TYR's Hydrofoil Kickboard puts a swimmer's body in a more effective position while kicking, so if you're looking for a way to make your training feel more efficient or to just mix up your workouts, the Hydrofoil fits the bill on both counts. With a convex bottom "hull," the board allows the upper body to roll slightly from side-to-side in time with the lower body as it would while swimming freestyle, which feels far more realistic than hanging onto a static board. TYR also shaped the board to allow hands and forearms to be able to rest naturally on top of it in a similar position to where they would be after pulling through a stroke.