Accelerated point of muscle deoxygenation during the 20‐m shuttle run test

Abstract

This study examined whether the point of accelerated deoxygenation of active muscle occurs during the 20-m shuttle run test (20mSRT) and, if so, whether it is associated with exercise performance in the test. Twenty-nine male subjects performed the 20mSRT, and concentration changes in oxyhaemoglobin (ΔOxy-Hb) and deoxyhaemoglobin (ΔDeoxy-Hb) in the m. vastus lateralis were measured using a portable near-infrared spectroscopy device. The difference between the relative concentration changes in ΔOxy-Hb and ΔDeoxy-Hb (Δ[Oxy-Hb - Deoxy-Hb]) was regarded as the muscle oxygenation index. Group-averaged Δ[Oxy-Hb - Deoxy-Hb] showed progressive decrease during the test. However, among the individuals, we found an accelerated point of decrease in Δ[Oxy-Hb - Deoxy-Hb] in 20 subjects, which revealed that the laps at the accelerated point correlated with the total laps (r = 0·78). These results demonstrate that the accelerated deoxygenation of active muscle occurs during the 20mSRT, but not in all cases. Our findings also indicate that if the accelerated point of muscle deoxygenation occurs, the timing of its appearance is related to 20mSRT performance.

Muscle deoxygenation and oxygen uptake plateau occurrence in children with obesity

“…At the level of the vastus lateralis, BP deoxy[heme] appeared positively correlated with VO 2max (21) and the lactic threshold (22) in adults, but this was not observed in children (23). In boys, the timing of BP deoxy[heme] correlated with the number of stops completed during the 20m shuttle run test (24) suggesting that running aerobic performance is partly determined by the balance between O 2 delivery and utilization at the thigh muscles level. Likewise, it could be hypothesized that the balance between O 2 delivery and utilization at the calf muscles' level is a major determinant of aerobic performance during a walking test.…”