Physical exercise has demonstrated efficacy non-pharmacological intervention for positively influencing many parameters related to frailty. Nevertheless, this research was the first investigation into the enduring effects of physical activity and BCAA supplementation on biomarkers, including albumin, in frail and pre-frail older adults living in Portuguese institutions. The outcomes regarding frailty scores demonstrated a decrease in physical frailty among the intervention groups, while the control group experienced an increase. This suggests that a hybrid intervention, which combines physical exercise and complementary nutritional support, is significant in the management of the frailty syndrome. The aim of this study was to examine the effects of multicomponent exercise, supplementation with branched-chain amino acids (BCAAs), and a combination of both on the prevention and reduction of frailty. The study included individuals with an average age of 83 years, who were categorised into four groups: MEP + BCAA (Multicomponent Exercise and BCAA), MEP (Multicomponent Exercise), BCAA (BCAA group), and CG (Control group). Assessments were conducted at four distinct intervals over a period of 40 weeks. These assessments included many domains including frailty, cognition, depression, mood, comorbidities, body mass index, dietary evaluation, physical function, and blood biomarkers. This is achieved through the implementation of a protocol using strength training with elastic resistance, which aims to enhance male participation in this form of exercise. The research determined that a combination of physical activity and nutritional assistance is significant in treating frailty in older individuals residing in institutions.