Fig. 2. Sample single-dive MR (rate of oxygen uptake) calculation using a 5 min dive trial with M1. Oxygen consumption was sampled every 10 s. Horizontal line A represents the baseline MR calculated from the area under the metabolic curve divided by the duration; A=5.12 ml O2 min–1 kg–1. Horizontal line B represents the post-recovery MR calculated from the area under the metabolic curve divided by the duration; B=5.09 ml O2 min–1 kg–1. The recovery interval contains all the post-dive O2 debt, including 3 min of post-recovery MR, to ensure that all the O2 debt has been included; recovery=46.18 ml O2 kg–1 and covers a 4.67 min period. The average baseline rate is (A+B)/2=5.11 ml O2 min–1 kg–1. The portion of the recovery period MR which is accounted for by the baseline MR is 4.67 minx5.11 ml O2 min–1 kg–1=23.86 ml O2 kg–1. Therefore, the O2 debt from the dive is 46.18 ml O2 kg–1–23.86 ml O2 kg–1= 22.32 ml O2 kg–1, and the dive MR is 22.32 ml O2 kg–1/5.0 min=4.46 ml O2 kg–1min–1.
