PT  - JOURNAL ARTICLE
AU  - António Ascensão
AU  - Rita Ferreira
AU  - Franklim Marques
AU  - Eduardo Oliveira
AU  - Victor Azevedo
AU  - José Soares
AU  - José Magalhães
TI  - Effect of off-road competitive motocross race on plasma oxidative stress and damage markers
AID  - 10.1136/bjsm.2006.031591
DP  - 2007 Feb 01
TA  - British Journal of Sports Medicine
PG  - 101--105
VI  - 41
IP  - 2
4099  - http://bjsm.bmj.com/content/41/2/101.short
4100  - http://bjsm.bmj.com/content/41/2/101.full
SO  - Br J Sports Med2007 Feb 01; 41
AB  - 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.