Figure 7. Effect of a 12-week aerobic exercise training program in an 82-year-old female patient with coronary artery disease. Panel A, peak oxygen consumption (VO₂); panel B, VE/VO₂, ventilatory equivalent for oxygen; panel C, ventilation to carbon dioxide production relationship (VE-VCO₂) slope (rest-peak); panel D, dead space to tidal volume ratio (VD/VT). Note that after aerobic exercise training the patient showed improvement in both aerobic fitness and ventilatory efficiency (panels A and C, respectively). The patient demonstrated a marked shift to the right of the VAT suggesting improvement in aerobic efficiency (panel B). In addition, the patient demonstrated a sharper reduction in VD/VT showing improvement in gas exchange efficiency (panel D). pre: pre-intervention; post: post-intervention; VAT: ventilatory anaerobic threshold; VD/VT: estimate physiological dead space to tidal volume ratio.