If you’re working with clients who are pumping iron to build muscle, be sure they have plenty of protein on their plates. A study in The Journal of Nutrition found that a daily protein intake equaling 2 grams per kilogram of body weight maximized lean body mass anabolism (i.e., muscle growth) in seven resistance-trained men (ages 21–27). So if the goal is to increase muscle mass, a 170-pound person could benefit from eating up to 154 g of protein. That’s in the upper range of current protein guidelines for athletes.

It’s yet to be determined whether women and older individuals need as much protein as the men in this study.

See also: Female Athletes May Need to Pump Up the Protein