Exercise Has Many Health Benefits, but Weight Loss Isn't Really One of Them

You’ve been working your butt off for weeks at the gym. You’ve got the sweat and sore muscles to prove it. But, for some reason, the scale hasn’t budged. Or worse, the number you see on the dial has been creeping up. 

If weight loss, at its most basic level, is a matter of calories in and calories out, it's reasonable to assume it's possible to burn off those extra calories in the gym — and lose weight — without making any diet modifications. But science has begun to show that we might want to examine this mindset a bit more skeptically.

While you may not want to cancel your gym membership just yet, the inescapable truth of weight loss is that exercise doesn't compensate for a poor diet. Find out how many calories you really need to lose weight and what the true benefits of exercise are.

Regular exercise can prevent or help manage a slew of health issues — from cancer to heart disease to Alzheimer’s and arthritis. But losing a lot of weight isn't chief among exercise's many benefits.

Instead, focusing on the first part of the “calories in, calories out" equation may be the most effective approach to slimming down.

“Typically, people are able to lose much more from caloric restriction than from exercise simply because the caloric expenditure with your typical exercise regime — 30 minutes most days of the week — doesn’t translate to very much weight loss,” says Jennifer Kuk, a kinesiologist at York University in Toronto, over email.

Read More: The Flexible Dieting Lifestyle Could be a Liberating Approach for Losing Weight

Determining how many calories to consume for weight loss has become more complex than the old "3,500 calories per pound" rule. Modern research suggests this approach oversimplifies the process as it doesn't account for how an individual's metabolism adapts over time. Instead, a more dynamic approach is recommended, where calorie needs are adjusted as the body changes.

"The reason dieting may be more effective than just exercise is because exercising would take a ton more activity and effort to create a 500- to 700-calorie deficit,” says Yasi Ansari, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics, in an email.

To put this in perspective, a 155-pound person would burn roughly 500 calories from an hour of high-impact aerobics or by walking for 90 minutes at a rate of 4.5 mph.

So, in other words, don't expect much from those quick trips to the gym. Someone who started exercising 30 minutes almost every day would probably lose about a pound over the course of a month, Kuk says. For most people trying to lose weight, that would be downright disappointing. (It’s no wonder that half of all new gym customers drop off by the end of January.)

Read More: The Myth of Negative Calorie Foods

What’s worse than experiencing little or no weight loss while exercising? Gaining weight. That's right: Sometimes an exercise program can cause the opposite of its intended effect.

One study from a team of Arizona State University researchers tracked 81 sedentary, overweight women over a 12-week exercise program that consisted of 30 minutes of brisk treadmill walking three times per week. Surprisingly, most of the women didn’t lose pounds by becoming more active — and more than half of them gained weight.

Another study from researchers at Louisiana State University followed 200 overweight men and women enrolled in a supervised aerobic exercise program over the course of six months. The study found that the participants ended up compensating for the calories lost to working out by eating more. As a result, many participants didn't lose weight, or they gained it.

“Some people will find that they are hungrier with exercise and that their body will try to protect themselves against weight loss by increasing hunger, and they lose less weight than expected,” Kuk says. “This is more commonly reported in women.”  

Read More: What Factors Matter Most For Weight Loss?

It is technically possible to lose weight simply by working out — albeit with caveats.

Some studies have demonstrated that exercise alone can create a calorie deficit that’s large enough to generate weight loss. But for the average person, the required intensity and time commitment — about an hour every day — can be difficult to stick to.

“Most [people] will have problems exercising one hour per day at a moderate intensity every day to equal the weight loss you would get from your typical diet,” Kuk says.

Most health professionals recommend implementing both approaches — calorie control and exercise — when losing weight. And this is probably pretty sound advice.

But where exercise might be more helpful is keeping weight off once we've lost it. A recent study from the University of Colorado Anschutz Health and Wellness Center revealed that exercise plays a greater role than diet in sustaining substantial weight loss.

Read More: Why Walking Might Be One of the Best Exercises For Health

No matter your weight or fitness goals, remember that the health benefits of a balanced diet and exercise regime go far beyond a number on the scale.

“Eating better and exercise can improve your health even if you don’t lose a single pound,” Kuk says.

A 2011 study found that adopting a healthy diet and moderate exercise can reduce obese people's risk of cardiovascular disease and diabetes, regardless of whether they lost weight or not. 

And, it's a controversial idea, but some researchers think you can be "fat but fit." In other words, your fitness ability, regardless of weight, might play a major role in overall health.

So, if you find yourself frustrated the next time you step on the scale, Kuk recommends asking yourself why you're trying to lose weight in the first place.

“Many try to lose weight because of the clear bias and stigma in our society … I believe that for most people who are trying to lose weight, society is the problem, not the individual. This is not to say that we should not try to eat well or exercise regularly … but this is a message for all of us, not just those with weight obesity,” Kuk says. 

Read More: This Is How Exercise Affects the Brain

Moderate exercise is physical activity that isn't too light but isn't too strenuous either. When you're doing moderate exercise, you're working at a level that uses three to almost six times the energy you would use when resting. Examples of moderate-intensity exercises include walking briskly at a pace of 4 mph, engaging in heavy cleaning activities like washing windows or vacuuming, bicycling at a light effort of 10-12 mph, playing recreational badminton, and playing doubles tennis. 

If you're looking to lose weight, aerobic exercise (like running, walking, or cycling) might be your best bet. Research shows people who did aerobic exercise for about 12 miles each week lost more weight compared to those who did weight training three times a week. After 8 months, those doing aerobic activities lost around 4 lbs, while the weight training group lost about 2 lbs. 

Weight loss can be challenging due to several reasons. According to the Journal of Health, Population, and Nutrition, genetics, health conditions like hypothyroidism or PCOS, and lifestyle factors such as lack of sleep and stress may all affect how well you lose weight. Also, how closely you follow your diet plan and external factors like environmental pollution and social support play a role. Tailoring your weight loss strategy to address these issues can help.

Starting an exercise program gradually is important, especially if you're inactive. Begin with short sessions of 5-10 minutes and slowly increase the duration. This approach prevents injuries, helps your body adjust, and reduces the risk of heart disease. Short, manageable workouts can effectively lower blood pressure and improve heart health without overwhelming you.

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• Science Daily. Exercise alone does not help in losing weight

• Harvard Health Medical School. Calories burned in 30 minutes for people of three different weights

• The Journal of Strength and Conditioning Research. Predictors of Fat Mass Changes in Response to Aerobic Exercise Training in Women

• The Pennington Biomedical Research Center. You Exercise Faithfully... Why Aren’t You Losing More Weight?

• Reuters. Interval training burns off more pounds than jogging or cycling

• American Association for the Advancement of Science. CU Anschutz study reveals exercise is more critical than diet to maintain weight loss

• The Physician and sportsmedicine. Exercise and diet, independent of weight loss, improve cardiometabolic risk profile in overweight and obese individuals

• British Journal of Sports Medicine. The Fat but Fit paradox: what we know and don’t know about it

• Korean journal of family medicine. An Overview of Current Physical Activity Recommendations in Primary Care

• Harvard School of Public Health. Examples of Moderate and Vigorous Physical Activity

• Diabetes spectrum : a publication of the American Diabetes Association. Role of Physical Activity for Weight Loss and Weight Maintenance

• Journal of Health, Population and Nutrition. What could be the reasons for not losing weight even after following a weight loss program?

• Harvard Medical School. Easing into exercise