MEASURING HEART RATE OF RACEHORSES
Why measure the heart rate of racehorses? How do you monitor data during the horse’s training? How to improve recovery to reach an excellent fitness and prepare the horse to race?
The aim of this guide is to transmit all the keys necessary to analyse the heart rate of a racehorse. Improving performance is an important subject for any trainer, owner and professional in the racing world. The arrival of data in the industry provides new key, objective and necessary information for implementing winning racing strategies.
1. HEART RATE OF RACEHORSES
Just as humans, the heart rate of a racehorse is the rhythm of his heartbeat. The cardiovascular system is made up of the heart and blood vessels. It ensures efficient blood circulation and the transport of a large volume of oxygen, mostly to the muscles. The volume of blood that the heart ejects with each beat during cardiac contraction (systolic ejection volume) is more than one litre in racehorses. The weight of the heart represents about 1% of a horse’s mass and training will tend to increase hiscardiac mass by about +15%. This improves his cardiac capacity and allows the heart to get less tired by beating more slowly for the same amount of work.
WHY IS V200 IMPORTANT
The V200 stands for the speed reached by the horse when his heart rate reaches 200 BPM. Best horses will have a higher V200 than others. However, this parameter should be used to compare trainings of the same horse than to compare horses to each other as they have different heart rates when exercising.
MAXIMAL HEART RATE (HRmax)
The maximum volume of oxygen (VO2 max) which a horse can use is one of the best indicators of his level of performance. Heart rate is strongly correlated to the volume of oxygen consumed by the body.
Once the HR Max is reached, there is little left for the horse to accelerate and reach his VO2 max. The horse has to draw on his other energy sources to be able to accelerate. However, as other sources of energy are limited in quantity during a race, horses can maintain their maximum speed for about 600 to 800 metres.
The maximum heart rate can be measured during exercise where the intensity of the requires a significant amount of energy. Typically, a maximum speed effort of 70% to 80% over at least 1600m or on a track with a positive altitude gain, or strength greater than 90% of maximum speed over 600m.
It decreases slightly with age and is very little influenced by training. Furthermore, it is not correlated with the performance level of a horse. In the same race, it has been shown that the maximum recorded heart rate of horses ranged from 204 to 241 BPM (Evans, 2007).
To gain a better understanding of the horse’s work and to train horses within their own heart rate ranges, it is advised to assess their maximum heart rate at least twice during the season using a veterinary supervised exercise test.
An exercise test is a way of identifying a horse’s working capacity by objectivising his response to training.
2. WHY AND HOW TO MEASURE THE HEART RATE OF A RACEHORSE?
ASSESS THE FITNESS LEVEL
Each racehorse has his own physical abilities. Thus, they do not all have the same limitations. Some horses naturally have the necessary breath to run a 2500m, while others are out of breath at the end of a 1200m. This is why it is essential to analyse the evolution of the heart rate at the end of each training session. It is then possible to answer the following question: is the horse really struggling to reach the finish line?
The heart rate evolution graph available on the EQUIMETRE web platform is a tool to characterise the horse’s recovery and the intensity of the training carried out. These parameters objectively quantify the horse’s fitness level, his capacity to hold an exercise and his fatigue.
A low resting heart rate (without disturbance) would be associated with a good level of fitness, whereas a high value may be associated in particular with pain, illness or fatigue linked to overtraining.
EVALUATE THE IMPACT OF A TRAINING SESSION
When a horse’s heart rate tends to remain high while the speed has dropped, it means that the training has been too intense and not well supported by the horse. Ideally, the BPM curve should fall directly with the speed curve. If this is the case, the horse is in good physical condition.
However, the heart rate does not only depend on the effort, but also on exogenous factors such as the inclination of the terrain, the weight of the rider, a change in the type or condition of the track, weather conditions, etc. In order to compare two training sessions, it is important to check that the conditions are as standardised as possible.
IDENTIFY AND PREVENT CARDIAC PATHOLOGIES
Today, high level athletes are helped in their practice thanks to the analysis of some physiological data by health professionals, allowing them to reduce the risk of pathologies such as arrhythmia and atrial fibrillation. Collecting cardiac data from race horses quickly and easily is a major asset for the racing industry in order to reduce health risks. For example, longitudinal monitoring and ECG analysis are tools to detect signs of arrhythmia and treat the horse accordingly.
