Strengthen your abs and your bond at the same time with this toner: All you need is a medicine ball (you can use any similar-sized ball if you don’t have one). Kneel on the floor back-to-back, and slowly twist to one side to hand the ball off to your partner (who should be turning toward you). Then twist to the other side as they turn to hand the ball back to you. Continue passing the ball in that direction for 60-90 seconds, and then repeat the exercise in reverse.
KNEELING PARTNER TWIST