The self braking system keeps the sleigh from running into the calf's heels.

 

The training sleigh needs to be lightweight, have high clearance for unexpected off-road adventures, and it needs to be self-braking to prevent it from sliding into the calf’s heels. This particular model meets all those requirements and comes with baked on powder enamel finish.

Actually this is the frame of a discarded treadmill turned upside down. It works great!