Voluntary hypocapnic hyperventilation lasting 5 min and 20 min similarly reduce aerobic metabolism without affecting power outputs during Wingate anaerobic test

Abstract

Twenty minutes of voluntary hypocapnic hyperventilation prior to exercise reduces the aerobic metabolic rate with a compensatory increase in the anaerobic metabolic rate without affecting exercise performance during the Wingate anaerobic test (WAnT). Thus, pre-exercise hypocapnic hyperventilation may be a useful means of stressing the anaerobic energy system during training, ultimately improving anaerobic exercise performance. However, it remains unclear whether a shorter (e.g., 5 min) pre-exercise hypocapnic hyperventilation is sufficient to reduce the aerobic metabolic rate during high-intensity exercise. We therefore compared the effects of 5-min and 20-min pre-exercise hypocapnic hyperventilation on aerobic metabolism during the 30-s WAnT. Ten healthy young males and one female performed the WAnT following 20 min of spontaneous breathing (control trial) or 5 or 20 min of voluntary hypocapnic hyperventilation. Both the 5-min and 20-min hyperventilation reduced end-tidal CO₂ partial pressure (an index of arterial CO₂ partial pressure) to ∼23 mmHg, whereas it remained unchanged during the spontaneous breathing. The peak, mean and minimum power outputs during the WAnT did not differ among the three trials. Oxygen uptake during the WAnT was lower in both the 5-min (1493 ± 257 mL min⁻¹) and 20-min (1397 ± 447 mL min⁻¹) hyperventilation trials than during the control trial (1847 ± 286 mL min⁻¹), and was similar in the two hyperventilation trials. These results suggest that 5 min of pre-exercise hypocapnic hyperventilation reduces aerobic metabolism during the 30-s WAnT to a level similar to that seen with the 20-min hyperventilation. Moreover, exercise performance was unaffected, which implies anaerobic metabolism was enhanced.

Keywords:

• Hyperpnea
• respiratory alkalosis
• aerobic metabolic rate
• anaerobic metabolic rate
• sprinting

Acknowledgements

We sincerely thank Yuki Kawamuro for recruiting the volunteer participants and supporting the experiment. We thank the volunteer participants. We also greatly appreciate the help of Dr. William Goldman (English editing and critical comments). K.D. and T.N. conceived and designed experiments; K.D. and T.F. performed experiments; K.D. analyzed data; K.D., N.F., M.I., T.F. and T.N. interpreted results of experiments; K.D. prepared figures; K.D. drafted manuscript; K.D., N.F., M.I., T.F. and T.N. edited and revised manuscript; All authors approved the final version of manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the grants from the Ministry of Education Culture Sports Science and Technology [JSPS KAKENHI; grant number 18J20086]. K. Dobashi is the recipient of a research fellowship for young scientists from the JSPS.