Hey, Health Coach: Why Am I Gaining Weight When I’m Working Out?

First, congratulations on your goal to run a 10K. Big objectives like that can help you create healthy habits that have the potential to extend well beyond race day, especially if you enjoy the training process.

You don’t mention if your pseudonym, Not Fast Enough, refers to not running or not losing weight fast enough, but I gather it might be a little of both.

You’re much more likely to stick with a workout routine if you’re getting the payoff you want. If you’re disappointed or don’t feel good, you could be tempted to quit as soon as you achieve your short-term goal—in this case, the 10K.

Lots of people gain weight when they first start a new workout routine, and there are physiological reasons for it. Fortunately, many of them are short-lived.

Micro-tears

When you first begin exercising or start a new sport, your muscles often feel sore for 24 to 48 hours after a workout due to tiny tears created by healthy strain on muscle fibers. As those tears heal, the muscle gets stronger, which is a good thing. However, in order to heal, your body needs to retain extra water. Muscles are already approximately 76% water, so that healing process can make a noticeable difference on the scale.

Inflammation

That same process of stress and recovery can also create inflammation after an intense bout of exercise. Again, water retention helps your body heal after a hard workout, but research shows exercising regularly can reduce inflammation in the long run.

Glycogen

Glycogen is the energy our muscles use for power. When we exercise more, we need to store more of it in our cells. Glycogen also needs water to fuel the muscle. Each gram of glycogen is stored with at least 3 grams of water. However, with consistent exercise, muscles become more efficient at using glycogen, so they need to store less of it—and less water as well.

Muscle Mass

A month or two after you start exercising, your body composition may begin to change. You will likely gain muscle mass and may begin to lose some fat mass. Muscle weighs more than fat, but it also burns more calories. Closely tracking your weight during this window can be confusing—your clothes may feel looser while the number on the scale stays the same or even goes up a few pounds. How strong or energetic you feel could be a more meaningful measure of your progress at this stage than your weight.

Appetite

Research is mixed on whether exercise increases appetite, but many studies show that exercise actually decreases hunger hormones, especially in the immediate aftermath of a workout. The result is a delay in hunger cues, but over the course of a day, calorie intake often remains the same regardless of whether people exercise. This news may be motivating if your goal is to lose weight. If the amount you’re eating is stable and you’re burning extra calories by running, you could see slow, steady weight loss over time.

However, I do have one note of caution on appetite. Anecdotally, as a coach, I’ve seen lots of people follow long run days with burgers and fries they wouldn’t have eaten otherwise. Lots of factors influence appetite—physical, environmental and psychological. If you’re exercising more than usual, make sure to fuel your body regularly with high-quality carbohydrates, protein and healthy fats. A little goes a long way. You might find a small snack before or after running could help curb overeating later in the day and even give you more power for your workouts.

If the purpose of training for this 10K was weight loss exclusively and you’re gaining instead, I can see how staying motivated could be tough.

I hope the information above makes it clear that your body is functioning exactly as it should. It’s adapting to increased demand, and it needs extra water to do that.

So, what can you do about it?

Give Your Body What It Needs

Drink lots of water, eat frequently to be sure you’re getting all necessary nutrients and prioritize rest and recovery. Our bodies adapt beautifully—if we give them time. Within a few months, your muscles will be stronger and more efficient, and, if your weight is still higher than you would like, you’ll be in a solid position to adjust your diet, stress levels or anything else that could be contributing to the number on the scale.

Focus on Benefits Beyond Weight Loss

Take note of other reasons you decided to train for this race. Maybe you wanted better cardiovascular health, mental clarity, a sense of accomplishment, time alone or with a running buddy or structure in your days and weeks. Maybe you were just curious to see how far and fast you can run.

As your body acclimates to your new workout routine, don’t forget to measure success with a variety of metrics—not just the number on the scale. If you can do that, you’ll have a lot to keep you going while you wait for your body to catch up with your new lifestyle.

In the meantime, I’m cheering you on. Thanks for sending such a great question. You very well may have inspired some readers of this column to lace up and hit the road, too.

“Hey, Health Coach” is for informational purposes only and should not substitute for professional psychological or medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions about your personal situation, health or medical condition.

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