I'm Exercising But Still Gaining Weight. What To Do?

When you combine physical activity with a diet, it's fairly common to see your weight loss stagnate, or you might even gain some weight. Why is this? Can exercising make you gain weight? Should I stop doing sports while dieting?
Decathlon Malaysia
September 7, 2021

The vast majority of people come to the gym with the same simple goal in mind: exercise to lose weight, or to simply stop gaining any. However, many people are surprised to find out that they gain weight when adding sport/fitness to their diet. What causes this? Do sport activities make you lose weight or gain weight? How do you speed up your weight loss? Julie, your Domyos sports coach, explains.


When you start doing workouts, you build muscle and therefore start gaining muscle mass. This means that you are going to weigh more. However, this in no way hinders your body from reducing its fat mass. In fact, you will slim down even as you gain a bit more weight. The same holds true for those practicing frequent or intense fitness activities: they may experience weight gain, since exercise increases your muscle mass, which weighs more than fat does. The muscle is a heavy tissue, which is why you might see an increase of 1, 2 or even 3 kg on the scale.


What you need to bear in mind is that exercise helps reduce the amount of fat in your body when combined with a balanced diet. Exercise also helps to stabilize your weight, your diet, and your physical and mental well-being. Physical exercise increases your body's expending of energy, which is critical to losing weight and/or to keeping one's weight down after a diet. It assists in burning fat mass, which is used as fuel when the body exerts itself. It also decreases the risk of diabetes by lowering the body's resistance to insulin, which lowers sugar levels in the blood (glycemia). Lastly, fitness/sports activities are excellent for your cardiovascular well-being, as they reduce stress on the arteries and increase your body's level of good cholesterol.


To be convinced, you can measure your body's impedance, which tells you the percentage of muscle and fat tissues that your body is made up of. Certain high-tech weight scales can tell you this value. Health care professionals can also measure this through a bioelectrical impedance analysis (BIA), which uses electrodes placed on various parts of your body.


To lose weight, add variety to your fitness routine, and most importantly, combine muscle strengthening workouts with cardio training fitness activities. On the one hand, muscle strengthening will help to raise your body's metabolism, which means your body will burn more calories while exercising and while at rest. On the other hand, cardio training will trigger lipolysis, that is, the consumption of fat mass as energy fuel. Ideally, you should do a 1 hour workout session (50% muscle strength and 50% cardio) 3 times a week.

Don't forget to eat a healthy, balanced diet (1/3 each of proteins, vegetables, and carbs). Eat fruit to give your body plenty of vitamins, and cut out snacking between meals. If you're consuming more calories than your body needs (an average of 2000 calories a day for women and 2500 for men), you will have a hard time making up the difference through burning energy in your workouts. Exercising does not mean that you can eat more fat without weight gain. Exercise on its own is not an excuse to give in to your appetite for treats. If you want to slim down, you have to curb the excess.

So there you have it — it is possible that your body will gain weight as you do sports. This is explained through an increase in your body's muscle mass, in other words, the growth of your muscles. This doesn't mean you're not losing fat mass, but rather that your body is rebalancing itself. To get thin more quickly, go for the winning one-two punch: muscle strengthening + cardio training. Lastly, remember that a rich or fatty diet can negate your efforts to lose weight. So at meal times, make "moderation" your motto!