Am I gaining unusually fast? At the end of May, I was 140 lbs with little muscle mass and I was also pretty weak. I started lifting the last week of May and started bulking the first week of June. Now, I'm 151 lbs and I've put on a good amount of muscle. I've been doing cardio as well. I read that other users were going up 20 or 30 pounds in years and I gained 10 pounds in a month. If it matters I'm 5'8 and African American. 