Lunge, with the front (left) leg placed at a right angle in the knee joint on a small raised surface (e.g. weight disc), the rear (right) leg is placed on the floor on tiptoe only, with the thigh and lower leg also at approximately a 90 degree angle, on the side where the leg is placed on the raised surface, a medicine ball (or another weight such as a dumbbell or kettlebell) is held on the shoulder with the arm bent. From this position, straighten the front leg and simultaneously push the back leg off the floor and bend the knee in a fluid movement to reach a one-legged stance on the raised surface. Then bring the bent knee back again in a raised position and place it on the floor and bend the supporting leg to return to the starting position in a lunge.
Attention:
Always keep the front knee behind the toe and centred over the foot, upper body upright and abdomen tensed.
Lighten:
Lift the knees less, lower the upper body less (greater angle in the knees).
Harden:
Higher base; more weight; additional weight (on the foot); perform a small one-legged jump on the raised base.
Variant:
Hold a weight (dumbbell or kettlebell) in both hands with hanging arms.