The Health Benefits of Exercise Don't Depend on Weight Loss

One of the biggest misconceptions about exercise is that it causes weight loss.

This gets especially bad with kids – you can’t spend five minutes in a discussion about childhood obesity before someone starts lamenting that Kids These Days Just Don’t Play Outside Like they Used To, and if we all just went back to the days of playing tag instead of sitting in front of the TV, childhood obesity would disappear.

But that’s just not the case. There’s no convincing evidence that increasing exercise without changing diet will reduce rates of childhood or adult obesity. In study after study, exercise alone, without change in diet, doesn’t cause any significant weight loss, because exercise alone just can’t make up for a lousy diet.

Exercise does have all kinds of benefits for weight loss as an add-on to a healthy diet, and it might make weight loss easier to maintain (by preserving muscle mass and metabolic rate), but it can’t make up for eating poorly. Getting kids to go outside and play doesn’t help if they come inside afterwards and have a Coke and a Cosmic Brownie as a snack, pizza for dinner, and ice cream for dessert. And the same goes for adults; exercise alone has failed again and again to produce any appreciable weight loss. If you’re not eating well, you won’t lose weight by adding exercise, and if you are eating well, any weight loss will probably come from your diet, not from whatever exercise you’re also doing.

But that doesn’t make exercise a waste of time! Even without causing an ounce of weight loss, exercise can provide all kinds of health-related benefits, including some of the benefits you might be trying to get by losing weight. And focusing on those benefits may also make it easier and more pleasant to stick with.

Exercise Doesn’t Need to Cause Weight Loss to Improve Health

Even if exercise causes absolutely no weight loss at all, it still has health benefits – including a lot of the health benefits that people try to get from losing weight. (In fact, as any bodybuilder or powerlifter trying to put on muscle can tell you, sometimes they actually come along with weight gain.)

Anti-Inflammatory, Cognitive, Cardiovascular, and Metabolic Benefits of Exercise Without Weight Loss

Ready to take a dive into the wonderful world of research?

• This review looked at cardiovascular health, and found that exercise can significantly reduce a person’s risk of cardiovascular disease even without causing any notable weight loss. A lot of people try to lose weight to improve their heart health, but exercise can reduce dangerous visceral fat (fat around the organs) and waist circumference, and improve cardiovascular fitness without changing any numbers on the scale.
• This study looked at obese, frail elderly people, which is a group incredibly vulnerable to all kinds of chronic diseases. The researchers divided the people into three groups: a weight-loss diet group, an exercise group, and a diet + exercise group. After 1 year of that, they measured their cognitive function and quality of life. The exercise group didn’t lose any significant amount of weight (which you’d expect, considering that exercise without a change in diet is ineffective for weight loss). But without causing any weight loss, the exercise group improved cognitive function as much as the diet + exercise group, and way better than the diet alone. The diet barely added any benefit. The vast majority of the benefits came from exercise, and they came totally independent of any weight loss.
• A review of exercise in children found that exercise improves insulin sensitivity and metabolic health independently of calorie restriction or weight change. It’s worth noting that the evidence for inflammation in children is more conflicting.
• This study looked at the effects of 12 weeks of exercise in obese, middle-aged men with liver problems. Fatty liver disease is strongly associated with obesity, and a lot of people think that weight loss will help improve their liver health, but this study showed that weight loss wasn’t actually necessary. The exercise barely caused any weight loss, but it helped improve insulin sensitivity, reduce liver inflammation, and generally improve various different markers of liver health just as well as a weight-loss diet.
• Another review questioned the evidence that the anti-inflammatory benefits of exercise for adults come from weight loss. There’s actually quite a lot of evidence that exercise is anti-inflammatory “independent of fatness” (as the study puts it).
• For women, exercise has multiple benefits for breast cancer protection independent of weight loss.

This review gave an interesting overview of how exercise and “ad libitum nutrient-dense diets” (read: no calorie restriction) can benefit people with obesity. Even when they don’t cause any weight loss, these interventions can…

“improve fat and glucose metabolism, and insulin action; enhance endothelial function; have favorable changes in blood lipids, lipoproteins, and hemostatic factors; and reduce blood pressure, postprandial lipemia and glycemia, and proinflammatory markers.”

Not too shabby!

The Motivational Benefits of Exercising for Health, not Weight Loss

This study also found a practical benefit from understanding the non-weight-related benefits of exercise. Thinking of exercise as beneficial for reasons other than weight helped people actually stick to exercising more regularly – about 3 more hours/week than people who just heard about how it would help them lose weight.

That makes perfect sense: people who are exercising for weight loss are probably likely to get discouraged and give up when the exercise doesn’t cause weight loss (which exercise alone doesn’t do – are you tired of hearing that yet? Because it’s still true!). But people who are focused on benefits that exercise actually does bring won’t get discouraged because they aren’t expecting it to magically cause weight loss in the first place.

Exercising for health also frees you up to do whatever you like doing, even if it doesn’t burn the most calories. And in the long run, people who can do what they like will be much more consistent about working out than people who think their only “good” option is something they hate. Can’t stand jogging? Skip it and deadlift instead. Hate weightlifting too? Go for a swim. Sure, it burns fewer calories, but calorie burn isn’t what you were going for anyway, so who cares?

Summing it Up

It’s time to break the link between exercise and weight loss. Exercise has many health benefits totally independent of weight loss, which is great because exercise typically doesn’t cause any significant amount of weight loss in the first place.

Exercise isn’t “pointless” if you’re not losing weight from it, and the idea that thin people “don’t need to exercise” is plain ridiculous: unless those thin people are exempt from the normal rules of human biology, they can benefit from exercise just like everyone else. If you want to lose weight, the kitchen is the place to start. But if you want to improve your health, consider a trip to the gym – to do something that you enjoy and can keep up in the long run.