Currently, I'm exercising 3 days a week (every other day), each day doing 2-3 muscle groups. Currently, my goal is to increase muscle mass. My question is, given my exercise goal, is it better to really stress a given muscle group for a single day and then "ignore" it until next week, or to work out all groups each day, but to a lesser extent?
The answer to your question is yes. Yes, you can do a 2/3/4/5 day split each week. And, yes, you can do a full body workout 2-3 times a week. In fact, I would suggest doing both - just not at the same time.
Most people who go to a gym will do a split routine. Usually a 3 day split involves:
- Day 1 - Legs: hams, quads, calves, glutes
- Day 2 - Push: triceps, chest, shoulders
- Day 3 - Pull: biceps, back
You can also add in core muscles on any or all of those days. Alternately, you can do a full body work out. A workout of this type will involve exercises that engage most of the muscles in your body:
- Bench press
- Clean and press/jerk
You cannot do both these routines at the same time, it would be way too much. You can alternate them however. Do a 3 days split for a couple months, then switch to a full body routine for a while, then back again. This will challenge your body in different ways and will keep you from getting use to your exercises and plateauing.