Too much exercise wears out your heart
Short answerNo
On this page
No, not for living longer. In 661,137 adults, even 10 times the guideline’s minimum still went with 31% lower risk of death than doing nothing, and in 122,007 adults who took a treadmill test, the fittest lived longest. The real debate is about heart rhythm in people who do years of endurance sport.
What we’d do
Don’t hold back for fear of wearing out your heart. For almost everyone, too little exercise is the bigger risk by far. Build up gradually, and if you do train for many hours a week, year after year, take a racing, fluttering or irregular heartbeat to a doctor. Chest pain during exercise means stop, every time.
If you remember three things
- More stayed better than none. 10 times the minimum was still 31% lower risk than none, with “no evidence of harm”.
- Fitness showed no ceiling. In the treadmill study, the fittest group did best of all, including people over 70.
- Athletes do get more of one rhythm problem. In a 2021 review, athletes had about 2.5 times the odds of atrial fibrillation of non-athletes.
Why it sounds true
It’s an old worry. A 2001 history of exercise science starts with Hippocrates, who advised more than 2,000 years ago that exercise was good for health, “though not too much of it”. Every few years a headline about a runner who collapsed brings it back.
The studies seem to give it some cover too. In the biggest pooled study, the drop in risk of death peaked at 3 to 5 times the guideline’s minimum (39% lower than doing nothing) and was smaller at 10 times or more (31%). In 1986, a study of 16,936 Harvard alumni found death rates fell steadily as their weekly exercise rose, and then “increased slightly” past the highest level. It’s easy to see those bends as harm.
A picture from daily life
Think of a savings account where the interest rate drops once your balance passes a certain amount. Past that point each extra dollar earns less, and it still never starts costing you money.
Exercise behaves like that in the big studies. Past about 5 times the minimum, each extra hour adds little or nothing, and the people doing the most were still better off than the people doing nothing.
What the studies found
10 times the minimum
661,137 adults in six US and European studies, median 14 years. Arem and colleagues, JAMA Internal Medicine, 2015
At 10 or more times the minimum, about 25 hours of brisk activity a week, risk of death was 31% lower than doing nothing. The authors found “no evidence of harm” and wrote that doctors “do not need to discourage adults who already participate in high-activity levels.”
Few people were that active, so the estimate is less precise (22% to 41% lower).
30 years of health professionals
116,221 US adults, 30 years. Lee and colleagues, Circulation, 2022
300 or more hard minutes a week, or 600 or more brisk ones, “did not clearly show further lower” risk of death, “or harm”.
Self-reported exercise, repeated over the years.
The fittest lived longest
122,007 adults who did a treadmill test, about 8 years. Mandsager and colleagues, JAMA Network Open, 2018
Risk of death fell with every step up in fitness, with “no observed upper limit of benefit”. The elite group did better than the high group, even among people 70 and older and people with high blood pressure.
Fitness was measured once, in patients sent for a treadmill test.
What about heart rhythm in athletes?
The case for worry
Athletes get more atrial fibrillation. In a 2021 review of studies that compared athletes with non-athletes, athletes had about 2.46 times the odds of atrial fibrillation, an irregular heart rhythm. The risk was highest in younger athletes and in mixed sports.
What it does and doesn’t mean
It’s a real finding about years of competitive sport. It’s far past the hours on this site, and in the studies of death, the most active and the fittest groups still did better than inactive people. The review’s authors called for studies by training and competition history to pin down who is at risk.
Where the myth has a point
Doing too much too soon is a real problem, just a different one. The US guideline’s safety advice is to “increase physical activity gradually over time”, and inactive people should “start low and go slow”. And anyone with chest pain, fainting or a racing, irregular heartbeat during exercise should stop and get checked, whatever their training. Who should check with a doctor first?
7 sources
- Arem H and others, Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship, JAMA Internal Medicine, 2015europepmc.org
- Lee DH and others, Long-term leisure-time physical activity intensity and all-cause and cause-specific mortality: a prospective cohort of US adults, Circulation, 2022europepmc.org
- Mandsager K and others, Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing, JAMA Network Open, 2018europepmc.org
- Newman W and others, Risk of atrial fibrillation in athletes: a systematic review and meta-analysis, British Journal of Sports Medicine, 2021europepmc.org
- Paffenbarger RS, Blair SN and Lee IM, A history of physical activity, cardiovascular health and longevity: the scientific contributions of Jeremy N Morris, International Journal of Epidemiology, 2001europepmc.org
- Paffenbarger RS and others, Physical activity, all-cause mortality, and longevity of college alumni, New England Journal of Medicine, 1986europepmc.org
- US Department of Health and Human Services, Physical Activity Guidelines for Americans, 2nd edition, executive summary, 2018odphp.health.gov
