Oxidative Stress After Three Different Intensities of Running

Abstract

In 8 trained subjects (T) and 9 untrained subjects (UT), lipid peroxidation (LPO), total antioxidant capacity (TRAP), superoxide dismutase, catalase, and glutathione peroxidase (GPx) activities were measured in the blood before and after three different intensities of exercise on the treadmill, determined from ventilatory threshold and maximal oxygen uptake data, obtained from a maximal aerobic power test. In plasma, LPO decreased from 3589 +/- 193 to 3274 +/- 223 cps x mg Hb(-1) (p < 0.05), and TRAP increased from 304 +/- 45 to 384 +/- 57 micromol x L(-1) trolox (p < 0.05) after high intensity exercise in T. GPx activity increased in the T group as compared to the UT group, after exercise in moderate (25.90 +/- 3.79 to 15.05 +/- 3.23 nM x min(-1) x mg protein(-1)) and high (21.75 +/- 4.91 to 12.1 +/- 2.46 nM x min(-1) x mg protein(-1)) intensities (p < 0.05). Superoxide dismutase activity increased after exercise at low (8.35 +/- 0.85 to 9.23 +/- 1.03 U SOD x mg protein(-1)) and moderate (8.89 +/- 0.98 to 10.44 +/- 0.86 U SOD x mg protein(-1)) intensity in UT (p < 0.05). There were no changes in catalase activity. These findings indicate that exercise in this model did not increase lipid peroxidation, probably because of the alterations in TRAP and enzymatic antioxidants.

Aspectos atuais sobre estresse oxidativo, exercícios físicos e suplementação

“…Although acute sessions of anaerobic exercises increase the ORS synthesis, with consequent appearance of injuries, in a situation of chronic training favorable adaptations to the antioxidant system may occur (14,19) . Individuals trained in activities predominantly anaerobic present a reduced anaerobic stress and a lower number of injuries, when compared with non-trained individuals (27,29,31) . Hellsten et al (28) have examined the effects of explosion training over the activity of some antioxidant enzymes, including the glutathione peroxidase (GPx), glutathione redutase (GR) and the superoxide dismutase (SOD).…”

“…Although the protocols are fairly diversified and vary according to each sport, many studies demonstrate a significant increase of oxidative stress in exercises with supramaximal intensities (27)(28)(29)(30) . Figure 2 -Mechanisms of the ORS synthesis during and post-anaerobic exercises VO 2máx = O 2 maximum volume.…”

“…Processo inflamatório** The increase of the ORS synthesis in anaerobic exercises may occur in different ways, such as the activation of the electrons transportation chain, the increased synthesis of the xantine oxidase and NADPH oxidase enzymes, the prolonged ischemia process and tissue reperfusion and the phagocyte activity (figure 2) (11,27,31) . Additionally, the increase of the lactic acid synthesis, catecholamine and the increased inflammatory process after anaerobic exercises with supra-maximal intensities also significantly contribute to the ORS production (31) .…”

“…The moment the tissue is reperfunded, that is, during muscular relaxation, the 2+ , it used the O 2 , which accepts electrons and becomes steady. The role of the xantine oxidase enzyme in the ORS synthesis during exercises is not clear yet and further studies should be conducted (27) . Although acute sessions of anaerobic exercises increase the ORS synthesis, with consequent appearance of injuries, in a situation of chronic training favorable adaptations to the antioxidant system may occur (14,19) .…”

Níveis de beta-endorfina em resposta ao exercício e no sobretreinamento

“…Por outro lado, o exercício induz a adaptações positivas que protegem o organismo dos danos gerados pelos RLO, como demonstrado em nossos estudos (69,70), apresentando maior atividade da enzima glutationa peroxidase em triatletas comparados com indivíduos não-treinados e capacidade antioxidante total plasmática (TRAP) aumentada em ambos os grupos. Entretanto, o treinamento crôni-co pode interferir no sistema antioxidante, gerando desequilíbrio entre a produção de RLO e a resposta antioxidante, causando, assim, estresse oxidativo crôni-co ou resposta inflamatória sistêmica induzida por estresse oxidativo, que pode diminuir o desempenho físico e levar ao desenvolvimento do ST (10).…”