Journal of Applied Physiology, Vol 67, Issue 5 1862-1867, Copyright © 1989 by American Physiological Society
Effect of induced alkalosis on perception of exertion during intermittent exercise
A. Swank and R. J. Robertson
Exercise Physiology Laboratory, University of Louisville, Kentucky 40292.
The purpose of this study was to evaluate the effects of metabolic
alkalosis on differentiated ratings of perceived exertion during
intermittent high-intensity exercise. Six endurance-trained females
participated as subjects in this investigation. Each subject underwent
three separate experimental trials in which NaHCO3 was ingested in either a
single (0.3 g NaHCO3/kg body wt) or periodic schedule (0.12 g NaHCO3/kg
body wt initially, with 0.18 g/kg body wt distributed in equal doses before
each 5-min exercise bout). Calcium carbonate served as a placebo control.
An intermittent exercise protocol was used in which each subject rode a
cycle ergometer at 90% maximum O2 consumption for 5 min. Within each
acid-base condition, the exercise protocol was repeated three times with
10-min rest periods interspersed. Differentiated ratings of perceived
exertion for the legs (RPE-L), chest (RPE-C), and overall body (RPE-O) were
attenuated under alkalotic treatment relative to placebo control regardless
of pattern of NaHCO3 administration. RPE-L, RPE-C, and RPE-O were
negatively correlated to the bicarbonate concentration of venous blood.
This investigation suggests that perception of effort during high-intensity
intermittent exercise can be related to buffering capacity of the blood.
