It is will known that high RQ (>1.0) is frequently observed during heavy exercise with an increase of O₂ uptake. The accumulation of lactate with lowering of bicarbonate pool in body may be caused by the higher increase of CO₂ output than O₂ uptake. As if the metabolic RQ is assumed within 1.0, the amount of excess “non-metabolic” CO₂ will be measured over 1.0 from that of CO₂ product.
　This study was designed to clarify the relation between excess CO₂ and blood lactate during submaximal work. We use three different loads (60, 80, and 95% of VO₂max), after obtaining of VO₂max with leg exercise on a bicycle ergometer. All subjects were studied on the assigned work load for 5 min. Blood sample was taken 4 times in each trial, and blood lactate was measured by Barker-Summarson method.
　There was a linear correlation between excess CO₂ and ⊿ (delta) blood lactate in all subjects. The correlation coefficient was r=0.936. In conclusion, we could estimate the level of ⊿ blood lactate from the measuring of excess CO₂.

DESCENTE SPORTS SCIENCE Vol.6/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE