Exercise Heart Rate as a Predictor of Oxygen Consumption During Decompression from Saturation Diving

摘要

The correlation between heart rate and oxygen consumption has been questioned during submerged exercise or exercise under pressure. We studied the relationships of heart rate to oxygen consumption (VO2) and of VO2 to ergometer setting in eight divers during decompression from a saturation dive in a helium- oxygen atmosphere. Measurements were made at 300,190, 66, and 33 feet of seawater (1019, 682, 303, 202 kPa (a)). VO2 during submerged exercise (maximum 75 W) was calculated from the MK 16 underwater breathing apparatus (UBA) bottle pressure drop, and during dry exercise (up to 75% of maximum V02) by expired gas collection. VO2 increased linearly with ergometer work with the same slope submerged or dry, but the no-load intercept was higher submerged than dry. The work of moving the water and of breathing on the UBA corresponded to 54 W i 15 W. Heart rate increased linearly with VO2. The slope was independent of depth or immersion, and the intercept was independent of depth. The median error in estimating VO2 from heart rate was 12% on the surface, 23% submerged, and 31% in the dry chamber. Heart rate was not a good predictor of VO2 during dry or submerged exercise in the hyperbaric chamber.