How much do I need?

Can you exercise too much?

By GyroscopeUpdated November 14, 20264 sources

Not for a long life. In 661,137 adults, people who did 10 times the US minimum still had 31% lower risk of death than people who did nothing, with no sign of harm. The curve stopped dropping at 3 to 5 times the minimum, so past that point, more is up to you.

Every few years a headline says marathon runners wear out their hearts, and the idea sticks because it sounds like common sense. Too much of most things is bad, so it seems like exercise should be the same. When researchers went looking for that harm in death rates, they didn’t find it. What does exist is too much too soon, the sore, flat, badly slept feeling of training harder than you recover from, and an easy week fixes it.

Where does the benefit stop?

The curve works like a dimmer switch. The first turn takes a dark room to light. After a point, more turning barely changes what you see, and it never makes the room darker. Here are the numbers from the 2015 pooled study, six US and European cohorts followed for a median of 14 years:

The researchers set out to find the upper limit, the point where more exercise stops helping or starts hurting. They found where it stopped helping, at 3 to 5 times the minimum. At 10 times, risk was still 31% lower than doing nothing, about the same as just meeting the minimum.

Did other studies find harm?

A 2022 study of 116,221 US health professionals filled in activity questionnaires up to 15 times over 30 years. Past 300 hard minutes or 600 brisk minutes a week, death rates didn’t clearly fall any further, and they didn’t rise either.

Fitness tells the same story. In 122,007 people who took a treadmill test at the Cleveland Clinic, the least fit quarter had about 5 times the death rate of the fittest 2% over the next 8 years. The researchers saw no upper limit of benefit, including in older patients. These were people sent for a treadmill test, so probably a bit less healthy than average, and like the others, it’s a study of what people chose to do.

When is it too much?

Training harder than you recover from shows up within days. You’re sore longer, you sleep worse, your legs feel heavy and your times slow down. A lower HRV the morning after a hard session is part of the same picture, and hrv.guide explains why your HRV is low after a workout. Rest fixes it.

Chest pain, dizziness, an irregular heartbeat or breathlessness you can’t explain are different. MedlinePlus says to stop what you’re doing and rest, and chest pain or pressure means calling 911. See what to do if you get chest pain while exercising.