Background & AimsAging frequently causes changes in body composition, such as a loss of strength and muscular mass and an increase in fat mass. Exercise training programs have been suggested as effective strategies to mitigate or prevent age-related declines in body composition. Therefore, this study examined the effects of a sixteen-week High-Speed Resistance Training (HSRT) program on body composition parameters in community-dwelling independent older adults. MethodsThe present clinical trial included 79 older adults, who were divided into two groups: intervention group (IG, N=40, age, 68.50 ± 3.54 years; weight, 68.65 ± 11.36 kg) and control group (CG, N=39, age, 72.08 ± 5.89 years; weight, 67.04 ± 10.69 kg). IG performed the supervised HSRT for 16 weeks, with 3 sessions per week of 60–70min, each session of 5–6 exercises, 2–3 sets, and 6–10 reps/exercise while CG did not perform any exercise training program. Body composition parameters were assessed using a multifrequency tetrapolar bioelectrical impedance analyzer (InBody® S10). The level of physical activity and the dietary intake were evaluated by the International Physical Activity Questionnaire (IPAQ-SF) and the Food Frequency Questionnaire, respectively. Statistical analyses were performed using the analysis of covariance (ANCOVA), and effect size (Cohen's dunbiased). ResultsThe analysis showed significant effects of the group factor for IG on phase angle (F(1)=14.39, p<0.001, η2p=0.159). Additionally, results from Δ changes (post- minus pre-values) revealed small and medium effects in favor to IG for body cell mass (t(77)=1.21, p=0.230, dunb=0.27 [-0.17, 0.71]) and phase angle (t(77)=2.82, p=0.006, dunb=0.63 [0.18, 1.08]), respectively. ConclusionsThe HSRT could effectively prevent the decline in cellular health and cell integrity in older adults, as evidenced by the significant improvements in the phase angle. RegistrationClinicaltrial.gov (ID: NCT05586087).