Functional Fitness and Its Physiological Determinants in Hispanic Older Adults

Background/Purpose: Functional fitness and body composition are key predictors of healthy aging, yet limited research has explored these relationships in Hispanic older adults. The purpose of this study was to examine how physical activity levels, fat-free mass (FFM), relative grip strength, age, and sex influence various measures of functional performance. Methods: A total of 130 Hispanic adults aged 60–80 years participated in this study. Total amount of exercise done per week (METs) was estimated using the international physical activity questionnaire. Functional assessments included the 4-meter walk (4MW), Timed Up and Go (TUG), Chair-stand test (CST), and a grip strength test (RGS). Body composition was measured using dual-energy X-ray absorptiometry (DEXA) to determine total and regional FFM. Correlation analyses were conducted for all subjects, and separately by sex (male, female) and age group (60s, 70s). Results: Across all subjects, 4MW (r = −.227, p = .009) and TUG (r = −.174, p = .048) times were negatively correlated with total METs. Body weight and grip strength were negatively correlated (r = −.405, p < .001), while age was positively associated with TUG time (r = .221, p = .012). Grip strength was also positively correlated with CST performance (r = .229, p = .009). Additionally, total and regional FFM were positively associated with grip strength (r = .410, p < .001). Among males, CST performance was positively correlated with METs (r = .579, p < .001), while 4M (r = −.361, p = .026) and TUG (r = −.364, p = .025) were negatively correlated. Arm FFM showed a positive relationship with grip strength (r = .333, p = .041). In females, age was significantly correlated with all performance measures—positively with 4MW (r = .275, p = .008) and TUG (r = .312, p = .002), and negatively with CST (r = −.265, p = .011) and RGS (r = −.231, p = .027). Grip strength was also positively associated with CST performance (r = .250, p = .016). No significant relationships were observed between METs and performance measures. Among participants in their 60s, total METs were negatively related to 4MW (r = −.260, p = .018), and age was also negatively correlated with 4MW (r = −.261, p = .018). Total FFM was strongly associated with grip strength (r = .455, p < .001). In the 70s group, age was positively correlated with TUG time (r = .420, p = .003). Grip strength was positively correlated with CST performance (r = .318, p = .026) and negatively associated with 4MW (r = −.298, p = .037). Total and regional FFM remained positively related to grip strength (r = .373, p = .008). No significant relationships were observed between METs and performance measures. Conclusion: Physical activity, fat-free mass, relative grip strength, age, and sex present significant, but not fully consistent relationships with functional fitness among Hispanic older adults. Greater physical activity was linked to better mobility reflected by faster 4MW and TUG performance, while higher FFM was consistently associated with greater grip strength across all groups. Although FFM did not demonstrate a direct association with lower-body functional performance, RGS, a variable correlated with FFM, did show a significant relationship with lower-body functionality. This finding highlights its value as a practical indicator of overall functional capability. Age showed the most consistent relationship with slower mobility and reduced strength, particularly among females. Physical activity, grip strength, and fat-free mass are key predictors of overall functional health. These findings showcase the importance of sustaining regular exercise to maintain lean mass, muscular strength, and mobility to preserve functional independence in aging Hispanic populations. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.