Aug 162010

Recently I watched an episode of Monty and Kelly’s Horsemanship Essentials on Horse and Country TV. The series showcases the horse training methods of Monty Roberts and Kelly Marks. In the first part of the third episode of this series a heart monitor is worn by the horse – a lovely 3 year old Trekehner filly, while a join up and first time saddling is performed. During this episode I became increasing worried about the interpretation of the heart-rate data and I will discuss these interpretations during this article. The episode will have been seen by many viewers and therefore it is important that these factors are addressed, and furthermore I fear this misinterpretation of the heart-rate data maybe a common occurrence during join up clinics and possibly in traditional training. The purpose of this article is not, however, to discuss the pros and cons of the join-up training methodology.

The episode to be discussed can be seen at –

Firstly here is some information on heart-rate monitors and the heart-rate of the horse.

What are heart-rate monitors?

Heart rate monitors are small electrical devices usually worn on a strap around the horse’s girth. The electrodes of the monitor sitting on the skin of the horse near to the heart. The heart-rate monitor measures electrical pulses which are produced as the heart beats and either the monitor records how many times the horse’s heart beats or it transmits a signal to a receiver which records the data. During a period of time the heart-rate data is analysed and the resulting heart-rate is given as beats per minute (bpm).

What is the resting and working heart-rate of the horse?

The veterinary profession advises in almost all literature that the resting heart-rate of the mature horse should be observed to be between 28-45 beats per minute (bpm). Horses of 2 years old and younger will usually have slightly faster heart-rate and a 2 – 4 week old foal should normally have a heart-rate of between 70-90 bpm.

The horse has a maximum heart-rate of between 200 and 240 bpm, During exercise if the horse’s heart-rate is below approximately 150 bpm he will be working aerobically, above 150 bpm and the horse will be working anaerobically. During aerobic respiration the horse is relying on the oxygen available in his body to produce enough energy. However, during anaerobic respiration the horse can no longer rely on the oxygen available in his body to create enough fuel for exercise and therefore will produce energy without using oxygen once all available oxygen has be consumed.

To address the interpretation of the heart-rate data observed in the above online episode I will outline two moments in the video where heart rate is being discussed in some length and analyse the data and the interpretation.

  • 3 minutes into the video Monty says that the filly’s heart rate started at 61 bpm when she entered the round pen, rose to approximately 120 bpm during join up and then returned to a ‘resting heart rate’ of 61 bpm shortly after the follow up. A heart-rate of 61 bpm is not a resting heart-rate according to veterinary literature, should a horse have a true resting heart-rate of above 60 when the horse is in their usual environment and not exercising, it is usually highly advisable that they see a vet as it is probable that they are either chronically stressed or in pain from illness or injury. In addition it is very difficult to use this data to categorically state that the filly was not stressed by the join up. The heart-rate was higher during join up due to the exercise, it is impossible to decipher whether the horse was stressed or not during the join up using heart-rate as a measure of stress as the heart-rate will be high anyway due to the physical exertion. Interestingly, the filly’s heart-rate returned to 61 bpm and did not drop lower than this during recovery after follow up, which would imply that the filly was still not relaxed in the round-pen, although again it is difficult to decipher whether this is because of the training or because the filly is simply in an unfamiliar environment.
  • 5 minutes 50 seconds in to the episode heart-rate is briefly discussed once more, Monty states that the average heart-rate of the filly during the session was 67 bpm, but this included the join up during the start of the training when the heart-rate rose to 120 bpm. Again it is necessary to observe that 67 bpm is a high heart-rate for a horse, being approximately double a normal resting heart-rate. It should also be acknowledged that when the average heart-rate includes periods of exercise it is impossible to use the data as an indicator of stress in the horse.

Heart-rate data can be used as a measure of stress but not in conjunction with a task which requires the horse to physically exert themselves which will raise the heart-rate regardless. In addition, one should always be mindful of the standard veterinary advice on equine resting and exercising heart-rates when interpreting heart-rate data and when watching heart-rate presentations.

By Emma Lethbridge

  One Response to “Heart Rate Monitors – What can they tell us about stress in horses during training? By Emma Lethbridge”

  1. Thank you, Emma. Some sense about heart rates and their validity in clinic circumstances at last!

    I have many issues about the use of equine ‘polar monitors’ used to prove the science of certain methods. The most pertinent being that they are open to error because of being used on a horse who isn’t going to be still, in fact is going to be cantering around at some points, and the fact that there isn’t an ECG to verify the validity of the readings.

    As you point out, the resting heart rate is approximately 34 bpm, half of what was said to be the ‘resting’ heart rate of the filly.

    We should also remember that, even when stressed, our heart rates don’t tend to stay at their maximum. There is an initial peak with the surge of adrenaline but then it generally levels off albeit higher than at resting rate.

    Another point to make is that the heart rate can actually drop in response to stress as well as rise.

    I would want far more pieces of the puzzle before I accepted these findings I’m afraid.