Force changes during the fatigue test for motor units in control and trained animal.

<p>The profiles of the fatigue test for fast fatigable (FF; panel A), fast fatigue-resistant (FR; panel B) and slow (S; panel C) motor units. The control (C) group is represented by open circles, the group trained for 2 weeks (2W) is represented by filled triangles, the group trained for 4 weeks (4W) is represented by filled squares, and the group trained for 8 weeks (8W) is represented by filled diamonds. The mean force over time for each group is presented as the relative values reached during the fifth second of the fatigue test, accepted as 1.0 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195704#pone.0195704.s006" target="_blank">S5 File</a>).