Using RER to estimate RQ is only accurate during rest and mild to moderate aerobic exercise without the accumulation of lactate. The loss of accuracy during more intense anaerobic exercise is among others due to factors including the bicarbonate buffer system. The body tries to compensate for the accumulation of lactate and minimize the acidification of the blood by expelling more CO2 through the respiratory system.
RER estimation of RQ is accurate only during rest and light-to-moderate aerobic activities without lactate accumulation. During more intense anaerobic exercises, the precision diminishes due to factors such as the bicarbonate buffer system. The body compensates for lactate buildup and blood acidification by expelling more CO2 through respiration.