The study was undertaken to determine whether acute supplementation with zinc or vitamin E would modify neuroendocrine responses to physiologic stress.Methods:
Specifically, the effects of exhaustive running on blood glucose, lactate, ACTH, cortisol, growth hormone, prolactin, catecholamine, and interleukin 6 (IL-6) concentrations were determined in 10 eumenorrheic runners after supplementation with zinc (25 mg), vitamin E (400 IU), or placebo. Subjects ran at 65-70% of their JOURNAL/mespex/04.02/00005768-199904000-00007/ENTITY_OV0312/v/2017-07-20T222658Z/r/image-pngO2max, to exhaustion, on a treadmill during the follicular phase of their menstrual cycles over three cycles.Results:
There were no significant differences associated with supplementation for any of the hormonal and metabolic measures. Exercise, however, significantly (P < 0.05) increased plasma lactate, ACTH, prolactin, and catecholamine concentrations, all of which peaked immediately after exercise (POST). Plasma cortisol concentrations were significantly (P < 0.05) elevated at POST, and a further increase was noted 1 h after exercise. IL-6 concentrations rose linearly throughout exercise and reached peak values at POST. Exercise-induced changes were transient in that all measures returned to baseline within 24 h.Conclusions:
Acute supplementation with zinc or vitamin E did not influence the effects of exhaustive running on metabolic and endocrine responses in women. The effects of chronic supplementation on neuroendocrine responses to exercise remain to be determined.