Gastric emptying, intestinal absorption of electrolytes and exercise performance in electrolyte-supplemented horses.

This research paper focuses on the testing of an oral electrolyte supplement designed to replace the sweat electrolyte losses in horses during prolonged exercise. The findings suggest that the electrolyte supplement was quickly processed in the horses’ systems and helped increase the duration of submaximal exercise.

Study Setup

• The research involved measuring gastric emptying of the oral electrolyte supplement, absorption of sodium (Na+) and potassium (K+) ions from the gastrointestinal tract, and their distribution within the horse’s body.
• A total of 4 horses participated in the study, with observations made on radioactivity within plasma and sweat during exercise.
• Radioactive isotopes (24)Na(+) and (42)K(+) were used to trace the movement of these ions in the body.
• Each horse was given three litres of the electrolyte supplement and also underwent a placebo trial where only water was given.
• In addition, the horses were subjected to treadmill exercises at 30% of their peak oxygen uptake and their performance was monitored.

Key Findings

• The results showed that the electrolyte supplement was processed as quickly as water, with the gastric emptying half-time of around 47 minutes.
• The absorption of Na+ and K+ from the gastrointestinal tract was swift, with ions appearing in plasma 10 minutes after administration.
• Peak plasma radioactivity of (24)Na(+) and (42)K(+) was recorded at 20-40 minutes following administration.
• The quicker disappearance of K(+) radioactivity from plasma suggested the movement of K(+) into cells.
• (24)Na(+) appeared in sweat just 10 minutes into exercise, indicating a rapid distribution within the body.
• When horses received three litres of the electrolyte supplement, their duration to voluntary fatigue improved by 33 ± 10% in comparison to the placebo.

Conclusion

• The study concludes that an oral electrolyte supplement designed to replace sweat ion losses during prolonged exercise in horses is quickly emptied from the gastrointestinal tract, rapidly absorbed in the upper intestine, and swiftly distributed within the body.
• Furthermore, the electrolyte supplement acted as a reservoir to replace sweat ion losses during exercise.
• This resulted in an increased duration of submaximal exercise, making the supplement an effective means of enhancing athletic performance in horses.