Effects of Strength Training versus Power Training on Physical Performance in Prefrail Community-Dwelling Older Adults

Background: It has been unclear which training mode is most effective and feasible for improving physical performance in the risk group of prefrail community-dwelling older adults. Objective: The purpose of the present study was to compare the effects of strength training (ST) versus power training (PT) on functional performance in prefrail older adults. This study was registered at clinicaltrials.gov as NCT00783159. Methods: 69 community-dwelling older adults (>65 years) who were prefrail according to the definition of Fried were included in a 12-week exercise program. The participants were randomized into an ST group, a PT group and a control group. All participants were supplemented with vitamin D-3 orally before entering the intervention period. The primary outcome was the global score on the Short Physical Performance Battery (SPPB). Secondary outcomes were muscle power, appendicular lean mass (aLM) measured by dual energy X-ray absorptiometry and self-reported functional deficits (Short Form of the Late-Life Function and Disability Instrument, SF-LLFDI). Results: Regarding changes in the SPPB score during the intervention, significant heterogeneity between the groups was observed (p = 0.023). In pair-wise comparisons, participants in both training groups significantly (PT: p = 0.012, ST: 0.009) increased their SPPB score (PT: Delta(mean) = 0.8, ST: Delta(mean) = 1.0) compared to the control group, with no statistical difference among training groups (p = 0.301). No statistical differences were found in changes in aLM (p = 0.769), muscle power (p = 0.308) and SF-LLFDI (p = 0.623) between the groups. Muscle power significantly increased (p = 0.017) under vitamin D3 intake. Conclusions: In prefrail community-dwelling adults, PT is not superior to ST, although both training modes resulted in significant improvements in physical performance. With regard to dropout rates, ST appears to be advantageous compared to PT. The high prevalence of vitamin D3 deficiency and the slight improvement of physical performance under vitamin D-3 supplementation among study participants underline the relevance of this approach in physical exercise interventions. Copyright (C) 2011 S. Karger AG, Basel