Breath holding with water immersion in synchronized swimmers and untrained women.

Breath holding (BH) and water immersion induce several physiological responses. Individuals, who are BH trained tend to have an advantage versus untrained subjects. This study compared physiological responses to BH at rest between synchronized swimmers (SS) and controls (C). Each participant performed five resting BH periods in water. Breath holding periods were significantly longer for SS (109.8 +/- 39.3 vs. 78.3 +/- 25.0s), despite a similar end tidal partial pressure of carbon dioxide and oxygen following BH. Recovery times after BH were similar for oxygen consumption, ventilation, and blood oxygen saturation. Synchronized swimmers (SS) experienced bradycardia at 45s of max BH, whereas C did not (60 +/- 9 vs. 65 +/- 14 b x min(-1)). A significant oxygen conservation effect occurred for SS in only one BH trial. These results suggest that SS exhibited an enhanced ability to breath hold with similar respiratory responses but a lower heart rate (HR) during recovery, suggesting a better adaptation to BH.