Restoration of blood pH between repeated bouts of high-intensity exercise: effects of various active-recovery protocols
To determine which active-recovery protocol would reduce faster the high blood H+ and lactate concentrations produced by repeated bouts of high-intensity exercise (HIE). On three occasions, 11 moderately trained males performed 4 bouts (1.5 min) at 163% of their respiratory compensation threshold (RCT) interspersed with active-recovery: (1) 4.5 min pedalling at 24% RCT (SHORT); (2) 6 min at 18% RCT (MEDIUM); (3) 9 min at 12% RCT (LONG). The total work completed during recovery was the same in all three trials. Respiratory gases and arterialized-blood samples were obtained during exercise. At the end of exercise, LONG in comparison to SHORT and MEDIUM increased plasma pH (7.32 ± 0.02 vs. ~7.22 ± 0.03; P < 0.05), while reduced lactate concentration (8.5 ± 0.9 vs. ~10.9 ± 0.8 mM; P < 0.05). Ventilatory equivalent for CO2 was higher in LONG than SHORT and MEDIUM (31.4 ± 0.5 vs. ~29.6 ± 0.5; P < 0.05). Low-intensity prolonged recovery between repeated bouts of HIE maximized H+ and lactate removal likely by enhancing CO2 unloading.
KeywordsRespiratory compensation Lactate concentration Neuromuscular power Individual anaerobic threshold Active-recovery Variable intensity exercise
The authors wish to thank the subjects for their invaluable contribution to the study. Juan Del Coso and Nassim Hamouti were supported by a predoctoral fellowship from the Castilla-La Mancha government in Spain.
Conflict of interest statement
The authors of this study declare that they have no financial, professional or other personal interest of any nature in any product, service and/or company that could be construed as influencing the position presented in this manuscript.
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