Overspeed Trainer for Speed This is one of the best devices for overspeed training and resistance training. A pulley system provides a smooth buildup of speed. Athletes can release themselves quickly if they are running too fast. It can be used for any distance up to 100 meters. When the lead pacer runs at 50% speed, it enables the sprinter to move at a rate greater than 100% of their usual top speed. If done correctly, both the pacer and the sprinter will reach the desired training distance at the same time, causing the rope to release. For resistance training, the sprinter leads the way with the pacer following behind, holding back the sprinter. Comes complete with instructions. Cord runs from front of runner #2 through pulley attached to the back of runner #1 and ties off to a secure object (#3). The pulley allows runner #2 to run twice as fast as runner #1 covering any distance up to 100 yards. The amount of overspeed is controlled by how fast runner #1 moves.