The effects of breathhold on lactate accumulation, PO2, PCO2 and pH of blood.

This investigation is concerned with the effect of breathholding during exercise on the partial pressure of blood gasses and the energy supply mechanisms of the human body. Subjects (n = 15) included males and females. They were subjected to intermittent exercise periods of 10 s with 10-s resting periods for a duration of 12 min. This protocol was selected to simulate an underwater hockey game during which in-practice intervals of submersion are alternated with intervals on the surface, each of a 10-s duration. Two tests per subject were executed, i.e. one while breathing normally and another where the active period was executed apneically. Statistically significant differences were observed in the PCO2 (breathhold higher than breathing normally; p less than 0.005) and pH (breathhold lower than breathing normally; p less than 0.01) of arterial capillary blood during the exercise period. The lactate concentration of arterial blood did not differ significantly (p greater than 0.05). The PO2 of the breathhold test was slightly lower than that of the control test.