4. Sit squats
Stand with your back to the seat of a chair, feet hip-width apart, legs straight but not locked. Hold your baby to your chest with your hands. Contract your abdominals so your tailbone points toward the floor and squeeze shoulder blades together [A]. Keeping your back straight and your body weight back toward your heels, bend your knees, lowering your torso into a squat as if to sit down. Your torso will lean forward slightly [B]. When the backs of your thighs barely touch the chair, straighten legs to starting position; repeat. Do 1 set of 12 reps, building to 2 or 3 sets of 12. Strengthens quadriceps, hamstrings and buttocks.
Sit on the edge of a chair with feet wider than hip width. With baby in your arms, abs tight and chest lifted, lean forward from hips, keeping back straight and lowering baby toward floor [A]. Keeping abs tight and back straight, return to a vertical seated position, bringing baby up with you [B]. Repeat. Do 1 set of 8 reps, building to 2 sets of 8. Strengthens back and legs.