Reaction Ball Challenge Works entire body and improves balance.
You'll need: A partner and a reaction ball (a small, knobby ball that's designed to bounce in different directions at random) or other small ball, such as one used for racquetball.
A. Stand facing your partner, several feet apart (for more of a challenge, stand six to eight feet apart).
B. Toss a reaction ball or other small ball (such as one used for racquetball) so it lands two to three feet in front of your partner.
C. Your partner should shuffle and try to catch the ball on the first bounce (if you're using a reaction ball, this will be especially challenging, since it will bounce in different directions at random).
D. Your partner will then throw the ball back to you the same way.
E. Continue for 25 seconds, break for a minute, and repeat for a total of three times.