Exercise performance is regulated during repeated sprints to limit the development of peripheral fatigue beyond a critical threshold

Abstract

We hypothesized that exercise performance is adjusted during repeated sprints in order not to surpass a critical threshold of peripheral fatigue. Twelve men randomly performed three experimental sessions on different days, i.e. one single 10 s all-out sprint and two trials of 10 × 10 s all-out sprints with 30 s of passive recovery in between. One trial was performed in the unfatigued state (CTRL) and one following electrically induced quadriceps muscle fatigue (FTNMES). Peripheral fatigue was quantified by comparing pre- with postexercise changes in potentiated quadriceps twitch force (ΔQtw-pot) evoked by supramaximal magnetic stimulation of the femoral nerve. Central fatigue was estimated by comparing pre- with postexercise voluntary activation of quadriceps motor units. The root mean square (RMS) of the vastus lateralis and vastus medialis EMG normalized to maximal M-wave amplitude (RMS.Mmax (-1)) was also calculated during sprints. Compared with CTRL condition, pre-existing quadriceps muscle fatigue in FTNMES (ΔQtw-pot = -29 ± 4%) resulted in a significant (P < 0.05) reduction in power output (-4.0 ± 0.9%) associated with a reduction in RMS.Mmax (-1). However, ΔQtw-pot postsprints decreased by 51% in both conditions, indicating that the level of peripheral fatigue was identical and independent of the degree of pre-existing fatigue. Our findings show that power output and cycling EMG are adjusted during exercise in order to limit the development of peripheral fatigue beyond a constant threshold. We hypothesize that the contribution of peripheral fatigue to exercise limitation involves a reduction in central motor drive in addition to the impairment in muscular function.

The assessment of neuromuscular fatigue during 120 min of simulated soccer exercise

“…The Q tw,pot was reduced from baseline by 15% at HT, and thereafter, no further reduction was observed at FT or ET demonstrating a plateau in the peripheral fatigue response. Such a plateauing of the peripheral fatigue response has previously been demonstrated following selfpaced isokinetic exercise (Froyd et al 2013), intermittent high-intensity cycling (Decorte et al 2012), and repeatedsprint exercise (Goodall et al 2015b;Hureau et al 2014). In line with this study, these previous investigations show a similar biphasic pattern of peripheral fatigue development, whereby most of the decrements in muscle function are manifest early in the exercise bout and are then small thereafter.…”

Modeling Intermittent Cycling Performance in Hypoxia Using the Critical Power Concept

“…As a result, in the intermittent test Work tot 9 CP was not significantly different between NORM and HYPO (Table 3). Our finding that estimates of W ¶, W ¶ BAL, and Work tot 9 CP were not different in NORM and HYPO during equal relative intensity exercise, is consistent with the emerging hypotheses that a) W ¶, and by extension W ¶ BAL , are related to development of peripheral muscle fatigue such as progressive depletion of high-energy phosphates, failure of excitation-contraction coupling, and accumulation of fatigue inducing metabolites (25) and b) the magnitude of peripheral fatigue is a regulated variable that remains approximately the same at the point of task failure under a variety of conditions including moderate HYPO (2), hyperoxia (1), and when neuromuscular electrical stimulation was used to create differing levels of ''prefatigue'' (23).…”

Limitation of fatigue and performance during exercise: the brain–muscle interaction

“…In a recent study (Hureau et al 2014), we used an interventional approach to test this hypothesis. Specifically, we asked whether muscle activation, and therefore power output, are regulated during high-intensity exercise in order to restrain the total degree of peripheral fatigue.…”

“…J Physiol 586, 161-173. Hureau TJ, Olivier N, Millet GY, Meste O & Blain GM (2014). Exercise performance is regulated during repeated sprints to limit the development of peripheral fatigue beyond a critical threshold.…”