Speeding of…kinetics during moderate-intensity exercise subsequent to heavy-intensity exercise is associated with improved local O2 distribution.

The relationship between the adjustment of muscle deoxygenation (Δ[HHb]) and phase II Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. during moderate-intensity exercise was examined before (Mod 1) and after (Mod 2) a bout of heavy-intensity "priming" exercise. Moderate intensity Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. and Δ[HHb] kinetics were determined in 18 young males (26 ± 3 yr). Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. was measured breath-by-breath. Changes in Δ[HHb] of the vastus lateralis muscle were measured by near-infrared spectroscopy. Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. and Δ[HHb] response profiles were fit using a monoexponential model, and scaled to a relative % of the response (0-100%). The Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. ratio for each individual (reflecting the local matching of O₂ delivery to O₂ utilization) was calculated as the average Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. response from 20 s to 120 s during the exercise on-transient. Phase II Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. was reduced in Mod 2 compared with Mod 1 (P < 0.05). The effective τΔ[HHb] remained the same in Mod 1 and Mod 2 (P > 0.05). During Mod 1, there was an "overshoot" in the Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. ratio (1.08; P < 0.05) that was not present during Mod 2 (1.01; P > 0.05). There was a positive correlation between the reduction in the Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. ratio and the smaller Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. from Mod 1 to Mod 2 (r = 0.78; P < 0.05). This study showed that a smaller Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. during a moderate bout of exercise subsequent to a heavy-intensity priming exercise was associated with improved microvascular O₂ delivery during the on-transient of exercise, as suggested by a smaller Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. ratio. [ABSTRACT FROM AUTHOR]