Abstract
This retrospective cohort study examined the relationship between self-reported participation in flexibility and muscular strengthening activities and the development of functional limitation (i.e., once an individual has difficulty with or becomes unable to perform activities of daily living). Data were obtained from 1318 adults (mean age 49.5 ± 9.7 years; 98.7% Caucasian; 14.9% female) enrolled in the Aerobics Center Longitudinal Study from 1979 to 2004 and free of functional limitation at baseline. Mail-back health surveys were used to prospectively determine incident functional limitation. Participation in muscle-strengthening and flexibility activities was assessed via self-report. Adjusted logistic regression analyses were used to determine the odds ratios (OR) and corresponding 95% confidence intervals for developing functional limitation during follow-up based on participation in general and specific categories of flexibility ('Stretching', 'Calisthenics', or 'Exercise Class') and muscle-strengthening activities ('Calisthenics', 'Free Weights', 'Weight Training Machines', or 'Other'). Overall, 42.6% of the sample reported incident functional limitation. After adjusting for potential confounders (e.g., age, sex, cardiometabolic risk factors), those who reported performing muscle-strengthening activities in general (n = 685) were at lower risk of developing functional limitation [OR = 0.79 (0.63-1.00)]. In addition, the specific flexibility activities of stretching (n = 491) and calisthenics (n = 122) were associated with 24% and 38% decreased odds of incident functional limitation, respectively. General muscle-strengthening, stretching, and calisthenics activities are prospectively associated with decreased risk of incident functional limitation in generally healthy, middle-aged and older adults. Thus, both public health and rehabilitation programs should highlight the importance of flexibility and muscle-strengthening activities during adulthood to help preserve functional capacity.