Want to punch up your training? Learn to work the bag.

Here’s your tutorial from Jason Strout, co-owner of Church Street Boxing Gym in New York City, where Lennox Lewis has sparred.

1 Fight in your weight class

If the bag wobbles from side to side after you throw a punch, go with a heavier bag. You’ll have a better workout.

2 Adjust your stance

Stand at arm’s length from the bag with your feet shoulder-width apart for balance. If you’re right-handed, place your left foot slightly in front of your right so your left heel and right toe are aligned. Stay on your toes and keep your knees slightly bent – that’s how you’ll spring into your punches.

3 Throw a powerful punch

Aim for the middle of the bag; otherwise it’ll spin and you’ll risk hurting your wrists. When you jab, keep your shoulder, elbow, wrist and knuckles aligned. After the punch, pull your arm back just as quickly to boost your cardio workout. Be sure to add crosses and hooks. Work in small combinations: jab-cross, jab-cross-hook, jab-hook-cross. Keep the routine basic, but focus on your form.

4 Do more with less

Pound away for 10 minutes and you’ll work up a sweat, but you’ll also miss out on a more intense workout: short, quick, powerful punch combinations for three-minute rounds. Rest 30 seconds between rounds; do five rounds total. For an added workout, jump rope between sets to keep your cardio up.