Cut Down on Cardio
"I was exercising so hard that I began to lose weight," says Lautner. Sound great? Not if you normally have trouble building muscle mass. When it's combined with weight training, cardio saps strength and limits muscle growth, especially if you spin your wheels for longer than 20 minutes before or after lifting, according to researchers at Stephen F. Austin State University in Texas. So be careful not to overdo it. "If you're trying to gain lean mass, focus on weight-lifting with the proper technique and the right plan," Yuam says.
Source: Men's Health