Sat13November1123AM 5

Anaerobic Threshold (AT):

True / False

Is a useful guide in predicting post-operative mortality following major surgery. Correct

Improves with regular training at or a little above the anaerobic threshold Correct

Is the oxygen consumption (VO2) at which an imbalance exists between lactate production and elimination Correct

Improves with patient motivation Incorrect answer selected

Falls by more than 50% between 60 and 80-years of age Incorrect answer selected

Explanation

The anaerobic threshold (AT) falls very slowly with age. Between the ages of 60 and 80-years of age, it falls by approximately 10-20%. AT represents the point in exercise where the products of anaerobic metabolism can no longer be eliminated. As a result, large quantities of bicarbonate buffer are used and CO2 production significantly increases.Training at or little above the anaerobic threshold intensity improves both the aerobic capacity and anaerobic threshold level.. However motivation has no effect. An AT of less than 11ml/kg/min is associated with a high level of postoperative mortality1.

Reference:

(1) Older P. et/al. Preoperative evaluation of cardiac failure and ischeamia in elderly patients by cardiopulmonary exercise testing. Chest 1993; 104:701-4.