Deoxy[Hb+Mb] increases consistently up to peak oxygen consumption in elite cyclists

This study aimed to compare deoxygenation in the vastus lateralis in the skeletal muscle microvasculature of nine world-class/elite (WC/E) vs. thirty-one well-trained/trained (T) cyclists by near infrared spectroscopy (NIRS) during a maximal aerobic power (MAP) test. Interaction analysis showed that 1st degree polynomial trends across % peak oxygen consumption (%VO2peak) differed significantly between WC/E and T cyclists on deoxygenated hemoglobin-myoglobin (Δ[HHb]) and on total hemoglobin-myoglobin (Δ[THb]) from 70 to 100% of VO2peak. These results show that the linear slopes of these trends were different. Near-plateau of Δ[HHb] was observed in T cyclists, whereas a consistent increase up to VO2peak was seen in WC/E cyclists. The Δ[THb] curve declined in T cyclists suggesting that blood volume in the vastus lateralis microcirculation decreases from 70 to 100% of VO2peak whereas it increases slowly but continuously to 95% of VO2peak in WC/E cyclists. The results of this study showed that deoxygenation in the vastus lateralis increases consistently up to VO2peak in WC/E cyclists and seems to be influenced by blood volume in the microcirculation. KCI Citation Count: 0