The impact of pedal rate on muscle oxygenation, muscle activation and whole-body VO2 during ramp exercise in healthy subjects

Abstract

The present study showed that muscle activation and oxygenation at high intensities during incremental exercise are related to pulmonary VO2 rather than external WR, with a close interrelationship between that muscle activation, oxygenation and pulmonary VO2.

Effect of pedaling cadence on muscle oxygenation during high-intensity cycling until exhaustion: a comparison between untrained subjects and triathletes

“…On the other hand, previous studies that were interested in the effect of pedaling cadence on muscle oxygenation, by using near-infrared spectroscopy technology (NIRS), reported a similar level of O 2 extraction independently of the cadence during incremental exercise (Ferreira et al 2006) and during moderate exercise (Kounalakis and Geladas 2012;Zorgati et al 2013). Nevertheless, Boone et al (2014) observed a greater muscle O 2 extraction at the highest pedaling cadence during incremental ramp exercise.…”

“…It should be considered that ∆deoxy[Hb + Mb] reflects the balance between V O 2M and Q O 2M (i.e., V O 2M /QO 2M ratio) and thus microvascular O 2 extraction [i.e., proportional to C(a−v)O 2 ] (Boone et al 2014;DeLorey et al 2003;Ferreira et al 2006;Grassi et al 2003;Koga et al 2007) and ∆total[Hb + Mb] reflects the increase in microcirculation hematocrit (Hct) during (Boone et al 2014;Davis and Barstow 2013;Poole et al 2013).…”

“…∆deoxy[Hb + Mb] represents variations in the V O 2M /QO 2M ratio in the capillaries, reflecting the change in O 2 extraction [i.e., proportional to C(a−v)O 2 ] in the muscle (DeLorey et al 2003;Grassi et al 2003). Total[Hb + Mb] is a measurement of (oxy[Hb + Mb] + deoxy[Hb + Mb]) and its changes are suggested to represent variations in hematocrit of the microcirculation during exercise (Boone et al 2014;Davis and Barstow 2013).…”

“…Although several studies have been interested in the effect of pedaling cadence on performance, to our knowledge, no study focused the attention on muscle oxygenation during heavy exercise until exhaustion at two different cadences. Indeed, the few studies that have examined the effect of the pedaling cadence on muscle oxygenation have used incremental exercise (Boone et al 2014;Ferreira et al 2006) or moderate constant load exercise (Kounalakis and Geladas 2012;Zorgati et al 2013). However, the kinetics of the O 2 extraction during incremental exercise is complex (Boone et al 2009) and the effect of pedaling cadence on the muscle oxygenation responses during constant load exercise could be different.…”

“…When studying the effect of the pedaling cadence, these previous works were performed in subjects who were not endurance trained (Boone et al 2014;Ferreira et al 2006;Kounalakis and Geladas 2012;Zorgati et al 2013). In muscle, endurance training is associated with increased activity of key enzymes of the mitochondrial electron transport chain, an increase in mitochondrial protein concentration and an increase in capillary supply.…”