Acute plasma volume expansion: effect on metabolism during submaximal exercise. Watt, Matthew J., Mark A. Febbraio, Andrew P. Garnham and Mark Hargreaves. 1School of Health Sciences, Deakin University, Burwood, 3125; 2Department of Physiology, The University of Melbourne, Parkville, 3052, Australia.
APStracts 6:0252A, 1999.
To examine the effect of acute plasma volume expansion (PVE) on substrate selection during exercise, seven untrained men cycled for 40 min at 72 ( 2% peak on two occasions. On one occasion subjects had their plasma volume expanded by 12 ( 2% via an intravenous infusion of the plasma substitute Haemaccel(, while on the other no such infusion took place. Muscle samples were obtained prior to and immediately following exercise. In addition, heart rate, pulmonary gas and venous blood samples were obtained throughout exercise. No differences in oxygen uptake or heart rate during exercise were observed between trials, whilst RER, blood glucose and lactate were unaffected by PVE. Muscle glycogen and lactate concentrations were not different either prior to or following exercise. In addition, there was no difference in total carbohydrate oxidation between trials (CON: 108 ( 2 g; PVE: 105 ( 2 g). Plasma catecholamine levels were not affected by PVE. These data indicate that substrate metabolism during submaximal exercise in untrained men is unaltered by acute hypervolemia. 

Received 30 October 1998; accepted in final form 1 June 1999.
APS Manuscript Number A985-8.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 14 June 1999