It still provides the necessary amount of instability to challenge her balance and coordination and strengthen her core. The 2½ lbs of MDL (multi-dimensional load), which gives the ball its stability also allows her to focus on the proper form for each exercise without worrying about the ball taking off from underneath her. It gave Girlawhirl the confidence to try exercises she may not otherwise have tried on a less stable ball for fear of falling.

The MDL, which is like sand, also provides audible cues during lifting exercises. Girlawhirl was amazed at the intensity of the lifting exercises, and the sounds the MDL made as it shifted. She can do smooth shifts, wave shifts, impact shifts, or movements that make no shift at all. Add to that shoulder and hip stabilization and proper alignment and she got a very tough workout. Her arms will be jiggle free in no time!

Girlawhirl found her BOSU® Ballast® Ball, which comes with a pump and exercise DVD, online at sportsauthority.com.

BOSU® and Ballast® are registered trademarks of BOSU Fitness, LLC.

Tiffany Davidson is a personal trainer based in Weston, CT and the owner of Femme Fatale Fitness. Tiffany advises consulting a physician or health care professional before performing any of the exercises described on these pages or beginning any exercise program. The information herein is not intended to be diagnostic or prescriptive.

Have a question for Tiffany? Click here.