Changes in equine metabolic characteristics due to exercise fatigue.

This study investigated metabolic changes in horses due to exercise fatigue, revealing significant alterations in blood pH, levels of lactate, free fatty acids, bicarbonate, ammonia, and muscle glycogen concentrations.

Overview of Study Approach

• The research involved an exercise test performed on eight horses that were exercised to the point of fatigue.
• The exercise took place at a specific speed on a motorized equine treadmill with a given gradient.
• The study aimed to quantify changes in various metabolic factors, including blood pH, lactate, free fatty acids, bicarbonate, ammonia, and muscle glycogen concentrations.

Specific Findings

• The researchers observed significant changes in all variables from base-line values after the horses reached fatigue.
• They recorded an average heart rate of roughly 191 beats per minute at fatigue.
• Plasma lactate concentrations increased substantially from baseline values at rest to the point of fatigue.
• Ammonia concentrations doubled from before exercise to the point at which the horses were fatigued.
• Conversely, bicarbonate concentrations decreased significantly and blood pH levels also dipped.
• Free fatty acid concentrations were found to be higher at fatigue and continued to rise during the recovery period.
• A notable 25% decrease in muscle glycogen concentration in gluteus medius specimens occurred due to exercise.

Implications and Conclusion

• This study provides valuable insights into the metabolic responses to exercise in horses. Specifically, the research illustrates how exercise to the point of fatigue prompts metabolic changes, leading to increased levels of certain chemicals (i.e., lactate and free fatty acids) and decreased levels of others (i.e., bicarbonate and muscle glycogen).
• The results might prove beneficial for horse trainers and veterinary practitioners, as they could use such data to develop better training programs and health management strategies for equines.
• Further studies might build upon this baseline knowledge to understand how other variables (like diet or rest intervals) might influence these metabolic responses and potentially mitigate fatigue and its effects.