FIGURE 1.

Effect of a ≈6-week endurance training by one individual at the intensity of the 4 mmol^.L⁻¹ lactate threshold (Mader et al. termed it “aerobic-anaerobic transition”) on heart volume measured by X-ray, $\dot{\mathrm{V}}$ O_2max, and the workload at the at 4 mmol^.L⁻¹ lactate threshold. The study also highlights that the exercise protocol (e.g., the duration of each step) affects the lactate curve and that lactate testing should be specific for each sport (e.g., testing rowers on a treadmill has little predictive power). Printed with kind permission from Mader et al. (1976).