Citation

Ascensão A, Ferreira R, Marques F, Oliveira E, Azevedo V, Soares J, Magalhães J. Br. J. Sports Med. 2007; 41(2): 101-105.

Affiliation

Research Center in Physical Activity, Health and Leisure, Faculty of Sports Sciences, University of Porto, Porto 4200-450, Portugal. aascensao@fcdef.up.pt

Copyright

(Copyright © 2007, BMJ Publishing Group)

DOI

10.1136/bjsm.2006.031591

PMID

17138632

PMCID

PMC2658913

Abstract

AIM: To analyse the effect of an off-road motocross heat on plasma levels of oxidative stress and damage, blood leucocyte counts and urine catecholamine concentration. METHODS: Plasma contents of total, reduced and oxidised (GSSG) glutathione, %GSSG, malondialdehyde (MDA), protein carbonyl and sulphydryl groups, total antioxidant status (TAS), uric acid, and blood neutrophil and lymphocyte counts were evaluated in 10 male top-level riders before, immediately after (0 h) and 1 h after a simulated competitive motocross race. 24-h urine adrenaline, noradrenaline and dopamine concentrations were also measured. RESULTS: The motocross heat resulted in an increase in plasma oxidative stress and damage (p<0.05). This was shown by a significant increase in %GSSG, TAS, MDA and carbonyls, and by a decrease in sulphydryl groups after the race. There was a significant increase in both plasma uric acid and urine catecholamine concentration after the race (p<0.05). Blood neutrophil counts increased at 0 and 1 h after exercise (p<0.05). Lymphocyte count increased from baseline to 0 h, although it decreased from baseline and 0 to 1 h after exercise (p<0.05). CONCLUSION: The data reinforce the marked metabolic and hormonal demands imposed by motocross, resulting in a condition of enhanced plasma oxidative stress and damage.

Language: en