Understanding F₀ and v₀

There are multiple variables calculated from force/velocity profiling with the two main outputs being $F_0$ and $v_0$. These two, and other variables, are calculated from velocity development during a linear sprint where weight and height of the runner, air resistance and pulling force (if applicable) are included.

• F₀ (Force Intercept): $F_0$ represents the theoretical maximal horizontal force the athlete could produce when starting from rest (i.e., at zero velocity). This value reflects the athlete’s force-producing capability.

• v₀ (Velocity Intercept): $v_0$ is the theoretical maximum sprinting speed that the athlete could achieve if the force output dropped to zero. Although no athlete actually reaches $v_0$, it serves as a benchmark for their speed potential.

Together, these parameters help coaches and sport scientists evaluate whether an athlete is more force- or velocity-oriented. Example, a sprinter with a high $F_0$ but relatively lower $v_0$ might benefit from training that enhances speed mechanics, while an athlete with a high $v_0$ might focus on developing more force production during the start phase.

Relationship between F₀, v₀ and power

The relationship between $F_0$ and $v_0$ is linear with the peak power ($P_{max}$) output at 50% of the $v_0$.

Figure 1: Combined F/v plot showing both force and power as a function of speed. Force and power are both adjusted for body weight.