off the ground moves behind the person as they squat, but alternatively the person may position it ahead of themselves. Bilateral split squats which significantly increase the work performed by the front leg are sometimes erroneously referred to as single leg squats due to this emphasis. Single leg squats can be used to strengthen a person's stabiliser muscles more so than two legged squats and improve their ability to balance. They can also be used to remove muscle imbalances in the body by ensuring that, when performed alternatively, the right and left leg do the same amount of work. In comparison to two footed squats, the barbell weight only needs to be half of what it would be for the legs to perform the same amount of work i.e. lifting 40 kg using only the left leg, means the left leg is lifting the equivalent of what it does in a two footed squat with 80 kg. This means that the single leg squat can be used in rehabilitation programmes where there is a need to avoid heavier loading of the back. Loaded squat jump – the barbell is positioned similarly to a back squat. The exerciser squats down, before moving upwards into a jump, and then landing in approximately the same position. The loaded squat jump is a form of loaded plyometric exercise used to increase explosive power. Variations of this exercise may involve the use of a trap bar or dumbbells. Variable resistance squat – In keeping with variable resistance training in general, a variable resistance squat involves altering the resistance during the movement in order that it better matches, in percentage terms, the respective 1RM for each strength phase the person is moving through i.e. more resistance in the higher stronger phase and less in the weaker lower phase e.g. 60 kg in the lower phase and 90 kg in the higher phase. Such an alteration of resistance can be achieved by the use of heavy chains which are attached to either end of the barbell. The chains are gradually lifted from the floor as the barbell is raised and vice versa when it is lowered. Thick elastic bands which are more stretched in the higher phase and less stretched in the lower phase can also be used. Combining heavier partial reps with lighter full reps can also help to train the stronger and weaker phases of