Q8 - Oxygen Uptake and Lactate During and After Exercise
Oxygen uptake and lactate concentration in the blood were measured in a 70 kg male person before, during and after he had exercised (worked) for 4 minutes. The intensity of the exercise (work) corresponded to the consumption of 5 L oxygen/min.
Changes in oxygen uptake (purple, left Y-axis, L/min) and lactate concentration (black, right Y-axis, mM lactate in blood) before, during and after an exercise or work period of 4 min.
Figure 1.
Using the information and data, determine which of the statements are true or which are false.
A. The person cannot work for 4 min at intensities equal to 5 L O₂-uptake/min, as his maximum aerobic work capacity is 4.2 L/min
B. The person has an aerobic capacity of 60 ml O₂/(kg·min)
C. When blood lactate exceeds 11 mM, excretion begins through the kidneys, which is why its concentration declines
D. Excess O₂-uptake after the end of work is partly due to metabolism of lactate and not to gluconeogenesis
Question reproduced from IBO 2015, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)