The oxygen cost of an escape from an underground coal mine

Six 27- to 63-year-old coal miners performed an "escape" maneuver from an underground mine along a passageway that required walking and running erect or stooped, duck walking and crawling. The miners traveled at different speeds, for each mode of locomotion. The minute pulmonary ventilation (VE), O2 uptake (VO2) and heart rate (HR), recorded continuously on a magnetic tape via lightweight meters carried on the miners' waists, indicated similar average and peak values for all modes of locomotion. The mean VE, VO2 (L X min1, STPD) and HR (b X min1) were, respectively, 49, 1.63 and 143 for the average values, and 52, 1.92 and 161 for the peak values. Compared to the aerobic capacity obtained during graded treadmill test to exhaustion, the average effort of the "escape" was performed at 64% and the peak effort at 70% of the miners aerobic capacity for an "escape" time of 58 minutes.