Effects of sodium bicarbonate on cardiorespiratory measurements and exercise capacity in thoroughbred horses.

The research article presents a study investigating the impact of sodium bicarbonate on cardiorespiratory functions and exercise capacity in thoroughbred horses during various intensities of treadmill exercise. The results indicate that sodium bicarbonate administration improves exercise capacity and influences arterial gas concentrations.

Introduction and Methodology

• The study engaged six Thoroughbred horses and subjected them to both submaximal and maximal treadmill exercises to understand the effect of sodium bicarbonate on their cardiorespiratory functions and exercise capacity.
• Researchers primarily focused on the assessment of cardiorespiratory function and exercise capacity by measuring the run-time to fatigue point at maximum intensities.
• For control purposes and to distinguish between the alkalinising effects of sodium bicarbonate and potential fluid shifts caused by its high osmotic load, the horses were also given an equimolar solution of sodium chloride (commonly known as saline).
• The administration of the substances was done via a nasogastric tube, with the doses being 1g/kg bwt of sodium bicarbonate or an equivalent number of moles of sodium chloride.

Data Collection

• Arterial blood samples from the horses were collected both before the exercise and five hours post-treatment. Mean standard bicarbonate values obtained were higher in sodium bicarbonate treated horses (39.6 mmol/l) as opposed to those treated with saline (24.2 mmol/l).
• The exercise routine for the horses was designed to include treadmill exercise at 40, 60 and 80% of their maximum oxygen consumption (VO2max) for varying minutes, along with a speed acceleration to approximately 110% VO2max, maintained until the horses reached fatigue.

Results and Conclusion

• The administrative sodium bicarbonate led to an increased run time, recorded as 170 +/- 20 secs versus 128 +/- 13 secs with sodium chloride, demonstrating an improvement in exercise capacity.
• At rest, submaximal and maximal exercise, bicarbonate-treated horses showed significantly lower arterial oxygen tensions and higher arterial carbon dioxide tensions.
• No significant differences were observed in terms of cardiac output, heart rate, oxygen uptake or carbon dioxide production between the two groups (saline and bicarbonate treatments).

Implications

• The study thus provides evidence that sodium bicarbonate can effectively enhance exercise capacity and alter arterial gas concentrations in thoroughbred horses, opening possibilities for its potential use to improve performance in equine athletes.