Powercore Yoga BlockPowercore Yoga Block A yoga block is a tool used as a prop in yoga. They are designed to help support and stabilize you along with alignment, deepening a stretch, or adding height off the ground. Provide extra support and stability in seated and standing poses when first learning how to balance. Help more advanced yogis achieve deeper stretches by extending reach. Be used creatively in sun salutations and vinyasa flows to add variety to a practice.