Reps: 15 on each leg
How to do it: Stand with feet together, holding dumbbells. Cross your right leg back behind your left on an angle and bend both knees about 90 degrees, reaching your arms down on either side of your left leg. Stand up out of your lunge and tap the ball of your right foot on the inside of your left heel.
Form tip: Keep most of your weight in your front leg as you lunge, and make sure you push your hips back so that your front knee stays (almost) behind your toes as it bends.
