A 24-week online lifestyle intervention combining twice-weekly resistance training and personalized protein intake advice is associated with a 15.49-pound increase in knee extension one-repetition maximum and a 1.16-second reduction in repeated chair rise time among healthy adults aged 55 and older.

When muscles are worked against resistance, they experience tension that triggers internal signals to build more muscle protein. Eating more protein, especially amino acids like leucine, adds more building blocks and turns on the same signals. This causes muscle fibers to grow thicker and stronger. Thicker muscles produce more force, making it easier to lift weight and stand up from a chair quickly.