODUCTION: Resistance training is widely recognized as a valuable method to enhance physical function, reduce the risk of falls, and improve overall health, independence and well-being in older adults. The training can be performed through various modalities of which the comparative effects have not yet been thoroughly elucidated. This network meta-analysis (NMA) therefore aims to compare and rank different resistance training modalities regarding their effects on strength outcomes in older adults. METHODS: The studies included in this NMA were identified through a comprehensive search across three health-related and biomedical databases (PubMed, Web of Science, and SPORTDiscus). We included (randomized) controlled trials that assessed the effect of resistance training modes (including: free weight training, machine-based training, bodyweight training, elastic band training, and mixed training) in comparison to each other or to a control condition, focusing on traditional maximal strength outcomes in older individuals. RESULTS: This NMA includes 102 trials involving 4,754 community-dwelling seniors with a mean age of 70 ± 4 years (range 63-87 years of age). All of the included resistance training modalities yield moderate to large positive effects on strength when compared to a "no intervention" control condition. Machine-based training {standardized mean difference (SMD) = 1.34 (95% confidence interval [CI]: 1.16; 1.52)} elicits the largest effects, followed by free weight (SMD = 1.15 [95% CI: 0.28; 2.03]), elastic band (SMD = 0.93 [95% CI: 0.49; 1.37]), mixed (SMD = 0.88 [95% CI: 0.51; 1.25]), and bodyweight training (SMD = 0.71 [95% CI: 0.16; 1.26]). CONCLUSION: Machine-based training elicits the largest effects with the smallest variance. However, our findings demonstrate that various resistance-training modalities can have large positive effects on strength development in older adults. We suggest that, with adequately chosen load criteria such as training intensity, volume and duration of the training period, the selection of the appropriate resistance training type might depend on individual preference, enjoyability, and practicability.