A study by Russian scientists, to determine which plyometric exercises correlate to sprinting, revealed:
That only horizontal single leg hops for distance, had a significant correlation to sprint times. The other plyometric exercises did not correlate significantly to sprint times.
Also in sprinting, the power of the forward swing leg is bigger factor on speed of support leg. Not just the strength of the support leg muscles and tendons.
And so horizontal hops train most of the elements. The ground contact force is higher in horizontal hops than sprinting. Therefor, why would you need jumping for hieght? (Box jumps, depth jumps, drop jumps.)
Also, the psoas above swing leg is doing its job of whipping swing thigh forwards, during the horizontal hops. It’s surely a better drill/exercise, for running than depth jumps.
Forward med ball swing hops. On 1 leg. Great for strength.
“Weight swing switches”. Great indoor exercise for sprinting fitness. Partial backwards med ball throw action without letting go of ball, imediately switching to forwards and down throwing action, to return to start position. That is, ball held in two hands between knees/shins. Quater squat position. But doing it very quickly for 25 to 45 reps continously. With no pauses between movements. Only count the upward movement as a rep.
This trains cardio system and even allows you to move in to anterior pelvic tilt at top position. A plyometric effect, because your feet come off the floor a few inches, as your feet slide backwards, when med ball travels backwards overhead. Feet land behind your center of mass. So you have too imediately return to down swing. As you swing ball forwards and down, feet pick up and slide forwards. knees bend and hips drop, and you land in to quater squat. You imediately explode back up in to reverse med ball swing action.
The entire posterior chain and much of the anterior chain, is getting a plyometric effect from the above exercise.
When not enough time to get in a track / outdoor session, the above exercise is excallent.