Day Two: Core
Get an exercise ball and rest your knees against it. Grab a medicine ball or small (5 to 10 pound) dumbbells. Extend your arms and legs and repeat for 10 to 15 reps. Add a second set as you get stronger.
Prone Rows (Rhomboids)
Grab two dumbbells (three to five pounds). Lie on your stomach on the ball with your legs straight behind you (balance on your toes).
Start with your arms hanging off the ball and bring elbows toward the ceiling. Hold for one second and slowly lower. Repeat 10 to 15 times, then slowly increase weight and reps.