Determination of the optimal treadmill slope for reproducing the same cardiac response in saddle horses as overground exercise conditions.

The research investigated the optimal slope of a treadmill for horses, which would result in the same cardiovascular response as experienced during track running. The study found that a treadmill incline between 3.0 and 3.7 percent reproduced the same heart rate response as when horses were ridden on flat ground.

Research Objective and Methodology

• The study aimed to identify the best treadmill slope to reproduce the same heart rate response horses have when ridden on a flat track. This is to ensure the research or training conducted on a treadmill is as valid and applicable as it would be on a track.
• Seven French saddle horses were enlisted for this study and were subjected to physical activity under different conditions: first on a level turf track, and then on a treadmill with varying degrees of incline.
• On the track, the horses were asked to perform four periods of three-minute exercises, with speeds varying between trot and gallop (96 to 600 m/minute).
• Subsequently, the horses were put into a treadmill test where the treadmill’s slope was progressively increased in seven steps (0 to 9.6 percent) at a constant trotting speed. After a recovery period, the horses ran at five different inclines, again progressively increased, at a galloping speed.
• The heart rate of the horses was tracked through these exercises using a heart rate recorder.

Results and Findings

• The study revealed a strong correlation between heart rate and speed when horses ran on the track. Specifically, an increase in speed resulted in an increase in heart rate, indicating that heart rate could be an objective measure of physical strain in horses.
• The heart rate responses of horses running on the treadmill at different speeds and slopes were best explained by a multilinear model. This model showed a close correlation between heart rate and both speed and incline, confirming the hypothesis that both factors jointly influence a horse’s heart rate.
• Through equation analysis, the researchers found the optimal treadmill slope for achieving a heart rate response comparable to that on the track was between 3.0 and 3.7 percent.
• To validate this result, the researchers compared horses’ heart rate responses when running on a track and a treadmill set at an average incline of 3.5 percent and found them to be similar, verifying the optimal treadmill slope.