2. No-Hands Reverse Crunch
Instead of keeping arms at sides, where they can help abs, anchor them overhead to activate more belly muscles. Lie faceup with arms overhead and hands grasping a heavy piece of furniture or railing. Raise feet into the air with legs bent. Contract abs, press back into floor, and lift hips off floor. Exhale as you lift; inhale as you lower. *Prevention Fitness Lab testers averaged 21 reps per set.
MAKE IT EASIER
Do the move with arms down at sides.
MAKE IT HARDER
Straighten Legs.
TIPS
Feel the contraction in abs, not in back or legs.
Tilt pelvis.
Think of lifting up instead of pulling knees toward chest.
STOP WHEN...
You can't lift hips off floor without jerking.
Neck and shoulders are tense.
3. V Crunch
This exercise gets your upper and lower body moving simultaneously to recruit the maximum number of muscle fibers in your midsection. Balance on tailbone with legs bent, feet off floor, and arms bent at sides. Make sure back is straight and chest is lifted. Lean back and extend arms and legs, then pull back to start position. *Prevention Fitness Lab testers averaged 11 reps per set.
MAKE IT EASIER
Grasp sides of thighs with hands.
MAKE IT HARDER
Hold a 3- to 5-pound dumbbell in each hand.
TIPS
Eyes gaze straight forward; keep chin parallel to floor.
Don't let back curve or shoulders rise toward ears.
STOP WHEN...
You can't keep arms or legs up.
You can't keep chest lifted.
Back or neck starts to hurt.
4. Side Plank
Static balancing moves like this one are challenging because your deepest abs work really hard to hold your core in midair. Do them after crunches to ensure complete fatigue—and firm abs from every angle. Lie on right side, elbow beneath shoulder, feet stacked, left hand on hip. Contract abs to lift hip and leg off floor. Hold until fatigued, noting your time. Do 3 sets before switching sides.
*Prevention Fitness Lab testers averaged 19 seconds per side for each set.
MAKE IT EASIER
Bend legs and balance on bottom knee and side of lower leg.
MAKE IT HARDER
Straighten top arm toward sky.
TIPS
Keep head, neck, torso, hips, and legs all in one straight line.
Don't sink into shoulder—press elbow into floor and lift torso.
STOP WHEN...
Hip is sagging toward floor.
Neck, shoulder, or back hurts.
You can't keep body in line.
THE EXPERT
Tony Caterisano, PhD, exercise scientist and professor in the department of health sciences at Furman University, designed this workout.