Stability ball crunches can become pretty easy for some people, but is there a way to actually make these more intense? I’m a certified personal trainer.

The easiest way to do stability ball crunches is with arms extended out in front of yourself.

To add intensity, press arms in an “X” to your chest. One step higher in difficulty is to extend arms behind your head, straight, and keep them there as you do the crunches.

However, don’t cheat by swinging your arms forward and letting them get ahead of your body as your torso raises with the crunch.

Elbows must remain aligned with ears at all times. This adds intensity that you will notice immediately to stability ball crunches.

To make this arms-out-behind you more intense, hold a 5 pound weight plate or 5 pound dumbbell.

Again, do not allow your arms to lead with the crunch. Elbows stay right next to ears at all times. And arms remain straight; do not bend them.

You’ll be tempted to jerk the arms forward for some momentum to get you up; do not do this. Let your abs do all the work.

The obvious way to add intensity at this point, is to hold onto a heavier weight.

But are there other ways, besides what I have just described, to bring more intensity to stability ball crunches? Yes, there certainly are.

One way is to hold the crunch position for a few seconds at its toughest point. Don’t lie back down on the ball right away.

Hold yourself up in the crunch position, and do not hunch or round your back. Keep a little arch in the lower back.

Another way to make stability ball crunches more difficult is to hold a weight plate against your chest.

If you let the weight stray outward, it becomes easier to move with the weight. So keep it firmly pressed to your chest throughout the entire routine.

Throughout any of these various modifications of crunches, make sure that the stability ball remains fixed on the floor, rather than rolling about.

This can be accomplished by keeping your feet firmly planted in the same position throughout all the repetitions, and by avoiding jerking your body upward.

Lift your shoulders and back off the ball in a controlled way, focusing on making your abdominal muscles do all the work. Jerking motions will take work away from the abs.

The last way you can ensure some added intensity is to make sure that the stability ball isn’t big. They come in different sizes, and the bigger this implement is, the more initially inclined your body will be at the beginning of the crunch motions. Try the routine with a ball that’s smaller than what you usually use.

Lorra Garrick is a former personal trainer certified through the American Council on Exercise. At Bally Total Fitness she trained women and men of all ages for fat loss, muscle building, fitness and improved health.