Triceps dips are hard enough when you do them off a bench or chair. Using a stability ball instead makes them even more challenging for your core muscles because they have to work harder to keep your balance, says Jennifer Willis, certified personal trainer at So-Be-Fit, a personal training and wellness studio in south Broad Ripple. Of course, the exercise is a great one to tone those flabby underarm areas.

Willis — a former civil engineer and an avid runner who has done several half and full marathons — works individually with clients at the studio, in their homes and in corporate settings. She also teaches group fitness classes, including sculpting and Pilates fusion, at the studio, which moved earlier this year to 1134 E. 54th St., Studio B, www.sobefitindy.com, (317) 697-1939. So-Be-Fit also offers yoga, boxing boot camp, spinning, Zumba and biggest loser challenge classes.

Willis demonstrates how to do this exercise.

Step 1: Place a stability ball against a wall and sit on the edge of the ball, with your knees bent and feet about a shoulder-width apart. Place your hands behind you on the ball, and extend them to lift your body off the ball.

Step 2: Inhale and flex elbows, lowering your body until the upper arms are parallel with the floor.

Step 3: Exhale and extend your arms until they are straight, lifting up your body and keeping your knees bent. Don’t rest on the ball, but repeat the motion.

Repetitions: Do 10 to 15 repetitions.

Tips: To make this exercise even more challenging, bring the ball away from the wall.

— Barb Berggoetz

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