Impact of current or past physical activity level on functional capacities and body composition among elderly people: a cross-sectional analysis from the YMCA study.

BACKGROUND: Physical activity (PA) is recognized as important predictor of healthy aging. However, the influence of the type of voluntary PA as well as age or sex in this relationship is unclear. Thus, we assess the association between current and past PA level and physical performances among voluntary active older adults.
METHODS: Functional capacities (timed Up and Go, sit-to-stand, alternate step test, unipodal balance, grip strength, knee extension strength, estimated muscle power and VO2 max) as well as body composition (DXA: total and appendicular lean masses (LM; kg), fat mass (FM; %)) were measured. Current and last 5-years PA level (time spent on total, aerobic, resistance and body & mind activities) were assessed using an interview. Multiple regressions, adjusted on age, sex and BMI, were performed to assess the relationship between current or past PA level and physical performances. Sub-group analysis, according to the sex (men/women) or age (< 65 yrs. vs. ≥65 yrs) were performed.
RESULTS: 525 subjects (age:61.7 ± 8.1 yrs.; women:68.9%; BMI:26.4 ± 4.8 kg/m2) were enrolled in this study. After adjustment on confounding factors, total current PA level has positive impact on total FM (β = - 2.09, p = 0004) and balance (β = 0.10; p = 0.05). Moreover, current body & mind activities influence total LBM (β = - 0.22, p = 0.02) and balance (β = 0.17; p = 0.001) whereas resistance activities influence total LBM (β = 0.17; p = 0.05), FM (β = - 0.16; p = 0.04) and sit-to-stand capacities (β = - 0.10; p = 0.05). Globally, these results were more pronounced in women than in men and among people aged over 65 years. Past level of PA has low impact on functional capacities and body composition, regardless of sex. Among people < 65 years, there is no relationship between time spent on total PA and functional capacities or body composition. However, a significant correlation was found between past total PA and balance (r=` 0.19; p = 0.01), alternate-step test (r = 0.24; p = 0.02) and VO2max (r = 0.19; p = 0.02) in people aged over 65 years. More precisely, the past time spent on aerobic and resistance activities influence balance (r = 0.16; p = 0.03 and r = 0.15; p = 0.04, respectively) after 65 yrs. old.
CONCLUSION: Even if physical activity history has little influence on physical aging process, being active is associated with body composition and functional capacities, especially among women aged 65 years and over.