Velocity-based resistance training in institutionalized older adults: protocol for an experimental study with follow-up

Background The effects of velocity-based resistance training (VBRT) in institutionalized older adults remain poorly explored. This protocol aims to describe a study designed to i) analyze the effects of a 9-month VBRT program on skeletal muscle size, muscle function, physical performance, disability, cognitive function and frailty in nursing home residents, ii) compare the impact of different velocity loss (VL) thresholds (10% vs. 20%), and iii) determine the residual effect of the intervention after 6 months exercise cessation. Methods Nursing home residents aged ≥65 years will participate in this experimental study. Participants will complete a 4-week control period followed by a 9-month VBRT program and 6 months of follow-up after exercise cessation. The intervention will consist of VBRT twice a week using the leg press exercise for 9 months. The participants will be randomly assigned to two VL groups: 10% vs. 20% VL, performing n repetitions at 60% of estimated maximal isometric force until reaching their prescribed VL. To minimize training volume differences, the 10% VL group will complete 4 sets, while the 20% VL group will complete 3 sets. Outcomes will include muscle size of rectus femoris and vastus lateralis (ultrasound), muscle function (sit-to-stand muscle power and force-velocity relationship parameters), physical performance (Short Physical Performance Battery and walking tests), disability (Barthel and Lawton Indexes), cognitive function (Mini-Mental State Examination) and frailty (Fried Phenotype and Frailty Trait Scale). The time course of the exercise-induced adaptations will be assessed throughout the study. Discussion We hypothesize that VBRT will exhibit meaningful benefits in muscle size, muscle function, physical performance, disability, cognitive function and frailty among institutionalized older adults, with no significant differences between 10% and 20% VL thresholds. While deconditioning is predictable after 6 months of exercise cessation, the investigated outcomes are expected to remain significantly and positively elevated compared to baseline values. This study will help to identify innovative actions to improve overall health and endorse exercise practice in older adults living in nursing homes. Trial Registration ClinicalTrials.gov , identifier NCT07027397.