Potential markers of heavy training in highly trained distance runners.

Abstract

Markers of a heavy increase in training were examined in ten highly trained distance runners (mean(s.d.) age 29.8(1.7) years, maximal oxygen intake 65.3 ml kg-minu-, personal best 10-km time 31 min 4s) who undertook a deliberate 38% increment of training over a 3-week period. Their running performance did not improve, and six of the ten subjects developed sustained fatigue, suggesting that training was excessive, although the full clinical picture of overtraining did not develop. The Profile of Mood States was the best single marker of disturbed function, indicating increased fatigue and decreased vigour. There were no useful changes of resting heart rate or perceived exertion during submaximal running, sleep was undisturbed, and there were no orthopaedic injuries. Two subjects developed rhinoviral infections following the heavy training, and a third complained of symptoms that were diagnosed 2 weeks later as exercise-induced asthma. The increase of serum cortisol normally induced by 30 min of submaximal exercise was no longer seen when the same acute exercise was performed after heavy training. Resting lymphocyte proliferation tended to increase in response to phytohaematoglutinin (PHA) and concanavalin A (Con A), the ratio of helper to suppressor cells (H/S) decreased, and pokeweed mitogen induced smaller increases in IgG and IgM synthesis. Whereas before heavy training, PHAstimulated lymphocyte proliferation was unchanged by 30 min of acute submaximal exercise, after 3 weeks of heavy training the same bout of exercise caused an 18% suppression of proliferation. Likewise, heavy training brought about a decrease of T-lymphocytes in response to acute submaximal exercise, but an abolition of the acute exercise-induced decrease in the HIS ratio. The previously observed exercise-induced decrease of IgG synthesis did not occur when the same acute bout of exercise was performed after heavy training. We conclude that such minor and transient changes of immune function may possibly be a warning that training is becoming excessive, but they have only a limited significance for overall immune function.

Overview of the epidemiology of exercise immunology

“…In some instances, the incidence of infection has simply been compared with expectations for the general population. [33][34][35] In other studies, a comparison has been drawn with the experience of the same subjects prior to competition, 36,37 before augmenting physical training, 38,39 before augmenting the aerobic training mileage 32,40 or before an increase of fitness level. 41 In all reports where subjects have served as their own controls, findings are vulnerable to seasonal and secular trends in the incidence of infection.…”

Compreendendo o overtraining no desporto: da definição ao tratamento

“…c) Razão Testosterona/Cortisol (T/C): Adlercreutz et al [1] propuseram que a diminuição superior a 30% na razão T/C indicaria o estado de OT. Embora alguns estudos tenham constatado alterações na razão T/C durante períodos de treinamento intenso [40,88], a maioria dos pesquisadores não verificou tais alterações em uma série de atletas incluindo corredores [20,23,86] e nadadores [20,33,40]. Além disso, alguns estudos verificaram queda igual ou superior a 30% na razão T/C, que correspondeu com ganho de performance [19,32].…”

Operator Functional State Assessment (L'evaluation de l'aptitude operationnelle de l'operateur humain)

“…The overtraining syndrome has been associated with high resting blood or salivary levels of cortisol in some studies (Barron et al, 1985;Neary, Wheeler & McLean, 1994;O'Connor, Morgan, Raglin, Barksdale & Kalin, 1989) but not in others where cortisol was found to decrease (Lehmann, Foster, & Keul, 1993; or to not change (Flynn, Pizza & Boone, 1994;Hooper, et al, 1993;Verde, Thomas & Shepard, 1992).…”