If you can barely do one, you're probably doing it right.

You might be able to bang out a few (or a dozen!) solid standard push-ups-but as soon as you scooch your hands in a few inches, can you keep it up? Honestly, probably not. That's because close- or narrow-grip push-ups are murder for your triceps-the small yet important muscle group on the back of your upper arms.

But, like pull-ups and pistol squats, the hard exercises are totally worth your time. Here's why.

Triceps Push-Ups Benefits and Variations

"These are definitely more challenging because the emphasis is placed on your triceps," says Rachel Mariotti, the NYC-based trainer demo-ing the move in this video. Indeed, compared to a standard push-up or a wide-grip push-up, narrow-grip push-ups require more activation in the triceps, chest muscles, and infraspinatus (one of the muscles in your rotator cuff), according to a study published in the Journal of Physical Therapy Science.

"Narrow-grip push-ups are a great way to load the triceps with bodyweight while also activating chest, shoulders, and core," says Mariotti. One of the biggest form mistakes she sees? Sagging of the back and hips due to weak core activation. Remember: Push-ups are just moving planks. If you're struggling to execute a triceps push-up, make sure you don't let your core go loose to compensate.

Because these things are hard, you may need to work on some progressions first. Dropping your knees to the ground is always a good idea to focus on form-just make sure you're still engaging your core and not hinging at the hips. You can also try performing them with your hands on an elevated surface like a bench, box, or step. (You can also strengthen your triceps with other exercises to prep for triceps push-ups.)

Ready to up the ante? Try a triangle or diamond push-up, the even-more-advanced version of a triceps push-up. In fact, in a study on the most effective triceps exercises, the American Council on Exercise found that the triangle push-up elicited more activity in all three triceps muscles than triceps dips, triceps kickbacks, overhead triceps extensions, bar push-downs, rope push-downs, close-grip bench press, or lying barbell triceps extensions.

How to Do a Triceps Push-Up

A. Start in a high plank position with palms just narrower than shoulder-width apart. Engage quads and core as if holding a plank.

B. Inhale and bend elbows straight back to lower entire body simultaneously toward the floor, triceps tight next to ribs. Pause when chest is just below elbow height.

C. Exhale and press into palms to push body away from the floor to return to starting position, moving hips and shoulders at the same time.

Do 8 to 15 reps. Try 3 sets.

Triceps Push-Up Form Tips

  • Don't allow hips or low back to sag toward the floor, or any hinging to happen at the hips or lower back.
  • Keep neck neutral and gaze slightly forward on the ground; don't tuck chin or lift head.
  • Keep elbows tucked tight in to sides.
  • Don't allow upper back to "cave in" or chest to push forward. When in high plank, isometrically push chest away from the floor and then push up from that position.