How long do you have to train overspeed to see the effects?
Depends how healthy you are. After about 10 X’s you will probably be slower and hurt. So i’d say rather quickly!
Sorry
Dan Fichter
I usually see a post like this an skip to something more interesting but we are still seeing olympic athletes being pulled by overspeed cords. This guy anchored a relay at the olympics yet is a 10.48 athlete after having his groin torn up. He came to me for therapy but the cortisone injections did too much and he failed to final at worlds. I never thought I would say this…but I agree with DAN FICHTER.
Ah come on Clemson, it’s not so bad. Sometimes you have to agree to disagree on certain things. Leg springs!!! 
I would never pull you, tow you, over train your hip flexors, or push you off a steep hill to sprint down, I respect you too much.
Dan Fichter