Resting pulmonary ventilation in sports scuba divers.

It should be investigated whether the traditional dependency between respiratory and systemic measures is preserved during scuba diving, and whether the diving experience would affect respiration. Additionally, respiration data were analyzed for gender differences (118 sports divers). Respiratory variables were assessed at poolside and during diving in the pool. The respiration pattern at poolside was significantly different from the pattern during diving, where respiration rate (RR) decreased (11.8 +/- 3.8 vs. 7.8 +/- 2.9 min(-1); -34%) and tidal volume increased (1.1 +/- 0.5 vs. 1.6 +/- 0.6 L; +45%). This produced a decrease in respiratory minute volume (RMV) from 12.4 +/- 4.7 to 11.2 +/- 3.8 L/min (-10%). Respiratory Minute Volume and vital capacity correlated at poolside. This physiologic correlation was lost while diving. Instead, RMV and number of dives (= diver's experience) correlated negatively. Because RMV at both poolside and during diving correlates with RR, an increased RMV in diving beginners can be estimated via RR. Thus, close observation of RR could help improve safety during a regular dive, avoiding hazardous hyperventilation. Female divers, irrespective of body height and weight, need less air during diving.