Promotion of muscle-strengthening exercise for public health: a systematic review of real-life interventions in healthy adults

Abstract

Objectives: Few adults adhere to muscle-strengthening exerciseguidelines (≥ 2 days/week), showing an urgent need to increase this physical activity mode in the general population. We aimed to evaluate the effectiveness of real-life interventions in promoting muscle-strengthening exercise among healthy adults. Design: A systematic review (PROSPERO CRD42020146423). Methods: Studies were eligible if they reported behavioral outcomes of a 'real-life' intervention promoting muscle strengthening exercise in healthy, community-dwelling adults. Study selection, data extraction, and quality assessment were completed, and behavior change techniques were coded. Results: Sixty-nine unique studies (10 to 3507 participants) were included; 36 were randomized controlled trials. Five studies were rated as strong, 12 as moderate, and 52 as weak. Of the 54 studies providing session attendance , rates ranged between 10 and 100 %, with only seven studies showing rates below 60 %. Only nine studies assessed and reported actual engagement in muscle-strengthening exercise. Most randomized controlled trials (70.0 %) showed an improvement in functional performance. Moderate evidence was found for no change in blood pressure and body-mass index. However, conflicting evidence was found for other outcomes. The most commonly used behavior change techniques (51 were reported) were instruction on how to perform the behavior (91.3 %), behavioral practice/rehearsal (76.8 %), and demonstration of the behavior (76.8 %). Conclusions: This review suggests that participation in real-life interventions promoting muscle-strengthening exercise is substantial. However, behavioral outcomes related to the actual engagement in muscle-strengthening exercise were hardly reported. As such, from a public health perspective, there is limited evidence on how to best promote muscle-strengthening exercise in healthy populations and more high-quality intervention studies are needed. © 20XX Practical implications • Participation in community-based interventions promoting muscle-strengthening exercise in healthy populations is substantial. • The most commonly used behavior change techniques were instruction, practice/rehearsal, and demonstration. • Few studies reported actual engagement in MSE, leaving limited evidence on how to increase uptake and maintenance of MSE.