Working Out and Gaining Weight: What Is Normal?

After starting a GLP-1 medication regimen or undergoing bariatric surgery, you will undoubtedly be told that exercise, especially strength training, is crucial for improving excess weight-related conditions, enhancing aesthetics, and achieving long-term weight loss. However, some patients—especially those who haven’t worked out in a while—become frustrated when they see the scale go up instead of down.

While this is common and completely normal, many patients perceive it as a sign of failure and ultimately quit their exercise routine. So, how do you know if the weight gain is a normal part of the process or if it’s a sign that something isn’t working?

Why We Gain Weight When Exercising

Weight gain is normal after beginning an exercise regimen, especially in the first few weeks. It primarily results from muscle growth when performing strength training or bodyweight exercises.

Strength training builds muscle, which is much denser and thus heavier than fat. You may gain weight initially as your body adapts to this new strength training regimen. Fortunately, as muscle mass increases and fat decreases over time, the weight drops—often quite rapidly.

How Can I Ensure My Weight Gain Is Normal?

We get it—no matter how much reassurance you receive, seeing the number on the scale go up can be discouraging. So, here’s how to tell whether your weight gain is normal or something to be concerned about:

1. Weight gain should not be rapid or sustained.
   Yes, you might weigh two pounds more today than yesterday, but a rapid and consistent upward trend over weeks or months is not normal. If your weight steadily increases over a prolonged period, consult your surgeon or weight loss specialist.
2. Measure both your weight and waist size.
   If your weight gain is due to exercise, your waist size should not increase—in fact, it should decrease over time. Strength training does not increase waist circumference, so if your waistline is growing, another factor might be at play.
3. Muscle soreness is a good sign.
   Experiencing muscle soreness after workouts strongly indicates your muscles are growing. Here’s why: Small micro-tears form in the muscle fibers when you lift significant weight. The muscles retain water and nutrients to heal, temporarily increasing your body weight.
4. The weight gain should reverse.
   Depending on your body and how vigorously you exercise, you should begin to see the weight gain reverse within several days and see some good weight loss results within a few weeks.

Track Your Calories

Calorie tracking is crucial when starting a new exercise regimen. When you burn more calories, you might feel hungrier after workouts and may negate some of the benefits of exercise. This is especially true after a challenging cardio workout or when you’ve been working out in the heat.

Hydration is Key

If you don’t drink enough water before, during, or after your workout, your body may misinterpret thirst as hunger, leading to excess calorie consumption. If you eat more, you might be undoing your progress because you “feel” hungry but don’t truly need the fuel.

The Bottom Line

As any successful weight loss patient knows, weight loss is not linear. Managing the frustration of fluctuations in the weight loss journey is just as important as following your postoperative diet and exercise program.

For patients committed to working out, self-checks can help determine whether weight gain is normal or if they need to adjust their diet or exercise routine. But if you have concerns, don’t hesitate to let us know. Whether during a follow-up appointment or at one of our support groups, we’re here to help you stay on track and achieve long-term success.