Exercising, Eating Right, and GAINING WEIGHT?! It’s NOT Muscle Growth!

 I hear this from new clients all the time: “I’ve been eating well, working out hard, and I gained two pounds this week!” This is a common phenomenon, particularly at the beginning of a weight loss endeavor. The canned fitness professional response is, “Oh! You must be gaining muscle! Keep at it!” Before my personal trainer friends jump down my throat, I’ve supplied this response more times than I can count. However, after some research, I discovered I was sorely mistaken. Dare I say….WRONG!? *Gulp*

Working out indeed builds muscle, but it is unlikely, nay, darn near impossible, that a beginner’s weight gain is caused by muscle growth alone. Even an experienced weightlifter can only gain about 1%-1.5% of their total body weight in muscle per month.1 For example, a 200 pound man will typically only gain 2 to 2.5 lbs. of muscle in an entire month, even with a heavy lifting program designed to build muscle mass! This debunks the myth that my new client’s weight gain is caused by muscle growth. Instead, here are the most likely culprits:

Glycogen Storage The body stores carbohydrates in the form of glycogen in the liver and muscular tissue, which can then be easily converted into energy to fuel physical activity. With an increase in aerobic activity, a new exerciser’s body becomes more adept at storing glycogen for future use. 2 For every single gram of glycogen stored, three grams of water are stored as well.2 Therefore, this increased ability to store glycogen may initially cause a 2-4 pound weight gain.2

Delayed Onset Muscle Soreness (DOMS) Delayed onset muscle soreness, or DOMS, is the fancy, scientific term for the soreness you feel 24 to 48 hours after a hard workout. Basically, this soreness is a result of microscopic tears and tissue breakdown caused by a tough exercise session. This causes the body to rebuild and repair tissues, making them stronger and better able to handle tough workouts in the future. Unfortunately, these little tears can also cause inflammation of the muscle tissue, resulting in up to 3-4 lbs. of fluid retention.3

You’re “Fueled Up” When adopting healthier habits, you may be drinking a lot more water and eating more fibrous foods than you did in the past. This extra water and fiber (which holds water) residing in your body (and especially your intestines) can cause a slight weight gain.

Still Eating Too Many Calories You’ve probably heard the old adage, “You can’t out-exercise a bad diet”. Unfortunately, it’s true. Furthermore, exercise increases hunger, often leading new exercisers to eat more calories than usual. This extra calorie intake may prevent fat loss or even cause weight gain.

Here’s the moral of the story: don’t rely solely on the scale to judge progress. Physiological adaptations to exercise can cause weight gain, but don’t be disturbed! If you continue exercising and eating healthfully (increasing energy ouput and decreasing energy intake), the scale will eventually go down. In the meantime, take solace in the fact that you are getting healthier each and every day. Keep it up!


  1. Obadike, O. Ask the ripped dude. Bodybuilding.com Website. http://www.bodybuilding.com/fun/ask-the-ripped-dude-how-much-muscle-can-i-put-on-naturally.html. Published November 9, 2015.
  2. Titchenal A, Dobbs J. Exercise program can result in quick weight gain. Nutrition ATC: A Resource for Health and Fitness Professionals. http://www.nutritionatc.hawaii.edu/HO/2002/135.htm. Published January 9, 2002.
  3. Johnson C. Why the scale goes up when you start a new workout plan. Sparkpeople Website. http://www.sparkpeople.com/blog/blog.asp?post=why_the_scale_goes_up_when_you_start_a_new_workout_plan. Published January 18, 2010.



2 thoughts on “Exercising, Eating Right, and GAINING WEIGHT?! It’s NOT Muscle Growth!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s