Is Weight Gain a Possibility While Strength Training?

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When you start lifting weights, you may wonder how your body will adjust or change. This will vary from person to person, but ultimately, you should notice your body growing stronger. You may also notice the number on the scale increasing slightly—this is normal and should not deter you from strength training. While your weight may be technically going up, your body fat percentage will likely decrease. Here is what you need to know about strength training and weight gain.

Is it Normal to Gain Weight When Lifting Weights?

There are a variety of reasons you might gain weight when you start lifting weights, including building lean muscle mass and water weight or inflammatory weight gain from the healing process. It's important to remember that the number on the scale is not reflective of the intensity of your workouts, your body composition, or your level of fitness.


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Key Reasons for Weight Gain

There are several different reasons that you may notice an increase in weight when you begin strength training. In some cases, the higher number means that you are making progress.

Increased Muscle Mass

Weight training can cause weight gain due to an increase in muscle mass. If you strength train regularly and improve your fitness level, your weight on the scale may increase while your body fat percentage decreases. Muscle is denser than fat and takes up more space.

This switch in body composition happens over months. You can confirm that it is happening by looking in the mirror at the changes in your body, trying on that pair of jeans you have owned since before you started your weight training program, or using a simple body fat percentage calculator.

If your body fat percentage shows more muscle and less fat, then that is the change you are looking for. If your jeans are baggy or loose, or if you look in the mirror and a more muscular person is staring back at you, then your strength training efforts could be causing a bit of an uptick on the scale.

Water Weight

Water can change your weight. Ever notice you weigh less after a sweaty workout session? That loss of sweat can cause a decrease on the scale, just as a salty dinner can cause your weight to increase because your body is retaining water. Your weight can fluctuate due to your water retention versus water loss, and it is not related to your strength training at all. No matter what, stay hydrated all day.


Stress can cause weight gain. When you are under stress from tough workouts or a tough day at the office your body produces the stress hormone cortisol. More cortisol released in the body can cause fluid retention.

Lack of sleep due to stress can make you hungrier too, and you may eat more than you normally do. Make sure you plan some downtime to do the things that recharge you mentally and physically to alleviate some stress. Be sure to take a recovery day during your workout week, so you are not over-exerting your body.

Other Factors

There are many factors that can change your weight such as hormones, stress, diet, water consumption, and your body getting too accustomed to the same old workout. These variables can make your weight can go up and down. Keep making healthy decisions and use tools other than your scale to track your progress.

Weight Loss Benefits of Strength Training

Think of strength training as your long-term solution to weight loss instead of fearing that it will cause weight gain. Strength training offers many health benefits, including an increase in the number of calories burned. The more muscle you have in your body, the more calories you burn every single day. So strength training is the best way to gain muscle mass and lose body fat.

According to the American Council on Exercise, muscle tissue burns more calories than fat tissue, and building muscles costs a lot of energy. As you increase the amount of muscle you have, you will also increase your resting metabolic rate.

3 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Barakat C, Pearson J, Escalante G, Campbell B, De Souza EO. Body recomposition: can trained individuals build muscle and lose fat at the same time?Strength Cond J. 2020;42(5):7-21. doi:10.1519/SSC.0000000000000584

  2. Block JP, He Y, Zaslavsky AM, Ding L, Ayanian JZ. Psychosocial stress and change in weight among US adultsAm J Epidemiol. 2009;170(2):181-192. doi:10.1093/aje/kwp104

  3. American Council on Exercise. Trimming Off the Fat.

By Chris Freytag
Chris Freytag is an ACE-certified group fitness instructor, personal trainer, and health coach. She is also the founder of