VO2 kinetics and the O2 deficit in heavy exercise

Department of Nutrition, Food, and Exercise Science, The Florida State University, Tallahassee, Florida 32306 The purpose of this study was to examine a new method for calculating the O 2 deficit that considered the O 2 uptake ( O 2 ) kinetics during exercise as two separate phases in light of previous research in which it was shown that the traditional O 2 deficit calculation overestimated the recovery O 2 consumption (ROC). Eight subjects completed exercise transitions between unloaded cycling and 25% (heavy, H) or 50% (very heavy, VH) of the difference between the lactic acid threshold (LAT) and peak O 2 for 8 min. The O 2 deficit, calculated in the traditional manner, was significantly greater than the measured ROC for both above-LAT exercises: 4.03 ± 1.01 vs. 2.63 ± 0.80 (SD) liters for VH and 2.36 ± 0.91 vs. 1.74 ± 0.63 liters for H for the O 2 deficit vs. ROC ( P