Duarte Martins, AlexandreBatalha, NunoFernandes, OrlandoOliveira, RafaelGonçalves, BrunoBrito, João Paulo2026-04-082026-04-082026Duarte Martins, A., Batalha, N., Fernandes, O. Oliveira, R., Gonçalves, B., Brito, J.P. (2026). The role of physical activity levels in retaining high-speed resistance training effects on body composition: a 1-year follow-up in older adults. Sport Sci Health 22, 135. https://doi.org/10.1007/s11332-026-01715-8http://hdl.handle.net/10400.15/6074Purpose This study evaluated the influence of physical activity (PA) on the retention of body composition effects achieved through a 16-week high-speed resistance training (HSRT) program over a 1-year follow-up period. Methods Forty independent older adults participated in the supervised 16-week HSRT program. After the intervention ended, participants were encouraged to maintain high PA levels. At the 1-year follow-up, 36 participants completed the assessments and were divided into the light activity group (LAG, N = 20, age 70.00 ± 3.66 years) and the moderate-to-vigorous activity group (MVAG, N = 16, age 68.50 ± 2.09 years). Body composition ( InBody® S10), PA levels (International Physical Activity Questionnaire), and anthropometric measurements were assessed at four time points. Results Significant time effects were observed for several body composition parameters over the 1-year follow-up period, with large effect sizes. Specifically, MVAG revealed significant declines in weight (p = 0.002, dunb = −0.22), body mass index (p = 0.002, dunb = −0.30), and fat mass (%) (p = 0.028, dunb = −0.30) from post-intervention to the 1-year follow-up. Conversely, LAG demonstrated significant reductions in fat-free mass (p = 0.018, dunb = −0.14), muscle mass (p = 0.010, dunb = −0.15), and lean mass (p = 0.014, dunb = −0.14) from pre-intervention to the 6-month follow-up (p < 0.001, dunb = −0.18), with body cell mass also presenting significant declines from post-intervention to the 1-year follow-up (p = 0.035, dunb = −0.13). Despite an overall decline, PA remained relatively higher than pre-intervention, particularly for total weekly activity (minutes) and energy expenditure from moderate-to-vigorous PA. Conclusions This study highlights the benefits of engaging in at least moderate PA activities for retaining the effects achieved on a previous exercise program, particularly reductions in fat mass.engagingmuscleadiposityhealthy lifestyleexerciseresearch articlehttps://doi.org/10.1007/s11332-026-01715-8