The 'Jumping Jack' is a great warm-up exercise. You stand upright with closed legs and put your arms stretched and downward by the side of the body. Now move down slowly, make a little jump and stretch away your legs and arms simultaneously. Then you move down and make another little jump and come to the starting position with closed legs and arms beside your body. If you repeat this exercise 25-30 times your body should be warmed up and ready for the real workout.