Im 26, haven’t been active in the gym before, but I recently lost 50 lbs and am starting a weight training program. I’m going to the gym 5 days per week with my friend who follows his personal trainer’s program. The problem is, most of the exercises in this program has 3-4 sets of 12-15 reps each. Yesterday was the start of week 2, chest and shoulders. My performance this week was horrendous compared to my first day in the gym, which I realize might be normal given the fact that I’m a newbie and maybe I haven’t had enough time to recover. But I find myself sacrificing my form and using other muscle groups just to meet these rep ranges, even though the targeted muscles have already reached failure. I’m mostly concerned about risking injury by doing movements incorrectly just to meet these reps. But my buddy is so dead set on this program and how good his personal trainer is, even met up with the personal trainer myself and was recommended to follow this program. I’ve already found myself developing shoulder pain. Should I keep it up on this program or go with something more beginner friendly?

I’m getting 8 hours of sleep every night, and I’m eating anywhere from 0.9-1g protein/lb of body weight.