Chapter 78 - Exercise ([formula omitted] and RQ)

Abstract

VO2(max) is a reliable indicator of physical conditioning. O2 utilization by working muscles is a physiologic variable that can limit the exercise performance of normal animals. The excess O2 consumed during recovery from exercise is in payment of the “oxygen debt” incurred during exercise. Lactate tolerance can be improved with physical conditioning. The RQ is the ratio of CO2 produced to O2 utilized, and it is a useful indicator of the types of fuels being utilized during exercise. In normal fed animals, the RQ of the brain during exercise is usually close to unity. 31P NMR has been used to measure concentrations of phosphorylated metabolic intermediates in tissues during exercise.