Force Velocity Relationship

[Ethang79]

Hey guys, I listened to the programming tweaks podcast and you guys talked about how the earlier reps in a set may be more important than the last couple reps in a set because the bar speed and velocity is higher during the earlier reps, which means there is more force being produced, and the reps with higher force production are the ones we should care about. However, I recently started reading Strength is Specific by Chris Beardsley and he talked about how less force is produced at higher velocities because the myosin actin cross ridges detach at a quicker rate. Wouldn't this mean that there is actually less force being produced during the earlier reps with higher bar speeds, and more force being produced during the last couple reps in a set where bar speed and velocity declines? I was hoping you guys could clear this up for me, I think I may be misunderstanding what you guys said in the podcast.

[Jordan Feigenbaum]

Yea this is an area of contention between those in the "effective reps" camp like Beardsley and those who think that substantial decrease in velocity may actually impair strength adaptations (if it makes up the bulk of training) due to excess fatigue incurred with these efforts.

I think you understand it just fine based on this post, but we probably tend to agree more with second camp.

[4l3x]

Hey guys, I listened to the programming tweaks podcast and you guys talked about how the earlier reps in a set may be more important than the last couple reps in a set because the bar speed and velocity is higher during the earlier reps, which means there is more force being produced, and the reps with higher force production are the ones we should care about. However, I recently started reading Strength is Specific by Chris Beardsley and he talked about how less force is produced at higher velocities because the myosin actin cross ridges detach at a quicker rate. Wouldn't this mean that there is actually less force being produced during the earlier reps with higher bar speeds, and more force being produced during the last couple reps in a set where bar speed and velocity declines? I was hoping you guys could clear this up for me, I think I may be misunderstanding what you guys said in the podcast.

You can produce more force against more resistance. If you are moving the same weight slower you are producing less force (Newton's second law). I suppose there's some nuance here with antagonist activation.

If you slow down due to fatigue it's possible some muscle fibers may start producing more force, but the whole muscle force is lower (this is really speculative and how that might inform training is really getting into it).