Can Exercise Make You Fat?


The thought of exercise actually making us fatter is impossible for most people to comprehend. Yet, judging by the continued increase in rates of obesity paralleled with increased rates of gym membership, we are clearly doing something wrong.

What if working out can actually make us gain weight? What if the scenarios below were true?


More Exercise = More Appetite = More Food Consumed

This can eventually lead to two scenarios:

  • More exercise = more appetite = more poor food consumed = more fat
  • OR


  • More exercise = more appetite = more good food consumed = more muscle and less fat
    Judging from my gym experiences, I would say many (if not most) treadmill and stair climber enthusiasts go with scenario number one. I would go as far as assuming that many of these individuals whom are treadmilling to burn the bad calories they ate may actually be better off if they skipped the treadmill altogether. However, would many people be better off if they skipped the gym entirely?

    Is It Better to Skip the Gym?

    The benefits of exercise are well established,1-3 so advising people to skip the gym in an effort to control their appetite would be a tall order. However, exercise must be performed in the face of a quality diet or the benefits will likely have very little effect. In fact, the increase in appetite that often accompanies exercise may be an invitation for some to eat more. That in turn may lead to the incorrect rationalization that the exercise will burn the calories off (this never works as it is nearly impossible to exercise off the extra calories of a poor diet).
    For instance, many athletes and gym rats are generally the most active in the summer, as winters are often plagued with snow and frigid weather that leaves them stuck indoors. These same individuals often eat an incredibly large amount of food throughout the entire summer. However, if the quality of the food never suffers while the calories are increased even above the calories burnt in the gym, these individuals often experience a loss in body fat with a complementary gain in muscle.

    Can We Eat More, Exercise Less, but Still Have a Healthier Body?

    It is somewhat of a chicken or the egg phenomena, as the more one eats, the better his or her workouts are, and vice versa. If we cut calories, we can expect our gym time to suffer. Randomized data actually supports this phenomena, where the quality of our food, and not the calories, clearly affect whether it is turned into muscle or fat.4 Overeating certain foods (not carbohydrates) may actually increase our resting metabolism and give us more energy to exercise, burn fat, and build muscle, leaving us in a healthier state with a better physique and more energy.
    Taking a closer look at the article mentioned above, when individuals were instructed to overeat, they all gained the same amount of body fat, however the metabolism of those who ate a higher protein diet increased significantly, while it went unchanged in the low protein group. Even more interesting, the normal and high protein diet groups gained significantly more muscle than the other group. The point here is not to suggest that we all overeat protein, but more so that actually increasing our calories, if done correctly, can allow us to ramp up our metabolism while gaining muscle. Over-exercising and eating the wrong foods, which commonly plagues many gym members, may have a drastically different and unwanted effect.

    What this paper also screams is that not all calories are created equal when it comes to energy levels, metabolism, and muscle versus fat mass.

    What Does This All Mean?

    While the quality of calories we put in our mouths is always of extreme importance, for those that exercise often, this importance may be raised, the opposite from what most believe as true. Exercise clearly increases appetite for many and if this hunger is quenched with poor food choices, we may not be surprised to experience a decrease in our physique and even a gain in body fat. This is often confusing to those who spend significant time in the gym, but cannot seem to budge the amount of fat on their body, even though they peddle away on the exercise bike or stair climber for hours at a time. They are likely burning the highest number of calories of anyone in the gym; however, if they make poor food choices following their workouts, they will never be able to burn off the excess fat.

    Can You Exercise off Your Calories?

    I generally do not like to speak in absolutes, but the answer to this question is absolutely, positively, 100% not. For instance, I played an hour of soccer during a match earlier this week. I burned approximately 630 calories during my play. This almost offset my pre and post workout meals, which totaled 1000 calories. Soccer also happens to be one of the most metabolically demanding workouts available. If this is not even burning the calories I ate before and after the game, will the drone of a treadmill or stair climber account for the poor food choices made throughout the day? Absolutely not.
    The good news is that if we eat good sources of food, it will provide us with the extra energy to have better workouts, perform better at work and look and feel better overall. Simply cutting our calories to lose weight, especially in the face of exercise, causes our resting metabolism and energy to decline rapidly, as has been shown in research from 30 years ago by Dr. Phinney.5
    So what can you do this summer and fall to stay slim with plenty of muscle and energy?

    CONT’D: Follow the link HERE to continue reading the remainder of the article.


    Subscribe to Caveman Doctor


    1. Borghouts LB, Keizer HA. Exercise and Insulin Sensitivity: A Review. Int J Sports Med. 2000;21(1):1-12. doi:10.1055/s-2000-8847.
    2. Burgomaster KA, Heigenhauser GJF, Gibala MJ. Effect of short-term sprint interval training on human skeletal muscle carbohydrate metabolism during exercise and time-trial performance. J Appl Physiol. 2006;100(6):2041-2047. Available at:
    3. Morris JN, Pollard R, Everitt MG, Chave SPW, Semmence AM. Vigorous Exercise in Leisure-Time: Protection Against Coronary Heart Disease. Lancet. 1980;316(8206):1207-1210. doi:10.1016/s0140-6736(80)92476-9.
    4. Bray GA, Smith SR, de Jonge L, et al. Effect of Dietary Protein Content on Weight Gain, Energy Expenditure, and Body Composition During Overeating. JAMA J Am Med Assoc. 2012;307(1):47-55. doi:10.1001/jama.2011.1918.
    5. Phinney SD, LaGrange BM, O’Connell M, Danforth Jr E. Effects of aerobic exercise on energy expenditure and nitrogen balance during very low calorie dieting. Metabolism. 1988;37(8):758-765. doi:10.1016/0026-0495(88)90011-x.

    © 2015 CDR Health and Nutrition, LLC. All Rights Reserved.

1 Comment

  1. MimiR

    Oh, and I want to add…I dropped my activity that I was doing 10 or so hours a week and got fat. Discovered through an activity tracker that I was at maintenance while fat at 1650 calories a day because I was so sedentary. I cut down on how much I ate temporarily to lose weight, but my sustained weight maintenance? 100% exercise. I like eating 1800+ calories a day, when I can get away with it! I’m much. much happier working out more and eating more. 🙂 Eating only 1650 calories a day and still being fat sucked.


Leave a Comment

Your email address will not be published. Required fields are marked *