A little over an hour of strength training every week could be enough to deliver significant long-term health benefits, according to a major new study that tracked more than 147,000 adults for up to three decades.

The research, published in the latest edition of the British Journal of Sports Medicine, found that people who spent between 90 and 120 minutes a week doing muscle-strengthening activities had a lower risk of dying from several major diseases. The findings suggest there may be a "sweet spot" for resistance training — exercises that make muscles work against a force, such as lifting weights, squats, lunges, and press-ups.

Researchers analysed data from three of the world's largest long-running health studies: the Health Professionals Follow-up Study, the Nurses' Health Study, and the Nurses' Health Study II. Together, these studies followed 147,374 participants, including 31,540 men and 115,834 women, over periods ranging from 19 to 30 years.

Participants reported every two years how much time they spent on strength training and aerobic exercise. Aerobic activities include brisk walking, running, swimming, cycling, tennis, stair climbing and other exercises that raise the heart rate.

During the study period, 35,798 participants died. After accounting for factors such as age, weight, smoking habits and overall lifestyle, the researchers found that those performing 90–119 minutes of weekly strength training had a 13% lower risk of death from any cause compared with those who did none.

The benefits appeared even more striking for specific diseases. The same amount of weekly strength training was linked to a 19% lower risk of death from cardiovascular diseases—conditions affecting the heart and blood vessels—and a 27% lower risk of death from neurological diseases, which affect the brain, spinal cord, and nerves.

The researchers found that doing more than 120 minutes of strength training each week did not provide additional survival benefits. For cancer, the greatest reductions were seen at lower levels of strength training, with just one to 59 minutes per week associated with an 18%–21% lower risk of cancer-related death.

The strongest protection, however, came from combining strength training with aerobic exercise. Compared with inactive people, those who maintained high levels of aerobic activity alongside regular resistance training experienced dramatically lower risks of death. In some cases, the reduction reached more than 50%.

The findings build on growing scientific evidence that muscle strength plays a critical role in healthy ageing. Previous research has shown that stronger muscles help maintain balance, mobility, blood glucose control, and independence later in life. Scientists increasingly view muscular tissue not merely as a means of movement but as an active organ that influences metabolism, inflammation, and overall health.

The study has limitations. Because participants reported their exercise habits, some inaccuracies may have occurred. The research was also observational, meaning it can identify links but cannot prove that strength training directly caused the lower death rates. The researchers also lacked detailed information on exercise intensity, session length and activities such as Pilates or callisthenics.

Nevertheless, the authors conclude: “Our findings on different dose-response relationships between long-term resistance training and all-cause and cause-specific mortality suggest that different amounts of resistance training may be needed to optimise benefits across outcomes.”

They added: “The observed pattern that adding resistance training further reduced mortality risk across all levels of aerobic activity up to 45 MET hours/week supports current recommendations encouraging both types of activity to maximise mortality benefits.”

At a time when sedentary lifestyles are becoming increasingly common across the world, the findings offer a powerful reminder that maintaining muscle strength may be just as important as keeping the heart active. For many people, the path to better health may not require hours in the gym but rather a consistent commitment to moving, lifting and staying strong throughout life.