Fig 8. Fatigue model outputs for a series of progressively higher force plateaus, involving 32 seconds of 20, 40 and 60% separated by 5 s linear ramps from one level to the next.

Endurance time was 101.5 s. (A) Increased excitation in response to fatigue. Force capacity is shown with and without firing rate adaptation and the modeled force remains at the target load until the endurance time. (B) Firing rate of each MU, over the course of the trial. Lines begin when the MU was recruited. Each 20th MU is highlighted and labelled, but all 120 MUs are shown as lighter lines. (C) Force contribution of each MU. (D) Relative force capacity of each MU (normalized to its rested capacity).