Well I have baseball every single day from 2:30 PM-6:00 PM..Well I come home relax and Im done by like 7:30 PM. I don't really have time to weight lift my that time because for 1 I have a elbow injury and 2 I wouldn't have enough time. If I just run on my thread mill for like 30 minutes and did a bunch of ab excercises would that make me lose muscle of would this be good for my body?