Is responsiveness of elderly individuals to resistance training related to habitual nutritional intake? An exploratory analysis of a randomized controlled trial

Purpose: This study investigated the relationship between habitual nutritional intake and the responsiveness of elderly individuals to resistance training. Methods: Nineteen participants (66.0 ± 4.5 years) completed body composition (dual-energy X-ray absorptiometry), functional capacity (timed-up-and-go, stair ascent, and stair descent), and neuromuscular tests (5-repetition maximum and countermovement jump) before and after a 9-week resistance training intervention. Habitual nutritional intake was evaluated at the beginning, middle, and end of the intervention. Participants were also divided into two groups based on their protein intake (low protein group 1.2 g/kg). Results: Total Kcaloric and protein intake explained ~ 21–44% of the functional capacity improvements, while total Kcaloric and carbohydrate intake explained ~ 21–27% of the change in lean mass. Participants with high protein intake showed greater percentage improvement for timed-up-and-go (− 10.7 ± 4.9% and 0.4 ± 7.4%) and stair ascent (− 11.4 ± 7.6% and − 3.2 ± 5.3%) versus those with lower protein intake. Conclusion: Nutritional intake influenced individual responsiveness to resistance training in the elderly. Older adults with higher Kcaloric, protein, and carbohydrate intake presented greater improvement in functional capacity and lean mass following resistance training.