Associations of Physical Activity with Body Composition, Functional Fitness, and Isokinetic Strength in Older Adults

(1) Introduction: Physical activity is considered a key factor in maintaining functional health during aging; however, its relationship with objective measures of physical performance remains unclear. (2) Methods: A cross-sectional study was conducted with 63 community-dwelling older adults (70.4 ± 6.6 years; 35.7 ± 6.5% body fat). Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ), and participants were classified into activity levels. Body composition was evaluated using bioelectrical impedance analysis. Functional fitness was assessed through standardized tests, including lower-limb strength, Timed Up and Go (TUG), and the 2 min step test (2MST). Isokinetic strength of the knee extensors and flexors was measured at 60°/s and 180°/s. Non-parametric tests, Spearman correlations, and linear regression analyses were performed; (3) Results: No significant differences were observed between IPAQ categories for body fat percentage, TUG performance, lower-limb strength, or aerobic capacity (all p > 0.05). Correlations between MET values and physical or functional variables were weak (ρ ranging from −0.07 to 0.18). (4) Conclusions: Self-reported physical activity was not associated with objective measures of physical function in older adults. These findings highlight the importance of incorporating objective assessments of physical performance when evaluating functional health in this population.