Most Americans already know they should do some form of resistance exercise. Most do not — surveys consistently find that fewer than 25 percent of American adults meet current physical activity guidelines for both aerobic and muscle-strengthening activities. One barrier is uncertainty: how much is enough? How much is too much? Does an hour a week matter? Two hours? Five?
A massive new study from Harvard T.H. Chan School of Public Health, published June 2, 2026 in the British Journal of Sports Medicine and widely reported this week, has answered that question with unusual precision — tracking nearly 150,000 American adults across three landmark long-running studies for up to three decades to determine exactly how much weekly strength training is associated with the greatest reduction in risk of death.
