Carbohydrate supplementation of horses during endurance exercise: comparison of fructose and glucose.

The research focuses on comparing the effects of fructose and glucose, served to endurance horses as energy supplements. The study finds out that fructose is well absorbed by horses, rapidly converted to glucose, and does not significantly affect levels of insulin or glucose in the bloodstream when compared to pure glucose.

Objective of the Study

• The main objective of the study was to investigate the effects of fructose and glucose as carbohydrate supplements for endurance horses.
• The researchers wanted to establish how well each sugar is absorbed and various effects on the horses’ blood chemistry, including insulin, glucose, and lactate levels.

Methods Used

• The researchers used three Arabian geldings (male horses) and administered carbohydrate supplements of 300g, either as fructose, glucose, or a 50:50 blend of both sugars.
• The carbohydrates were dissolved in 1.5 liters of water and administered using a stomach tube.
• They performed two types of tests: A Resting Test, during which the carbohydrates were administered at rest, and an Exercise Test, entailing two treadmill exercise bouts separated by a one-hour rest period.
• The researchers took blood samples every 30 minutes for 8 hours and also collected feces for 24 hours after the treatment.

Findings

• The treatments had no effect on fecal weight or water content.
• There was no significant difference in plasma glucose and insulin responses among the treatments.
• However, plasma L-lactate levels tended to be higher 60 minutes post-treatment after the fructose and the glucose-fructose blend treatments compared with the glucose treatment.
• During the Exercise Test, plasma glucose and insulin levels at the beginning of Bout 2 were higher with the glucose-fructose blend treatment than with the fructose treatment.
• Despite this, during the exercise, plasma glucose concentrations didn’t significantly differ among the treatments.

Conclusion

• Based on this study, it can be concluded that fructose is well-absorbed by horses and is rapidly converted to glucose.
• The data indicates that fructose could be a useful carbohydrate supplement for endurance horses, given its similar effect to glucose in terms of its impact on insulin, lactate, and glucose levels.