You need a calorie surplus of about 200 to 400 calories to be able to build muscle. For reference, that's about an extra serving of pasta or fiveounces of steak. These extra calories provide the much needed energy you need to push through grueling workouts and heavy sets. They also power the bodily processes that generate muscle synthesis.

A fitness expert explains the 6 most common mistakes that prevent muscle building. Plus, 6 tips to build muscle and achieve your dream physique.