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| Author(s): |
Renato Buscariolli de Oliveira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 0000-00-00 |
| Examining board members: |
Denise Vaz de Macedo;
Fernanda Klein Marcondes;
Patricia Chakur Brum
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| Advisor: | Denise Vaz de Macedo; Rodrigo Hohl |
| Abstract | |
The use of intensified training is common in high level sport, since it can lead to increases in the performance previously achieved. This training can be manipulated through substantial increases in loads, duration, frequency, intensity, and mainly by reducing the regeneration period. On the other hand, is well documented that this intervention may result in loss of the performance level previously attained. Although there are different classifications to describe this loss of performance in athletes previously well-adapted, we used here the position adopted in 2006 by the European College of Sport Science, which called the period of intensified training of overtraining (OT) and the possible states of maintenance or improvement in the performance of Functional Overreaching (FOR), and decrease in performance of Nonfunctional Overreaching (NFOR). Due to the limitations of studying the phenomenon of the OT in human beings, we developed an animal treadmill model (Wistar rats) that takes to the states FOR and NFOR after a period of adaptation to the training (TR). The objective of the present work was to verify the relation between the state of the myocardium and the performance level of the animals submitted to the OT protocol. So, we indirectly determined the presence or not of oxidative stress (EO) in the myocardium, as well as tissue and electrophysiological alterations that could harm the cardiac function. Therefore, we made the longitudinal accompaniment of electrocardiogram (ECG) and in the end of the protocol we made the histological analysis (HE/Sirius Red); the quantification of apoptotic cells (TUNEL), dosage of TBARS (marking of lipid peroxidation) and we measured the activity of the following antioxidant enzymes:catalase (CAT), superoxide dismutase (SOD) and glutathione redutase (GR). Our results had shown that there are no alterations in the electrocardiographic parameters (ECG), in the histological analyses and in the dosage of TBARS. The GR presented a significant increase in the animals that had trained (TR, FOR and NFOR) compared to Control Group (CO) while SOD, CAT and apoptosis had significant increase only in the NFOR. The maintenance of the TBARS levels and the absence of morphologic or electrophysiological alterations that could compromise the contractile activity of the heart, indicate that the myocardium was positively adapted to the training even in NFOR. However, the increase in enzymes SOD and CAT, and the increase of apoptosis in the NFOR, indicates that the production of reactive oxygen species (EROS) seems to be greater in this group, being imminent the installation of EO. Therefore, despite the drop in NFOR performance be associated with other factors than just the involvement of the myocardium, our data show that regular physical activity with high volume should be conducted with caution and with regular assessment of cardiac function (AU) | |