Effects of pre-exercise cooling in hot environments on performance and physiological responses in Thoroughbred horses.

The research article studies the effects of pre-exercise cooling on thoroughbred horses in hot environments, demonstrating that a pre-cooling shower can help reduce body weight reduction and body temperature increase after exercising. However, it does not influence the exercising performance.

Study Background and Objective

• The study is formed on the premise that pre-exercise cooling might help prevent exertional heat illness in horses, a condition that can occur due to a rise in body temperature following strenuous activity in hot climates.
• The objective was to investigate whether pre-exercising cooling before a warm-up in a hot environment would affect the performance of the horses, and would it be effective in mitigating the reductions in weight and increases in body temperature after exercise.

Methodology

• For the experiment, six trained Thoroughbred horses were used. To obtain comprehensive results, a randomized, crossover design was used in which all horses were subjected to each treatment.
• The horses were given three pre-treatment options: a 30-minute walk on a treadmill (WALK), a 30-minute standing period (REST), and a 10-minute pre-cooling shower of 26.2 ± 0.8°C (SHOWER).
• Following each pre-treatment, the horses were warmed up and then made to exercise in a hot environment where the temperature ranged between 32-33°C.
• For the main exercise, horses were made to run on a treadmill with a 6% incline at a speed that would exhaust them within 2 minutes, corresponding roughly to 115% V̇Omax (relative intensity; 13.5-14.3 m/sec).

Results and Conclusion

• The horses which received the pre-cooling shower showed a significant reduction in weight loss when compared to the other pre-treatments.
• For the horses that underwent the WALK pre-treatment, their pulmonary artery temperatures (a measure of body temperature) after pre-treatment were significantly higher than those who received the other treatments.
• However, no significant differences were noted in heart rate, plasma lactate concentration, or the time they could run before exhaustion in any of the three treatments.
• The study concluded that pre-exercise cooling might reduce reductions in body weight and increases in body temperature, without affecting performance in hot environments. This gives a practical implication whereby it can be used to potentially protect horses from health hazards related to exercising in hot climates.