Our 45' Speed Cords are deisgned for longer distance sprint drills. This cord is not for beginners or untrained athletes. These cords will stretch 45 yds and produce significant tension when fully stretched. This cord is ideal for training track athletes, 40 yd dash, or any other discipline requiring sprints over 40 yds. Each cord will come in light, meduim, and heavy resistance levels, and will have a protective sheathing. This cord goes great with our "H" Harness or 360 Belts, as well as our Stride Ladder.