Abstract
This study determined and compared the second muscle oxygenation threshold (MOT2)
in the vastus lateralis (VL) (more active) and biceps brachii (BB) (less active)
muscles in the graded exercise test (GXT). Furthermore, we investigated the
correlation between BB and VL MOT2 with the 3,000-m time trial, as well as the
muscle oxygenation responses during the free-paced strategy of elite endurance
athletes. Nine elite men’s middle- and long-distance runners from the Brazilian
Paralympic Endurance Team performed the GXT in a laboratory setting. MOT2 was
determined by the breakpoint in the tissue saturation index (TSI) curve in both
muscles by wearable near-infrared spectroscopy (NIRS). After 48 h, athletes
performed a 3,000-m running test on an outdoor athletics track while monitoring
the oxygenation in both muscles. MOT2 velocity values in BB (19.3±1.3
km.h−1) and VL (19.4±1.2 km.h−1) did not show a
significant difference between them (p>0.05). We observed a
significant correlation between BB and VL MOT2 with 3,000-m mean velocity
(r=0.88 and 0.86, respectively, p<0.05). Our results
reinforce that the maximal aerobic capacity determined in different muscles
influenced the athletes’ performance in the 3,000-m running. The muscle
oxygenation responses showed that BB and VL worked in an integrated manner
during the GTX and in the 3,000-m running effort.
Keywords
Paralympic athletes - oxygen saturation - running strategy - muscle oxygenation threshold
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