Sports Med 2006; 36 (5): 429-441

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 1. Reactive Oxygen Species (ROS) and Oxidative Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 2. Mechanism of Exercise-Induced ROS Production and Oxidative Damage . . . . . . . . . . . . . . . . . . . . 430 3. Minimising Oxidative Stress: the Antioxidant Defence System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 4. Direct Evidence of Exercise-Induced Oxidative Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 5. Limitations of the Indirect Measurement of Oxidative Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 6. Indirect Evidence of Exercise-Induced Oxidative Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 7. Low-Density Lipoprotein Oxidation and Exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 8. Exercise/Physical Activity, Energy Expenditure and Morbidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 9. Ultra-Endurance Athletes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 10. Ultra-Endurance Exercise and Cardiovascular Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 11. Ultra-Endurance Exercise and Oxidative Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 12. Exercise Training, Adaptations and Oxidative Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 13. Exogenous Antioxidants, Ultra-Endurance Exercise and Oxidative Stress . . . . . . . . . . . . . . . . . . . . . . 437 14. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 At least 30 minutes of moderate-intensity physical activity accumulated on Abstract most, preferably all days is considered the minimum level necessary to reduce the risk of developing cardiovascular disease. Despite an unclear explanation, some epidemiological data paradoxically suggest that a very high volume of exercise is associated with a decrease in cardiovascular health. Although ultra-endurance exercise training has been shown to increase antioxidant defences (and therefore confer a protective effect against oxidative stress), an increase in oxidative stress may contribute to the development of atherosclerosis via oxidative modification of low-density lipoprotein (LDL). Research has also shown that ultra-endurance exercise is associated with acute cardiac dysfunction and injury, and these may also be related to an increase in free radical production. Longitudinal studies are needed to assess whether antioxidant defences are adequate to prevent LDL oxidation that may occur as a result of increased free radical production during very high volumes of exercise. In addition, this work will assist in understanding the accrued effect of repeated ultra-endurance exercise-induced myocardial dam-