Responses towards breath-hold exercise repeated on bicycle ergometer were studied. Interval exercise with continuous breathing, inspiratory breath-holding or expiratory breath-holding was investigated in six young males. In breath-holding exercise PaO₂ decreased and PaCO₂ increased significantly with no difference in heart rate between breath-holding and continuous breathing. Oxygen removal increased with inspiratory breath-holding and mean arterial pressure increased with expiratory breath-holding compared with others. pH became higher with repeating exercise and this response is apparent in breath-holding. Decreases of base excess of extracellular fluid and increases of blood lactic acid concentration were observed, however no significant difference was recognized between those three types of breathing.

DESCENTE SPORTS SCIENCE Vol.5/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE