Journal of Applied Physiology, Vol 72, Issue 3 1201-1204, Copyright © 1992 by American Physiological Society
Effect of 5 wk of detraining on epinephrine response to insulin-induced hypoglycemia in athletes
M. Kjaer, K. J. Mikines, M. V. Linstow, T. Nicolaisen and H. Galbo
Department of Internal Medicine, Rigshospitalet, Copenhagen, Denmark.
Long-term endurance-trained subjects are known to have an enhanced capacity
to secrete epinephrine. It is, however, unknown to what extent this is a
reversible phenomenon, i.e., whether the adrenal medullary secretory
capacity is diminished during a period of abstinence from training.
Hormonal responses to insulin-induced hypoglycemia were studied in seven
endurance-trained young male athletes at the onset and the termination of a
31- to 44-day period of detraining necessitated by a sports injury that
required leg casting. During insulin infusion, plasma glucose decreased to
a mean range of 2.0-2.1 mM for the two conditions. The epinephrine response
to hypoglycemia did not decrease significantly during the 4-6 wk of
detraining (P greater than 0.05). Responses of other counterregulatory
hormones, i.e., norepinephrine, glucagon, growth hormone, and cortisol,
were identical in trained and detrained subjects (P greater than 0.05).
Heart rate and blood pressure responses to hypoglycemia were similar in the
two conditions (P greater than 0.05). In conclusion, in endurance athletes
the enhanced capacity to secrete epinephrine is maintained during 5 wk of
detraining.
