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Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
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Zouhal H., Jacob C., Rannou F., Gratas-Delamarche A., Bentué-Ferrer D. *, Del P.
From the Laboratoire de Physiologie et de Biomécanique de l’Exercice Musculaire, UFR-APS, Université de Rennes II
* Laboratoire de Pharmacologie, Faculté de Médecine, Rennes, France
Background. The study investigated the concentrations of plasma catecholamine, adrenaline (A) and noradrenaline (NA), and the adrenal medulla responsiveness to the sympathetic nervous activity in sprinters (S), endurance runners (E) and untrained subjects (U) during a supramaximal exercise (the Wingate-test).
Methods. A group of 19 men took part in the tests: 6 S (20.5±0.7 years), 6 E (21.0±1.0 years) and 7 U (20.9±0.4 years). The maximal power (Wmax) and the mean power (W) were determined from the Wingate-test on a cycle ergometer. The plasma lactate, A and NA were analysed at rest (La0, A0 and NA0), immediately at the end of the exercise (Amax and NAmax) and after 5 min recovery (Lamax, A5 and NA5). The disappearance of A and NA was judged by the difference between the maximal values and those determined after 5 min recovery (Amax-A5 and NAmax-NA5) and the ratio A/NA was considered as an index of the adrenal medulla responsiveness to the sympathetic nervous activity.
Results. During the Wingate-test S exhibited higher performances and higher Lamax than the two other groups. At the end of the Wingate-test the NAmax values were similar in the three groups whereas the Amax values were significantly higher in S than in E and U (8.00±0.5 nmol·l-1 in S vs 3.47±0.30 nmol·l-1 and 3.29±1.14 nmol·l-1 respectively in E and U). This leads to a higher Amax/NAmax ratio for S compared to the other two groups (0.77±0.10 in S vs 0.23±0.03 and 0.28±0.05, respectively in E and U). As the disappearance of A (Amax-A5) was significantly higher in S (6.80±0.47 nmol·l-1 in S vs 2.64±0.19 nmol·l-1 and 1.64±1.37 nmol·l-1, respectively in E and U), the higher values of Amax in S could be explained by an increase of the adrenal medullary secretory capacity in this group.
Conclusions. It was concluded that essentially short term and intense exercises as sprint ones or interval-training may alter the adrenal medulla responsiveness to supramaximal exercise but not long duration exercises.