Breath-hold time during cold water immersion: Effects of habituation with psychological training

Introduction: The loss of the conscious control of respiration on whole body cold water immersion (CWI) can result in the aspiration of water and drowning. Repeated CWI reduces the respiratory drive evoked by CWI and should prolong breath-hold time on CWI (BHmaxCWI). Psychological skills training (PST) can also increase BHmaxCWI by improving the ability of individuals to consciously suppress the drive to breathe. This study tested the hypothesis that combining PST and repeated CWI would extend BHmaxCWI beyond that seen following only repeated CWI. Methods: There were 20 male subjects who completed two 2.5-min, head-out breath-hold CWI (BH1 and BH2) in water at 12°C. Following BH1, subjects were matched on BHmaxCWI and allocated to a habituation (HAB) group or a habituation plus PST group (H+PST). Between BH1 and BH2 both experimental groups undertook five 2.5-min CWI on separate days, during which they breathed freely. The H+PST also received psychological training to help tolerate cold and suppress the drive to breathe on immersion to extend BHmaxCWI. Results: During BH1, mean BHmaxCWI (± SD) in the HAB group was 22.00 (10.33) s and 22.38 (10.65) s in the H+PST. After the five free-breathing CWI, both groups had a longer BHmaxCWI in BH2. The HAB group improved by 14.13 (20.21) s, an increase of 73%. H+PST improved by 26.86 (24.70) s, a 120% increase. No significant differences were identified between the groups. Conclusion: Habituation significantly increases BHmax on CWI, the addition of PST did not result in statistically significant improvements in BHmaxCWI, but may have practical significance.