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TESTING & ASSESSMENT

The Force-Velocity Profile: What It Is and Whether You Need It

The F-V profile tells you whether strength or speed is your bottleneck — and when you are not ready for it yet.

August 5, 20267 min read

The force-velocity profile fits the muscle's force-velocity relationship to your jumps at different loads. It turns 'am I weak or slow?' from a guess into a number.

What it measures

Four outputs come from the profile: F₀ (theoretical max force at zero velocity), V₀ (theoretical max velocity at zero load), Sfv (the F-V slope, or force-velocity balance) and Pmax (peak power = F₀ × V₀ / 4).

What the diagnosis means

If your Sfv deviates more than 40% from optimal, targeted training can improve the balance by 15–30%. A force deficit points to strength training; a velocity deficit points to speed work.

How often to test

Once per training cycle (8–12 weeks) is right — the variables change slowly, and weekly testing only adds noise. And if your squat is below 1.5x bodyweight, build the strength base before testing at all.

Key takeaways

  • F-V profile separates force deficits from velocity deficits.
  • Test once per 8–12 week cycle, not weekly.
  • No strength base, no F-V test — build to a 1.5x squat first.

References

  • Jiménez-Reyes et al. (2017) Scand J Med Sci Sports
  • Samozino et al. (2012) Med Sci Sports Exerc
  • Morin & Samozino (2016) Sports Med

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