I agree that it is two-fold!!! Leg strength AND mental/physical Discipline!!! No matter 'whos' stances 'or' postures of any height , you hold,....it's a 'feeling' as explained by C. Jung that the monks had to endure! But,..with excellent results,...again', no matter 'whos' stances/postures/static programs you train under,(as long as the mechanics of healthy posture and alignment are correct). Li Ma-Keh