Equine sweat composition: effects of adrenaline infusion, exercise and training.

The research article investigates how adrenaline infusion, exercise, and training alter the electrolyte composition of sweat in horses. The study shows that sweat produced during these conditions is highly concentrated, and its composition does not significantly change, even after training. However, the concentration of sodium and chloride in sweat increases with the duration of sweating.

Objective of the Research

• The main aim of this research was to study the effects of adrenaline infusion, exercise, and training on the composition of horse sweat. The research sought to understand how these factors alter the electrolyte concentrations in sweat. It was also interested in how sweat composition changes after consistent training.

Methodology

• The study was conducted on 10 horses undergoing a 10-week training programme. Five of these horses were subjected to moderate-intensity training to speeds of 10 m/s, and the other 5 to low-intensity training to speeds of 5 m/s.
• Sweat was collected from two different sites on these horses. The first occasion was during a submaximal exercise test where the horses were made to exercise for 30 minutes at 50% of their maximum oxygen consumption (VO2 max). The second occasion was during an adrenaline infusion, where adrenaline was infused at a dose mean of 0.3 g/kg over 30 minutes.
• The collected sweat samples were then analyzed for various components, including sodium, chloride, potassium, protein, magnesium, calcium, and urea concentrations.

Findings

• The study observed that the sweat produced in response to both exercise and adrenaline infusion was hypertonic, meaning it had a higher concentration of electrolytes than normal.
• No significant differences were found in the sweat composition following the training period, indicating that training did not significantly affect the electrolyte composition of sweat.
• The concentration of sodium chloride ([NaCl]) in the sweat increased as the duration of sweating increased.
• The sweat produced in response to adrenaline infusion was more dilute than that produced in response to exercise, suggesting that the body’s sympathetic system’s response during exercise might cause this difference.

Conclusion

• The research suggests that both exercise and adrenaline infusions alter the electrolyte composition of sweat in horses, making it more concentrated. Even with regular training, this composition does not significantly change. However, the longer a horse perspires, the higher the sodium and chloride concentration in the sweat. Additionally, the study shows a difference in sweat concentration in response to adrenaline infusion and exercise.