I’ve been wondering how much upperbody strength can contribute to sprinting, so I’m going to ask a question here. Does anyone have any real evidence of the force produced by sprinters in the arms/deltoids, pecs, etc? Because I am really debating whether or not I should waste my time working out my rear deltoids.
If we think about it like this it makes sense. If the biceps + deltoids + pecs (arm flexion) along with the synergistic arm extension (rear delts, the lats, triceps, traps, other back muscles) contributes 15% to overall ground reaction force (GRF) in athlete A, and through training our legs only, we increase our ground reaction force by 100% let’s say, then the upper body’s role decreases to 7.5%. If we then decide to restore the original ratio without decreasing leg strength, we end up with increased GRF. If that is how it works, then isolating the upperbody to improve strength should make you faster.