Elderly obese women display the greatest improvement in stair climbing performance after a 3-week body mass reduction program

OBJECTIVE: To investigate whether stair climbing performance and body composition are similarly affected by a body mass reduction (BMR) program in obese individuals of different gender, age and body mass index (BMI) level. DESIGN: Longitudinal, clinical intervention study entailing energy-restricted diet (5023-7535 kJ/day), nutritional education, psychological counselling and moderate physical activity (indoor cycling, outdoor walking, gymnastics routines, five sessions/week) during a 3-week period. SUBJECTS: A total of 466 male and 807 female subjects categorized as a function of gender, age (< vs >/=50 y) and BMI (< vs >/=40 kg/m(2)). MEASUREMENTS: Body mass, stair climbing time and power before and after the BMR program. Fat-free mass and fat mass were also evaluated by bioimpedance analysis, in a representative subgroup of 160 patients, to evaluate the relation between fat-free mass and power output. RESULTS: Body mass, fat-free mass and fat mass significantly decreased following the BMR program (P<0.001), with male subjects reducing body mass and fat-free mass more than and fat mass less than the female subjects. Stair climbing time decreased (P<0.001) and therefore anaerobic power significantly increased 9.7% after the treatment. The greatest improvement in stair climbing performance was observed in obese women aged >/=50 y. Significant inverse correlations were found between initial power or fat-free mass level and respective percent increases (R=-0.35/-0.37, P<0.001) and between BMR-induced percent changes in body mass and power (R=-0.13, P<0.001). CONCLUSION: Subjects with the lowest baseline level in stair climbing performance (and probably with the lowest amount of fat-free mass), that is, obese women aged more than 50 y, obtained the largest enhancement after the 3-week BMR program, likely improving overall functional capacities and resulting in greater independence during daily-living activities in such a population.