Effects of coca chewing on hormonal and metabolic responses during
prolonged submaximal exercise.
Favier, Roland, Esperanza Caceres, Harry Koubi, Brigitte Sempore,
Michel Sauvain, and Hilde Spielvogel.
Instituto Boliviano de Biologia de Altura - Casilla 717, La Paz
-Bolivia, URA 1341 CNRS, Laboratoire de Physiologie, Universit_ Claude
Bernard, 69373 Lyon Cedex 08 - France, Institut Francais de Recherche
Scientifique pour le Developpement en Cooperation (ORSTOM) - Casilla
9214 - La Paz-Bolivia
APStracts 2:0428A, 1995.
The effects of coca chewing on prolonged submaximal exercise responses
were investigated in chronic coca chewers (C) and compared to a group
of non-chewers (NC). At rest, coca chewing during a one hour period
was followed by a significant increase in blood glucose, free fatty
acids and norepinephrine concentrations and a significant reduction
in insulin plasma level. During prolonged (1 hour) submaximal (65-70%
VO2peak) exercise, C displayed a significantly greater adrenergic
activation (as evidenced by a higher level of plasma epinephrine) and
an increased use of fat (as evidenced by a lower respiratory exchange
ratio). The gradual increase in oxygen uptake (O2 drift) commonly
observed during prolonged exercise was blunted in coca chewers. This
blunting in O2 drift is not related to coca-induced changes in
ventilatory or lactate responses to exercise, but could possibly be
related to an enhanced glucose utilization by C during the late phase
of exercise. The present results provide experimental evidence of the
physiological effects of coca chewing which could explain the better
ability of coca users to sustain strenuous work for an extended
period of time.
Received 6 March 1995; accepted in final form 15 September 1995.
APS Manuscript Number A250-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95