Effect of exercise on blood oxidant/antioxidant markers in standardbred horses: comparison between treadmill and race track tests.

The research article presents a comparative study on the impact of exercise-induced stress on the oxidant/antioxidant balance in blood, looking at treadmill (TM) and race track (RT) tests in trained Standardbred horses. It concludes that although both tests led to changes in the blood oxidant/antioxidant balance, the treadmill tests had a stronger impact.

Objective

• The key objective of the research was to examine the effects of strenuous exercise on the oxidant/antioxidant status of healthy, trained Standardbred horses and to compare the results obtained from two different exercise regimens – running on a treadmill and running on a race track.

Methods

• Exercise tests were conducted both on a treadmill and a race track, and blood samples were collected pre and post-exercise.
• The horses’ average running time to fatigue (RTF), velocity during the last exercise stage (Vmax), final heart rate (HRfinal), and venous lactic acid (LA) were recorded.
• Several biochemical markers were analysed in the blood samples to determine the oxidant/antioxidant status, including uric acid (UA), ascorbic acid (AA), superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), oxidised glutathione (GSSG), glutathione redox ratio (GRR), and protein thiol (PSH).

Results

• Significant increase in UA and AA were noted post-exercise in both treadmill and track tests, while GSH and PSH significantly decreased post-exercise in both settings.
• Other markers such as GPx, SOD, GSSG, and GRR remained unchanged.
• The velocity during the last exercise stage was higher on the race track while venous lactic acid was lower after the race track test.
• Final heart rate and running time to fatigue did not vary significantly between the treadmill and the race track tests.
• The treadmill test triggered stronger changes in blood lactate and oxidant/antioxidant balance compared to the race track test.

Conclusions

• Attempts to compare antioxidant/oxidant profiles from laboratory and field studies come with challenges and the results should be interpreted with caution.
• The results indicate that exercise type and intensity can indeed influence the blood oxidant/antioxidant balance in horses, emphasizing the need to consider the test setting when interpreting results.