Antioxidant capacity and athletic condition of endurance horses undergoing nutraceutical supplementation

Endurance is an equestrian discipline that primarily relies on aerobic metabolism. Intense aerobic exercise produces reactive oxygen species due to an imbalance between oxidant and antioxidant substances, known as oxidative stress, which may reduce athletic performance. This study evaluated the effects of a feed supplement containing natural antioxidants and omega-3 fatty acids on the blood antioxidant activity and the athletic condition of endurance horses undergoing an exercise test. Twelve Arabian endurance horses were randomly assigned to treatment or control groups. At T0, blood lactate, whole blood and red blood cells (RBC) antioxidant capacity were assessed. The horses performed an exercise test with heart rate monitoring. After 30 min, blood lactate, antioxidant capacity and serum creatine kinase (CK) were measured. The treatment group received the dietary supplement for 21 days, while controls maintained their diet. Then, the protocol was repeated (T1). Variables were compared within and between groups through two-way ANOVA and post-hoc tests. Significant time*group effects were observed for serum CK (p = 0.026), RBC antioxidant capacity at rest (p = 0.034) and post-exercise (p = 0.019). At T1, in treatment group, CK was lower than controls (p = 0.006), while RBC antioxidant capacity increased at rest (p = 0.037) and after exercise (p = 0.006) compared to T0. The dietary supplement showed efficacy in enhancing RBC antioxidant capacity, and it could be beneficial for horses engaged in intense aerobic exercise.