Regular resistance training (RT) has many health benefits for middle-aged and older adults, including improvements in muscular strength, bone health, body composition and metabolic health. Additionally, strength appears to be inversely associated with risk of premature death. National guidelines recommend that older and diabetic individuals engage in RT with exercises targeting all major muscle groups 2–3 times per week with a minimum of one set of 8–12 repetitions per exercise. However, only 27 percent of Americans aged 45–64 years and 25 percent of those aged ≥65 years report engaging in RT at least two days per week, and only 5 percent in those age groups report exercising two days per week and training all seven major muscle groups. Given the health benefits of RT and the low prevalence rates, the development and testing of RT promotion interventions are needed.
[Photo: Dr. David Williams]
This study by Dr. David Williams, and Brown University colleagues, examines psychosocial mediators of the effects of high vs. low-dose resistance training maintenance interventions among older, overweight, and pre-diabetic adults. Participants completed a three-month supervised RT initiation phase and were subsequently randomised to high- or low-dose six-month unsupervised RT maintenance interventions, followed by a six-month no-contact phase.
The study tested several social cognitive constructs as putative mediators of the effects of high vs. low-dose RT maintenance interventions on continuation of RT behaviour among pre-diabetic older adults. Overall, mean changes in putative mediators suggests a natural tendency for stagnation or even slight decreases in these social cognitive variables from the end of the intensive supervised 12-week RT programme through the maintenance intervention, during which time mean frequency of RT behaviour also decreased to some extent. However, there was adequate variability in changes in the putative mediators among the sample of participants to allow for testing of action theory and conceptual theory. Tests of action theory revealed that the additional components in the high-dose RT maintenance intervention led to more positive changes in behavioural expectations, self-regulation and perceived satisfaction, with effect sizes in the small to moderate range. Tests of conceptual theory revealed that variability in changes during the maintenance intervention in behavioural expectation, self-regulation, RT strategies, perceived satisfaction and behavioural intention was predictive of RT behaviour at the end of the intervention and at 12-month follow up. In addition to the consistent effects across most of the targeted mediators, the effect sizes range from approaching moderate effects to large effects.
These findings are consistent with previous research showing similar social cognitive constructs to be predictive of RT behaviour. The present findings suggest that if an RT intervention can promote positive changes in these variables, including attenuation of naturally occurring decreases, it is likely to lead to better maintenance of RT behavior.
Study published in May in Psychology & Health.