Stand on one leg (left) on an elevated surface (e.g. flat bench, vaulting box element incl. top, long bench), with the supporting leg on the elevation strongly bent (one-legged knee bend with less than 90 degrees in the knee joint) and the other leg also bent with the front foot slightly offset to the side on the floor, resting the arms on the hips. From this position, push the (lower) foot off the floor and stretch it, while at the same time stretching the raised foot so that the body is stretched in a one-legged stance (left). In a fluid movement, bend the raised leg (left) back to the starting position and move the free leg to the other side of the body (stand on the front foot again with the leg bent). In a continuous alternation, the free leg is spread slightly to the side and then crossed over/backwards behind the supporting leg to the other side.
Attention:
Always keep the front knee behind the tip of the foot and centred over the foot. Lower your body in the centre (follow the back knee like a plumb line, keep your upper body upright, tense your stomach).
Lighten:
Lower your upper body less (greater angle in the knees); no or less high support.
Harden:
Additional weight (on the shoulders).
Variation:
Lift the hands from the hips while stretching the body and extend them backwards along the body; when bending the supporting leg again, bring the hands back to the hips.