Just started hitting the gym every morning at 5:30 AM. Do 10 - 15 of cardio, try to burn about 150 calories. 50 calories on the treadmill and the other on the elliptical machine greddy started doing back workouts today with lat pull downs, some rowing exercises, and had to stop there. Got about only 4 exercises in, as I'm so out of shape. However, my lower back, right above my butt is hurting. I can't bend over or anything. Is it just muscle soreness?