An incremental-speed running test until fatigue on a treadmill (LE400, Panlab, Harvard Apparatus, Cornella, Spain) was performed to assess the peak speed (Speak). All these incremental running tests were performed at least 24 h after the last familiarization session. During this test, the mice began running at 6 m min–1 and the speed was increased by 3 m min–1 every 3 min at 5° slope until fatigue (Ferreira et al., 2007). Fatigue was defined as the moment at which the animals were unable to maintain their pace with the treadmill speed for at least 10 s, even when exposed to slight electrical stimulation.