Fig. 1.

Pre- and post-prehabilitation aerobic fitness measurements

a Oxygen uptake (VO₂) at the ventilatory anaerobic threshold (VAT) and b oxygen uptake at peak exercise (VO_2peak). Group data are presented as mean (s.d.). The dashed line represents the cut-off for high risk based on VO₂ at the VAT; patients who score below this cut-off have an increased risk of postoperative complications, which was an inclusion criterion for the present study. *P < 0.001 (paired samples t-test), †P = 0.001 (Wilcoxon signed-rank test).