Step up your stair-climber game with these trainer tips (as if it wasn’t already hard enough)?

You—and your legs—might know the ins and outs of treadmills and elliptical machines, but there’s another way to tap into heart-pumping cardio at the gym that you might be forgetting all about: StairMaster workouts. If you’ve felt intimidated by stepping up your fitness program in the past, fear no more.

Here, Adam Friedman, a celebrity trainer in Venice, California, has a primer for how to use the StairMaster and make the most of your stair-climber workouts.

1. Maintain Your Posture

To put strain on the right parts of your body—the glutes and hamstrings instead of your back—slow down and get your posture right. “When you’re hunched over, you’re putting strain on your back and turning down your glutes,” he says. (Not to mention the fact that you’re probably placing a good portion of your weight on the stair-climber machine.) It’s OK to hinge forward a bit at the hips—a move that’ll engage the glutes even more—as long as you keep your spine straight, he says.

2. Don’t Hold On

You know the move: a fellow gym goer is climbing up the cascading stairs, gripping the sides of the machine for dear life. “That’s not helping your body work harder—it’s cheating,” says Friedman. If you’re feeling off-balance, lightly grasping the sides will help you get steady. But don’t rely on them to hold you up. That reduces the load of your body on the stairs and reduces the effectiveness of your StairMaster workout. Ultimately, you want to build your abilities to not hold on at all.

3. Do Two at a Time

Once you’re ready to take your stair-climber workout to the next level, try skipping a step. “By taking big, giant steps, you’ll target the glutes and the upper thighs, where the mass of muscle is,” says Friedman. “The more muscles you get involved, the more calories you burn.” Start slowly and focus on methodically climbing up while keeping your balance, he says.

4. Switch It Up

Going forward targets your glutes and hamstrings, but if you’re looking to work your quads, turn around and complete part of your StairMaster workout backward. “It’s a great move if you’re looking to break up the workout for monotony’s sake or if you want to tone your quads,” says Friedman. Or, try crossover steps, where your body is turned to the right or left as you step up. This move will hit your abductors, stabilizers, and gluteus medius.

5. Add Weights

Feeling confident, steady, and comfortable? Grab a pair of dumbbells before you head over to start your StairMaster workout. As you step up, add a biceps curl, overhead press, or side raises. Multitasking like this works even more muscle groups and elevates your heart rate, says Friedman.

6. Practice Intervals

It’s no secret that we’re fans of interval training. (ICYW, here’s how intervals differ from circuits.) You can translate the benefits of intervals to the stairs too. For the ideal StairMaster workout, shoot for 20 to 30 minutes on the machine. Start with a 10-minute warm-up to activate your heart and your muscles. Then, launch into 10 to 15 minutes of intervals. Start with a 1:1 ratio of high intensity to recovery—say 1 minute on, 1 minute off—followed by a 5- to 10-minute cooldown, suggests Friedman.

7. Monitor Your Heart Rate

After you’ve added the StairMaster to your weekly fitness routine, begin taking note of how your body is reacting. Using a heart rate monitor, measure the time it takes for your heart rate to return to resting levels post-workout, Friedman suggests. As your body becomes more conditioned, that recovery time will shrink. “It’s all about getting your heart rate lower and your recovery time shorter,” he says.