Advanced Move: Plank with Arm Lift
Get into the plank position (toes and forearms on the floor, body lifted). Your body should form a straight line (A). Brace your abs and carefully shift your weight to your right forearm. Extend your left arm in front of you (B) and hold for 3 to 10 seconds. Slowly bring your arm back in. Repeat with the right arm. That's 1 rep. Do 2 or 3 sets of 5 to 10 reps, resting for 1 minute between sets.
Advanced Move: Side Plank with Rotation
In a right-side plank position (A), brace your abs and reach your left hand toward the ceiling (B). Slowly tuck your left arm under your body and twist forward until your torso is almost parallel to the floor (C). Return to the side plank. That's 1 rep. Do 2 or 3 sets of 5 to 10 reps on each side, resting for 1 minute between sets.
Advanced Move: Hip-Thigh Raise
Lie on your back with your right knee bent and your left leg extended. Rest your arms on the floor, palms up, at shoulder level with your hips about 2 inches off the floor (A). Raise your hips to form a straight line from your shoulders to your left foot (B). Hold for 2 counts, then return to start. That's 1 rep. Do 10 to 15 reps on each side. To make it harder, cross your arms over your chest.
Advanced Move: Reverse Lunge With Single-Arm Press
Grab a 5- to 15-pound dumbbell in your left hand and hold it up next to your left shoulder, palm facing in (A). Step backward with your left foot and lower your body until your knees are bent 90 degrees (your left knee should nearly touch the floor) while pressing the dumbbell directly over your shoulder without bending or leaning at the waist (B). Lower the weight back to the starting position as you push quickly back to standing. That's 1 rep. Do 10 to 15, then switch sides.