Endurance exercise, plasma oxidation and cardiovascular risk

Area of Science:

• Cardiovascular Health
• Exercise Physiology
• Oxidative Stress Research

Background:

• Regular physical activity is crucial for health, but prolonged high-intensity exercise may elevate cardiovascular risks.
• Aerobic exercise can increase oxidative stress, potentially promoting atherosclerosis through enhanced oxidation of plasma lipoproteins.

Purpose of the Study:

• To investigate the association between aerobic power and oxidative stress markers.
• To assess plasma's susceptibility to oxidation in relation to aerobic capacity.

Main Methods:

• Evaluated 24 healthy men, categorizing them into high aerobic power (HAP) and lower aerobic power (LAP) groups based on VO2max.
• Analyzed plasma for total antioxidant capacity (TAC), malondialdehyde (MDA), and susceptibility to oxidation using three distinct measures.
• Quantified plasma oxidizability via lag time to conjugated diene formation, change in absorbance at 234 nm, and the slope of the oxidation curve.

Main Results:

• HAP subjects exhibited significantly lower TAC and a higher change in absorbance compared to LAP subjects.
• No significant difference in malondialdehyde (MDA) levels was observed between the HAP and LAP groups.
• A significant inverse correlation was found between TAC and the slope of the oxidation curve, indicating higher oxidizability.

Conclusions:

• Individuals with high aerobic power, often resulting from extreme endurance training, demonstrate diminished plasma antioxidant capacity.
• These individuals also show increased susceptibility of their plasma to oxidation.
• The findings suggest a potential elevation in cardiovascular risk among those with very high aerobic power due to these oxidative stress markers.