Dissociation of peak vascular conductance and o2max among highly
-trained athletes.
Hepple, Russell T., Thomas L. Babits, Michael J. Plyley and Jack M.
Goodman.
1Department of Medicine, 0623A, University of California-San Diego,
La Jolla, CA 92093-0623, USA; 2Faculty of Physical Education and
Health, and Graduate Department of Exercise Science, University of
Toronto, Toronto, Ontario M5S 2W6, Canada
APStracts 6:0280A, 1999.
Previously, a strong relationship has been found between whole body
O2max and peak vascular conductance in the calf muscle (19,25)_,
suggesting a matching between maximal exercise capacity and
peripheral vasodilatory reserve across a broad range of aerobic
power. In contrast, long-term training could alter this relationship
due to the unique demands for muscle blood flow and cardiac output
imposed by different types of training. In particular, the high local
blood flows but relatively low cardiac output demand imposed by the
type of resistance training used by body-builders may cause a
relatively greater development in peripheral vascular reserve than
aerobic power. To examine this possibility, we studied the
relationship between treadmill O2max and vascular conductance in the
calf using strain-gauge plethysmography following maximal ischemic
plantar-flexion exercise in 8 healthy sedentary (HS) subjects, and 28
athletes. These athletes were further divided into three groups: 10
elite middle distance runners (ER), 11 power athletes (PA), and 7
body-builders (BB). We found that both BB and ER deviate from the
previously demonstrated relationship between O2max and vascular
conductance. Specifically, for a given vascular conductance, BB had a
lower O2max, whereas ER had a higher O2max than HS and PA. We
conclude that the relationship between peak vascular conductance and
aerobic power is altered in BB and ER due to training-specific
effects on central versus peripheral cardiovascular adaptation to
local skeletal muscle metabolic demand.
Received 5 February 1999; accepted in final form 27 May 1999.
APS Manuscript Number A084-9.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 25 June 1999