Instructions for use Title Relationship Between Ventilation and Predicted Arterial CO2 Pressure During Recovery From an Impulse-Like Exercise Without Metabolic Acidosis

We investigated ventilation (V ． E) control factors during recovery from light impulse-like exercise (100 watts) with a duration of 20 s. Blood ions and gases were measured at rest and during recovery. V ． E, end tidal CO 2 pressure (PETCO 2) and respiratory exchange ratio (RER) were measured continuously during rest, exercise and recovery periods. Arterial CO2 pressure (PaCO 2 pre) was estimated from PETCO 2 and tidal volume (V T). RER at 20 s of exercise and until 50 s during recovery was significantly lower than RER at rest. Despite no change in arterialized blood pH level, PaCO 2 pre was significantly higher in the last 10 s of exercise and until 70 s during recovery than the resting value. V ． E increased during exercise and then decreased during recovery; however, it was elevated and was significantly higher than the resting value until 155 s (p<0.05). There was a significant relationship between V ． E and PaCO 2 pre during the first 70 s of recovery in each subject. The results suggest that PaCO 2 drives V ． E during the first 70 s of recovery after light impulse-like exercise. Elevated V ． E in the interval from 70 s until 155 s during recovery might be due to neural factors.