Changes in plasma biochemistry in horses competing in a 160 km endurance ride.

The research is a study into the changes in plasma biochemistry in horses after taking part in a 160 km endurance ride, focusing on how speed affects the horses’ health markers.

Study Design and Participants

• The study was conducted on 14 horses, divided into two groups based on speed — the Fast Group, which completed the ride at an average speed of 234 metres per minute (m/min), and the Slow Group, which completed the ride at an average speed of 144 m/min.

Measurements and Methodology

• Plasma biochemical values were measured at multiple points: before the ride, immediately after 85 km, at the end of the 160 km ride, after a 30-minute recovery period, and the day after the ride.
• These measurements covered a wide range of biochemical markers including various electrolytes, kidney and liver function markers, muscle damage indicators, and hormones such as cortisol and insulin.

Findings and Conclusions

• The study found that endurance exercise led to disturbances in biochemical values signifying dehydration, hepatic (liver) dysfunction, reduced kidney function, and muscle damage.
• Cortisol levels, an indicator of stress, were higher in the horses that exercised at faster speeds. The Fast Group also had lower glucose levels and higher Creatine Kinase (CK) and Lactate Dehydrogenase (LD), both markers of muscle damage, than the Slow Group.
• Significantly, the biochemical values returned to their pre-ride levels the day after the ride, showing that the horses were able to recover from the strenuous exercise.

Implications of the Study

• The results show the physiological toll of endurance exercise on horses, as evidenced by various health markers. This could have implications for the care and management of horses used in high-intensity endurance activities.
• Further studies might be necessary to identify potential long-term damage or chronic conditions resulting from such activities, and how best to mitigate the risks.