Effectiveness of a Diet and Resistance Exercise Intervention on Muscle Health in Older Adults: ProMuscle in Practice

Abstract

ObjectivesClinical studies show that resistance exercise and a protein-rich diet can counteract the age-related decline of muscle mass, strength, and physical performance. The aim of the ProMuscle in Practice study was to test effectiveness of a resistance exercise and dietary protein intervention for older adults implemented in a real-life setting. DesignA randomized controlled multicenter intervention study. Setting and ParticipantsOne hundred sixty-eight community-dwelling older adults were included (age 75 ± 6 years). A 12-week intensive support intervention including progressive resistance exercise supervised by a physiotherapist and dietitian guidance on increasing protein intake was followed by a voluntary 12-week moderate support intervention to continue the adapted lifestyle pattern. The control group received no intervention. MethodsCompliance was measured through attendance lists and 3-day food records. Physical functioning, leg strength (3-repetition maximum, knee extension strength), lean body mass [(LBM) dual-energy X-ray absorptiometry], and quality of life (5-level EQ-5D) were measured at baseline, and after 12 and 24 weeks. Differences in change between groups were assessed with linear mixed model analysis. ResultsThe intervention group increased protein intake and attended 83.6% of the training sessions. Short Physical Performance Battery score slightly increased in intervention participants [from 10.1 (95% confidence interval 9.7–10.5) to 10.4 (10.0–10.8) at week 12 and 10.6 (10.2–10.9) at week 24], where control participants decreased (time × treatment interactions, P < .05). Improvements in intervention group compared with controls were also observed for Timed Up-and-Go, strength and LBM at both time points (time × treatment interactions, P < .05). No difference between groups was found for the 6-Minute Walking Test, activities of daily living, and quality of life. Conclusions and ImplicationsProMuscle in Practice was effective on improving muscle strength and LBM, with small changes in the composite function score in community-dwelling older adults in a real-life setting. Further research should explore feasibility of real-life implementation, as well as improving long-term compliance.