Example of ECG where the horse has atrial fibrillation (ECG collected by the EQUIMETRE heart rate monitor)
Example of an ECG where the horse is in good health (ECG collected by the EQUIMETRE heart rate monitor)
EQUIMETRE is a tool that allows the horse to speak at work. Physiological parameters will be measured and these allows to know if the horse is working in comfort and safety or not. When he has difficulties in training, either because he does not have the required qualities or because he has an underlying health problem, the parameters will be in the red and will be highlighted by EQUIMETRE – and this much more than if we rely on purely subjective criteria. The idea is to put numerical values on the trainer’s impressions and see if the abnormal values are repeated over the course of training, in which case this should become a concern.
THE ARIONEO HEART RATE MONITOR AS A MEASURING TOOL
Heart rate monitor can be used to accurately measure a horse’s heart rate. This is one of the most widely used measuring instruments for sportsmen and women, and allows the heart rate to be recorded to the nearest second.
Arioneo’s heart rate monitor is made up of internationally patented electrodes specifically dedicated to the equine athlete. It enables the heart signal to be collected during the entire effort, even at full speed.
3. ANALYSE DATA TO IMPROVE RACING STRATEGIES
LONGITUDINAL FOLLOW-UP OF HEART RATE & FITNESS CONDITION
In order to compare horses over time, it is necessary to compare reliable parameters for which training will have an influence. For example, the maximum heart rate only changes very little with training, whereas the physiological adaptation leads to a decrease in heart rate at a given speed (for sub-maximal exercise).
All adaptations of the cardiovascular system are linked and some are shown in the measurement of the heart rate during exercise. Knowledge of the maximum heart rate is essential to quantify the levels of work and recovery specific to each horse. This makes it possible to define the work zones relative to the improvement of specific physiological parameters. In addition, knowledge of characteristic heart rates and recovery times can allow the evaluation of abnormal increases which may be warning signs of an incipient pathology or fatigue.
4 – HEART RATE ZONES TO BE ANALYSED TO QUALIFY YOUR HORSE’S RECOVERY
Recovery is one of the main parameters of a horse’s fitness: the better a horse’s recovery, the better his fitness. Analysed in parallel with the intensity of the work required, a horse’s fitness tells whether a horse is ready to run. An optimal fitness is shown by the ease with which a horse recovers, and therefore an excellent recovery during heavy work.
In order to analyse the evolution of a racehorse’s heart rate during training, 4 heart rate zones can be defined:
– A. The work zone: speed and heart rate parameters are high. This zone allows the HR level reached during the effort to be quantified. The difficulty of a training can be assessed by looking at what percentage of his maximum heart rate the horse has worked.
– B. The deceleration zone at the end of training: At the end of exercise, the speed decreases significantly, the heart rate must follow this decrease. However, it can remain high in order to compensate for the oxygen debt accumulated during effort.
– C. The phase of rapid decrease in heart rate – «rapid recovery»: At the end of work, after a period of heart rate maintenance (zone B) at a high level, the heart rate decreases very rapidly over a few tens of seconds (zone C). It is important to evaluate the level of return relative to the horse’s HR Max.
– D. Slow heart rate decrease phase – «Slow recovery»: The faster the horse is, the faster the horse returns to his initial heart rate. It has been shown that the recovery time (D) is correlated with the level of performance of the horse: the lower it is, the better the horse.
Nowadays, the trainer relies entirely on his experience, his feeling and the feedback from the riders. Completing this process with objective data such as heart rate and recovery maximises the efficiency of decision-making on entry and race success, while ensuring the medical follow-up of the horse.
Daily use of EQUIMETRE, based on standardised exercises, offers the possibility of monitoring the horses’ fitness level, comparing them and thus individualising training, particularly in terms of the horses’ cardiac response.
If you wish to implement connected solutions to collect cardio, speed and locomotion data, don’t hesitate to call on one of our experts!