IJUP08 - Universidade do Porto

Physical exercise and stress hormones
M. Moz 1 , S. Baptista 1 , O. Cardoso 1 , M. Mendanha 1 , A. Ascensão 2 , J. Magalhães 2 and
L. Ribeiro 1
1 Department of Biochemistry, Faculty of Medicine, University of Porto, Portugal.
2 Department of Sport Biology, FCDEF, University of Porto, Portugal.
An adequate balance between catabolic processes (mobilization of energy), induced by
stress hormones such as the catecholamines (CA), adrenaline (AD) and noradrenaline (NA)
and cortisol, and anabolic processes (repair, healing, growth), induced by steroid sex (such
as testosterone) and growth hormones, is vital for health and survival [1].
Regular moderate physical exercise is known to contribute to such anabolic effects and to
an earlier homeostasis restoration [2]. However, long-term and/or excessive physical
exercise result in the over-secretion of CA and cortisol, leading to over-reaction and
exhaustion of the target-organs, which can be extremely harmful. Acute or chronic stress,
induced by excessive physical exercise, may thus lead to an inadequate endocrine
response, eventually contributing as a risk factor to disease initiation and/or exacerbation
[3].
The aim of our work was to examine the effect of exposure to an intense and extremely
stressful training on several plasma stress hormone levels in healthy male individuals. Two
groups were evaluated: one group of individuals conditioned by a previous 3 months
rigorous training (Group A; n=7) and another one not submitted to this training (Group B;
n=7). Blood samples were collected before (basal), immediately after 72 hours of the
training and 48 hours (rest period) after this period. AD and NA levels were quantified by
means of high pressure liquid chromatography with electrochemical detection (HPLC-ED)
and plasma cortisol and testosterone levels by RIA..
There were no significant differences between groups A and B, relatively to basal levels, of
either cortisol (13.4±1.64 vs. 14.7±1.1 µg/dL) or testosterone (136.6±40 vs. 176.7±40
ng/dL). After training, there was an increase of cortisol plasmatic levels, which was though
only significant for group A. However, after 48 hours of rest, cortisol levels remained high
in group B, but not in A (p