Background: In terms of motivation and long-term adherence, low-resistance exercise might be more suitable for older adults than high-resistance exercise. However, more data are needed to support this claim.
Objective: The objective was to investigate the effect of low- and high-resistance exercise protocols on long-term adherence and motivation.
Methods: This study was designed as an exploratory 24-week follow-up of a randomized 12-week resistance training intervention. Participants were free to decide whether or not they continued resistance training at their own expense post-intervention. Fifty-six older adults were randomly assigned to HIGH (2 x 10-15 repetitions at 80% of one repetition maximum (1RM)), LOW (1 x 80-100 repetitions at 20% of 1RM), or LOW+ (1 x 60 repetitions at 20% of 1RM + 1 x 10-20 repetitions at 40% 1RM). Motivation, self-efficacy and the perceived barriers for continuing resistance exercise were measured after cessation of each supervised intervention and at follow-up, while long-term adherence was probed retrospectively at follow-up.
Results: Participants reported high levels of self-determined motivation before, during, and after the end of the supervised intervention, with no differences between groups (p > 0.05). Nevertheless, only few participants continued strength training after the intervention: 17% in HIGH, 21% in LOW+ and 11% in LOW (p > 0.05). The most commonly reported barriers for continuing resistance exercise were perceived lack of time (46%), being more interested in other physical activities (40%), seasonal reasons (40%) and financial cost (28%).
Conclusion: The results suggest no difference in long-term adherence after the end of a supervised exercise intervention at high or low external resistances. Long-term adherence was limited despite high levels of self-determined motivation during the interventions. These findings highlight the importance of further research on developing strategies to overcome barriers of older adults to adhere to resistance exercise without supervision.