Physiological and blood biochemical variables in horses exercising on a treadmill submerged in water.

This study evaluates how exercising in water of different depths impacts horses’ blood lactate concentrations and heart rates

Summary of research

The research examined the changes in blood lactate concentration, denoted as LA, and heart rate, HR, in 10 horses while they performed exercises on a water treadmill. The treadmill was placed in water at different heights relative to the horse’s withers height (WH), and the observations were made during these exercises.

Methodology

• The exercises, called a standardized exercise test (SET), included five steps with each step lasting 5 minutes.
• Within each step, the speed of the treadmill was gradually increased.
• The water was set at 10%, 50% of the wither’s height, and at 80% of the wither’s height.
• In a different experiment, the horses executed a SET at a max attainable speed of 5.5 m/s. In this scenario, the water was adjusted at 20%, 35%, 49%, 63%, and 77% of WH in sequential steps.
• The increase in HR and LA were recorded before and after each step of the two SETs.

Results

• When the water was at 10% and 50% of the WH, the blood LA increased and reached an average of around 1.9 mm until the completion of the third step of the SET. After this step, the blood LA remained constant for the remaining duration of the exercise.
• But when the water was at 80% of WH, blood LA decreased from an average peak of 2.16 ± 0.62 mm after the completion of the fourth step of the exercise.
• The HR rose to around 132 ± 14 beats/min until the third step of the SET with water at 10% WH, up to the second step with water at 50% (134 ± 10 beats/min), and up to the first step with water at 80% of WH (134 ± 10 beats/min).
• In the experiment with a max speed of 5.5 m/s, blood LA, increased to 1.91 ± 0.25 mm until after the second step and then decreased after the third step. The HR increased between before commencing SET and the first step (143 ± 13 beats/min) and remained constant thereafter.

Conclusions

The study concluded that increasing the water level and intensifying the exercise speed didn’t consistently heighten the blood LA and HR of horses exercising on a water treadmill. By performing systematic and structured water treadmill exercises, the researchers discovered an observable physiological derivate in horses. The results suggest potential benefits, challenges, and overall health impacts that might be influenced by the different conditions of physical exercise.