In our previous article (available here), we discussed heart rate in racehorses, Maximum Heart Rate and the value of measuring it.


The Heart Rate Trend Chart shows how the horse worked, assesses the intensity of the exercise in relation to the speed of work, and the level of recovery of the horse. These parameters quantify objectively the horse’s level of fitness, ability to exercise and fatigue.

A precise knowledge of the heart rate of your horse during training or racing makes it possible to optimize its performance and to be alerted to possible subclinical pathologies. It also allows you to better adapt the exercises to improve your horses cardio and physical performance.



The two important curves when monitoring the heart rate of a horse at exercise are the speed curve and the heart rate curve.




– A. The work zone: the speed and the heart rate are high. Quantifies the level of HR reached during the effort

B. The deceleration zone at the end of work: the speed decreases significantly but the heart rate remains high. Witness the intensity of the exercise.

C. The zone of fast reduction of the heart rate: the speed is considerably reduced and the heart rate decreases greatly. Quantifies fast recovery, recovery ability immediately after exercise.

  D. The zone of slow reduction of the heart rate: the speed is considerably reduced and the heart rate decreases slowly. Quantifies slow recovery, on the physical form.


Graph cardio entrainement


– A. The work zone


One can assess the difficulty of work by observing at what percentage of the HR Max the horse has worked and the heart rate evolution. We can define 4 main areas of work corresponding to different intensities, to train a horse in a particular zone will have a different physiological effect.

For example, if the lactic threshold is about 80% of the HR Max, working below this threshold improves the horse’s aerobic capacity and optimizes the horse’s «fitness» and endurance. In contrast, working at more than 80% requires more lactate production, which increases fatigue but stimulates metabolic adaptation and coordination in high-intensity exercises: this improves sprint power, energy and acceleration.


Influence of the working heart rate on physiological parameters

 Table 1 : Influence of the working heart rate on physiological parameters

Examples :


Heart rate horse 1 - A

Hearte rate horse 2 -A

Both horses performed the same exercise. Horse 1 reaches a peak heart rate of 212 BPM, which is 89% of its maximum heart rate (measured at 238 BPM). It is therefore a rather intense exercise especially as the effort is maintained over 1000 m.

Horse 2 reaches its maximum heart rate of 233 BPM which corresponds to 100% of its maximum heart rate. The exercise was therefore very intense for the horse, it probably would not be able to maintain a racing speed.


Unlike Horse 1, Horse 2 is not ready to race yet.


In the next article, we will discuss the deceleration zone at the end of training, the phase of rapid decrease in heart rate:”rapid recovery” and Slow heart rate decrease phase: «Slow recovery».



You can also watch the analyse of the horse heart rate frequency during training in video here: 


use Case 2 : Horse heart rate at training