Resistance exercise using relatively heavy loads (≥70% of 1-repetition maximum) is undeniably effective for increasing muscle mass and strength and improving physical performance.[1][2][3] However, some individuals are apprehensive about lifting heavy loads due to the risk of injury — particularly when performed without oversight from a personal trainer — while others don’t have access to a gym. Fortunately, emerging evidence suggests that lifting relatively light loads (approximately 35%–50% of 1-repetition maximum) exerts similar benefits,[4][5] particularly when each set is performed to volitional fatigue.
This suggests that meaningful improvements in muscle mass, strength, and physical performance can be achieved by performing resistance exercise using one’s own body weight or with minimal equipment (e.g., ankle weights, elastic bands), as long as the individual is exerting a high degree of effort during their workouts.
It’s recommended that from midlife on, adults interested in healthy muscle aging perform resistance exercise at least twice per week.[4] The program should be progressive in nature (i.e., there is an increase in the number of repetitions performed or the amount of load lifted over time) and each workout should comprise a full-body approach with multiple sets (about 2–4) performed per exercise.[2]