A research article, published online ahead of print (6 September 2013), has revealed evidence that prior-induced inspiratory muscle fatigue (IMF) reduces exercise performance, likely as a result of the increased quadriceps muscle fatigue (QMF).
The study investigated “whether prior-induced IMF would affect subsequent cycling performance via increased quadriceps muscle fatigue (QMF) alone and whether fatigue-induced excess ventilation would contribute to this impairment.”
It concluded “Thus, prior-induced IMF reduces exercise performance likely as a result of the increased QMF and thus greater perception of exertion independent of the excess respiratory drive when cycling with fatigued inspiratory muscles.”
Andrew Jones, Professor of Applied Physiology at Exeter University and endurance sports training, physiology and nutrition expert, has interpreted this to mean “High rates of ventilation over long periods fatigue the diaphragm - more cardiac output directed there rather than to legs.”
Read more research regarding breathing training for cyclists on our Cycling page.