Just 17 minutes a day of weight-training lowers risk of death from heart disease and dementia
Less than two hours per week lifting weights – just 17 minutes per day – is enough to significantly reduce one’s risk of death by any cause.
In a new study, weight-lifting was linked to a roughly 13 percent lower risk of all-cause mortality, as well as a reduced risk of dying from heart disease and dying from dementia.
Those who combined resistance training with aerobic exercise, such as walking or dancing, saw the greatest reduction in the risk of death.
Researchers said that perhaps the most striking and most overlooked finding was the connection between weight training and neurological death, particularly from dementia, which is estimated to affect seven million Americans.
The heart benefits of resistance training may come down to arterial stiffness. While intense lifting temporarily stiffens arteries, regular long-term training does the opposite, especially in middle-aged and older adults more likely to be stricken with heart disease that affects 30 million Americans.
For cancer, the study found a different pattern. Only lower amounts of weight training of less than one hour per week were tied to a reduced risk of cancer death, while high amounts had no effect.
Heavy weight training increases levels of insulin-like growth factor 1. High levels of this hormone have been linked to an increased risk of certain cancers, including colorectal, breast and prostate cancer.
Doing more than two hours per week did not provide additional benefit in any area. The protective effect plateaued, meaning that for most people, the goal is achievable at just three 30-minute sessions per week.
A achievable weekly dose of weight training was tied to a 13 percent lower risk of death overall and specifically lower odds of dying from heart disease or dementia (stock)
The research, published in the British Journal of Sports Medicine, followed 150,000 Americans from three long-term Harvard studies for up to 30 years. During that time, nearly 36,000 participants died.
Researchers used repeated questionnaires to track how much time participants spent lifting weights or using resistance machines.
They also measured aerobic exercise like walking, running and swimming.
Compared with people who did no weight training, those who lifted for 90 to 119 minutes per week had a 13 percent lower risk of dying from any cause.
The findings were even more striking for specific causes of death.
The same amount of resistance training was linked to a 19 percent lower risk of death from heart disease and a 27 percent lower risk of death from neurological diseases, mostly dementia.
For cancer death, only lower amounts of weight training were tied to a reduced risk; 1 to 29 minutes per week was associated with a nine percent lower risk, and 30 to 59 minutes per week was associated with a 12 percent lower risk.
Perhaps the most intriguing finding involved brain health. While the heart benefits of exercise are well known, far less research has looked at whether lifting weights might lower the risk of dying from dementia.
Each colored bar represents a group of people based on how much they lifted weights each week: none, up to 1 hour, 1 to 2 hours, or more than 2 hours. The vertical axis shows the percentage of people in each weight-training group. People who did the most weight training were also the ones who did the most aerobic exercise. For example, among those who lifted more than 2 hours per week, very few were in the lowest aerobic category
This study adds important evidence, though the authors caution that reverse causation is possible in that people in early stages of dementia often become less active years before diagnosis.
The study also examined how weight training and aerobic exercise work together.
Aerobic activity alone — at least 2.5 hours per week of moderate exercise like brisk walking or one hour and 25 minutes per week of higher-intensity exercise like jogging — lowered death risk by 26 to 43 percent depending on how much people did.
But the lowest risk of death from any cause was seen in those who did both.
People who got 30 to 45 MET-hours of aerobic activity per week, such as roughly two to three hours of brisk walking or jogging, plus 60 to 119 minutes of weight training, had a 45 percent lower risk of death compared with those who did little of either.
Even at very high levels of moderate to vigorous aerobic activity at more than seven and a half hours per week, or roughly four hours of vigorous exercise, adding weight training still appeared to offer some benefit.
However, once aerobic activity reached an even higher threshold of roughly 7.5 hours of vigorous exercise or about 15 hours of moderate exercise, resistance training alone did not further reduce mortality risk.
At that extreme level, aerobic activity alone already achieves the maximum benefit.
The line drops modestly and steadily from 0 to about 90 minutes, then flattens and rises slightly at higher levels. The greatest reduction, a 27 percent lower risk, occurred at 90 to 119 minutes per week
These two charts show how different amounts of weekly weight training affected the risk of death from all causes and from heart disease
The study had limitations. Weight training was self-reported, though the use of repeated measurements over decades helps reduce error.
Participants were mostly white health professionals, so findings may not apply to all populations.
The researchers also did not measure intensity or specific exercises.
Still, the message for most people is that a modest amount of weight training — about 20 minutes most days of the week — combined with regular aerobic exercise may offer the best protection against early death. And no one needs to spend hours in the gym.
For the millions of Americans who already walk or run regularly, adding just one or two short weight sessions each week could make a meaningful difference in long-term health and potentially in how long they live.
