American College of Sports Medicine position stand. Resistance training prescription for muscle function, hypertrophy, and physical performance in healthy adults: an overview of reviews

This ACSM position stand is an overview of systematic reviews on how resistance training variables affect muscle strength, size, power, endurance and physical function in healthy adults. It updates ACSM's 2009 stand on progression models in resistance training, which critics had faulted for weak evidence methods.

Compared with no exercise, resistance training improved a wide range of outcomes, including gait speed and balance. Home-based, elastic band, power and circuit training also helped. Only a few prescription choices changed results: heavier loads, full range of motion and more sessions favored strength; higher weekly volume and eccentric overload favored muscle growth; and moderate loads and fast lifting favored power.

Training to failure, equipment type, periodization, time under tension and blood flow restriction did not consistently change outcomes. The authors say their findings support a much broader range of resistance training programs than before, tailored to each person's needs and goals, and they note that resistance training is safe for healthy adults of all ages.