How much exercise do you really need? It’s a simple question without a simple answer. Some experts say 30 minutes a day is enough. Others insist you need much more. A few argue that the official guidelines are arbitrary.
We’ve gathered insights from four popular books: Exercised by Daniel Lieberman, The Body by Bill Bryson, Keep Sharp by Sanjay Gupta, and The 4-Hour Body by Tim Ferriss. Each author brings a different perspective on what counts as “enough.” We’ll also look at the flip side—when working out becomes too much of a good thing. Read on to explore various approaches to an important question.
Table of contents
How Much Exercise Is “Enough”
When it comes to exercise recommendations, experts offer varying perspectives on the ideal amount of physical activity.
In Exercised, Daniel Lieberman echoes the widely recommended guideline of doing 150 minutes of moderate exercise per week. This guideline comes from several studies demonstrating that more exercise correlates with lower mortality rates, with 150 minutes of moderate exercise or 75 minutes of more challenging exercise showing the same positive health effects. However, Lieberman notes that even small amounts of exercise provide significant benefits, with diminishing returns as the amount increases. So, if you can’t do 150 minutes of exercise per week, it’s still more beneficial to do a little exercise than none at all—and there’s no health-related reason to exercise much more than 150 minutes a week.
(Shortform note: Lieberman’s recommendations are in line with those of other scientists. According to the World Health Organization WHO, adults aged 18 to 64 should get at least 150 minutes of moderate physical activity during the week. However, they believe 150 minutes is a healthy baseline and that it’s beneficial to aim for around 300 minutes of weekly exercise. However, John Ratey, author of Spark, echoes Lieberman’s sentiment that doing something is better than doing nothing. He urges readers not to get discouraged if they can’t reach or maintain their workout goals yet. He argues that the brain and the body are optimized for movement, so the key is to move.)
Similarly, in his book Keep Sharp, Sanjay Gupta says it doesn’t take a lot of exercise to counteract the negative effects of inactivity. Aim for at least 30 minutes of exercise a day, five times a week. However, Gupta claims that, if you want to get the most out of exercise, exercising more than an hour a day is now recommended. This is because, from a historical perspective, humans have usually spent most of their day moving.
(Shortform note: Most health experts and doctors agree that you should exercise at least 30 minutes a day or 150 minutes a week. As Gupta points out, though, ideally you should get more than that. A 2011 study found that the optimal amount of moderate aerobic exercise is around 90 to 100 minutes a day, or around 700 minutes a week. Alternatively, 350 minutes of intense exercise (as opposed to moderate) will also suffice. This may seem like a lot, but, to achieve this, researchers recommend two things: Start at a young age, and find what motivates you.)
Alternative Perspectives
However, not all experts agree on these recommendations. Despite extolling the benefits of exercise, Bill Bryson points out in The Body that there’s no consensus on how much exercise you should get. He says the idea that you should take at least 10,000 steps a day is a baseless myth, and the CDC’s recommendation of 150 minutes of exercise per week is based on what experts think the average person can realistically work into their schedule, not on how much exercise anyone thinks is actually ideal.
Bryson goes on to discuss a study that found that people who spent six or more hours a day sitting down were twice as likely to suffer from heart failure or diabetes and had a higher overall mortality rate than people who spent less than six hours a day seated, regardless of how much exercise they got the rest of the day.
(Shortform note: While many other studies support the idea that sitting for more than six hours a day carries significant health risks, very few support the conclusion that it can’t be alleviated by exercise. Currently, most sources suggest that you can reduce the detrimental effects of prolonged sitting by taking short breaks for walking or other light physical activity every 30 minutes.)
Taking a different approach entirely, in The 4-Hour Body, Tim Ferriss presents his philosophy of using the minimum effective dose to get the outcome you’re looking for at a minimum cost. In the case of exercise, this means keeping your workout to the bare minimum that will allow you to achieve a certain goal, such as losing a certain amount of weight. Ferriss himself was able to achieve his fitness goals by investing a total of only four hours a month in exercise and related activity. Based on his experience, he recommends doing a short workout consisting of three specific exercises twice a week.
Beware of Exercise Addiction
While the experts above focus on getting enough exercise, it’s also important to recognize that too much exercise can be problematic. An article in Psychology Today indicates that an estimated 3% of the general population and 25 to 52% of “long-term endurance athletes” might be addicted to exercise, with the highest rates of addiction occurring in triathletes, runners, and those who have an eating disorder. The article defines exercise addiction as feeling compelled to exercise even when it causes negative social, emotional, or physical consequences. The author cites seven symptoms of exercise addiction but notes that most exercisers can relate to some of these, and this does not necessarily constitute an addiction:
- Tolerance: constantly increasing the amount of exercise needed to feel satisfied
- Withdrawal: negative experiences when someone is not able to exercise
- Intention effect: constantly exercising more than we planned to
- Lack of control: feeling compelled to exercise even when it interferes with other needs and obligations
- Time: exercise taking up more time than is recommended by medical professionals or is healthy for each person
- Interference with other activities
- Continuance: continuing to exercise even while injured, sick, or experiencing other negative outcomes from exercise.
The takeaway from the article is that, while exercise is an important part of a healthy lifestyle, it, like most things, should be practiced in moderation. The article even cites research suggesting that engaging in intense exercise for more than 17 hours a week could be just as unhealthy as not exercising at all!
Putting It All Together
Ultimately, while experts may disagree on the exact amount of exercise needed for optimal health, a few key themes emerge from their recommendations.
- First, doing some exercise is always better than doing none at all. So, even if you can’t meet the commonly cited 150-minute weekly guideline, any amount of physical activity provides meaningful health benefits.
- Second, most experts agree that 150 minutes of moderate exercise per week represents a reasonable baseline for maintaining good health, though some suggest aiming higher for optimal results.
- Third, it’s important to apply moderation and balance activity with rest—sitting for extended periods carries health risks that should be offset with regular movement, but exercising excessively can be just as harmful as not exercising at all.
The best approach is to find an amount of exercise that fits your lifestyle, goals, and physical condition, remembering that consistency and moderation are more important than perfection.
Explore Further
To learn more about the broader context of physical activity and health, check out Shortform’s comprehensive guides to the books these ideas come from:
- The 4-Hour Body by Tim Ferriss
- The Body by Bill Bryson
- Exercised by Daniel Lieberman
- Keep Sharp by Sanjay Gupta
