Why does exercise cause you to gain weight? Is there a biological reason for this, or are you just unlucky?

“People don’t understand that doing exercise is good even if you’re gaining weight. While exercise plays a role in weight control, the other side of the coin is food intake,” explained Corinne Caillaud, a professor of physical activity and digital health at the University of Sydney in Australia.

The professor, quoted by Live Science, considers that when we notice an increase in weight after exerting ourselves doing exercise, it is worth reviewing the quantity and quality of food because the explanation is probably in the daily diet.

Caillaud believes there is nothing wrong with an occasional treat, but suggests that exercise is unlikely to offset the effect of the increased frequency of junk food. In case the diet has not changed, it is likely that other biological peculiarities explain the weight gain.

If you are not used to demanding training and you force your body to do it, you could end up forcing the muscles more than it should, causing micro-tears in the muscle fibers, this causes the body to send nutrients to the muscles to repair these damages. 

According to University Hospitals, this is why muscles tend to ache the day after workouts, leading to muscle growth over time.

According to the Cleveland Clinic, these exercise micro-tears can also cause an inflammatory process, or swelling, due to fluid retention in the body. Another explanation may be the change in the amount of blood in the body.

According to Corinne Caillaud, when you do aerobics, at some point, there may be an increase in blood volume due to the increase in aerobic capacity since these exercises represent a measure of the maximum amount of oxygen that the body can consume while exercising. The muscles need the oxygen that is supplied by the blood, in this way, the more oxygen a person can consume, the better his resistance will be.

While none of these reasons can represent a significant change, Caillaud believes that when all this adds up, the weight gain is likely to be explained, but this should not be a reason to get discouraged and abandon workouts since several of these factors such as fluid retention are not permanent.

Image Credit: GEtty