Effect of the slow-component rise in oxygen uptake on VO2max

SLONIGER, MARK A.; CURETON, KIRK J.; CARRASCO, DARIO I.; PRIOR, BARRY M.; ROWE, DAVID A.; THOMPSON, RAYMOND W.

Medicine & Science in Sports & Exercise:
Basic Sciences/Regulartory Physiology: Original Investigations
Abstract

During constant-rate high-intensity (CRHI) exercise lasting longer than 3 min, ˙VO2 has been reported to exceed ˙VO2max measured with a traditional graded exercise test (GXT). This could be because˙VO2max was not achieved on the GXT or because the factors responsible for the slow-component rise in ˙VO2 alter˙VO2max. The objective of this study was to test the hypothesis that the slow-component rise in ˙VO2 measured during CRHI running leads to a total ˙VO2 that exceeds ˙VO2max measured during a running GXT. ˙VO2max was determined in eight highly trained individuals using data collected from five grade-incremented, treadmill-running GXT. Each subject demonstrated a definitive plateau of˙VO2 as a function of exercise intensity. Three ˙VO2max values based on different approaches for representing the ˙VO2max plateau were obtained. Subjects also completed two exhaustive CRHI bouts of treadmill running lasting 7-13 min at speeds estimated from the ACSM equation to elicit an average of 99 ± 5% ˙VO2max. The mean(±SD) ˙VO2peak determined during the CRHI runs (4.17± 0.9 l·min-1) was not different from or less than the three ˙VO2max values (4.19-4.32 ± 0.09 l·min-1). We conclude that in highly trained individuals, the slow-component rise in ˙VO2 during CRHI treadmill running does not lead to a total ˙VO2 that exceeds the ˙VO2max measured during a running graded exercise test.

Author Information

Department of Exercise Science, The University of Georgia, Athens, GA 30602-3654

Submitted for publication August 1994.

Accepted for publication August 1995.

Address for correspondence: Mark A. Sloniger, Department of Exercise Science, Physical Education Building, University of Georgia, Athens, GA 30602-3654; E-mail: sloniger@uga.cc.uga.edu.

©1996The American College of Sports Medicine