Part 1 - How and why should we monitor exercise recovery?

Recovery - Part 1

How and Why Should We Monitor Exercise Recovery?

When we think of competing our horses, our focus and attention is usually drawn to the ridden performance that we aim to achieve. This may be perfecting jump technique, the perfect half-pass or monitoring the length, frequency and type of sessions. However, when it comes to monitoring the horse’s fitness and progress, there is another significant factor to measure to help achieve a top performance.

Depending on whether the horse is performing at home or away, there are a number of factors that could contribute to your horse’s fatigue after competition. These include the physical and psychological stresses of travelling, the additional presence of hormones such as cortisol and adrenaline as a result of a new environment and the exercise itself regardless of discipline. It then relies on us as horse owners to help our horse recover from these stressors to ensure the horse’s mind and body repairs well enough for future performances. In the first part of our recovery blog series we investigate the mechanisms behind exercise recovery and how we can monitor it in our horses.

What is recovery?

Recovery refers to a number of post-exercise effects that occur within the body, including tissue and muscle damage, fatigue, glycogen depletion and reduced immunity [1,2]. In order to remain healthy and continue to exercise and perform well in the future, adequate time should be allowed for healing. Failure to do so before the next competition or even before travelling home from the same competition could result in electrolyte and nutritional imbalance, muscle soreness and dehydration which could give rise to an episode of tying-up, colic or respiratory disease [2].

What happens to the horse's body when they exercise?

When the horse exercises, it requires recruitment of all the main systems; skeletal, muscular and cardiovascular. During exercise, tissue damage occurs at a cellular level and this process of microscopic damage and repair is the process in which tissues are strengthened [18]. Due to muscle exertion, lactic acid accumulates in the muscles, ATP and sometimes glycogen energy stores are depleted and large quantities of water are lost through sweating and breathing effort [10]. Therefore, there are many steps to take in order to return the horse to good condition after exertion.

How can we monitor recovery?

Heart Rate

There are a number of ways in which we can monitor a horse’s recovery but the most commonly used is heart rate. This is because the heart is responsible for delivering blood and removing by-products around the body, both of which contribute to helping the horse’s body return to their pre-exercising resting state. A frequent measurement of fitness, stress and overall health [6,7,8], heart rate is one of the most important and useful parameters to measure for recovery [5,4,9].  

The speed at which the heart rate returns to resting level following exercise is therefore one of the best indicators to measure the effect of exercise intervals and level of fitness. Endurance horses, for example must reach a heart rate of less than 60bpm at vet gates before continuing. This is because in research horses with a rate of 60 or less inclusively 30 minutes after exercise, showed less dehydration and muscle stress than those with higher pulse rates. Horses who did not recover as quickly within this time developed severe dehydration and exhaustion when continuing, in some cases even developing colic [3,5]. Consequently, a swift cardiac recovery is a key factor to achieve endurance success [5].

Image from the horse.com

The second use of heart rate as an indicator of recovery is the heart rate drift, otherwise known as the steady increase in heart rate when the horse is becoming fatigued during exercise. Fitter horses will be able to maintain a similar heart beat for longer than those who are less fit [3]. Nevertheless, there are external factors that could affect accurate and representative heart rate readings such as fear, excitement and the presence of rider or handler [11]. This was proven in a study of a lone horse being ridden on the inside of a bigger track where other horses were being walked. Each time the lone horse came close to them and passed by, his heart rate was heightened. Here lies the strength of recording the horse’s heart rate over longer periods during which the horse can become accustomed to potential affecting stimulants and various situations over time can be compared [17]. By recording the heart rate during many exercise sessions over time, it is possible to detect an injury or illness earlier on should the horse’s heart rate remain heightened after an exercise session [5]. It could signal a problem such as lameness or respiratory difficulties which can then be addressed before further training [3].

Breathing rate

Just like in humans, how hard the horse is breathing is a good measurement of how their body is responding to their work. The average respiratory rate for the horse is 8-16 breaths a minute and should return to normal within 15- 20 minutes depending on the type of exercise (12,13). The quicker the breathing rate settles indicates the speed at which the horse is able to recover, thus their fitness level. You can monitor your horse’s breathing rate by watching the movement of the abdomen as it rises and falls.

Feel

Ultimately, training with our horses every day, we get to know them inside out, even when doing a variety of work. By gauging their response to our aids, most riders have refined the skill of assessing the horse’s fitness and recovery by eye and feel itself, especially as fitness and recovery can manifest in the horse’s appearance and overall health behaviour [4]. This emphasises the crucial requirement for the same individual to be involved in both the training and caring for the horse to develop an 'eye' for their fitness and is supported by one exercise researcher Hyyppä, who states "If one person trains a horse and another person looks after it, a wealth of equine information will fall by the wayside" [4].

Sleep

In terms of recovery, sleep is an essential element of an athlete's convalescence due to its physiological and psychological restorative effects from exercise [19,21]. This is because it helps restore the endocrine, immune and nervous system [24]. Disturbances in sleep pattern have been found to indicate overtraining and the quantity and quality of sleep tends to decline as training load increases [20]. As horses and REM sleep is particularly important for horses, as this is their only chance for the muscles to relax without bodyweight, it is a critical process of exercise recovery and recuperation [23]. To learn more about the horse’s natural sleep cycle, visit our earlier blog on sleep deprivation. Monitoring sleep can provide insights into the horse’s ability to cope with workload and help predict how well the horse is able to recover.

How long should a horse rest and recover for after a competition?

Knowing the importance of recovery and the impact it has on future work and overall health, how long should we allow for the horse to rest and recover after competition and exercise? And how could this be further impacted by travelling?

Research into the time needed for recovery for specific disciplines is relatively limited and most guidelines are extrapolated from human research. For horses competing in short strength related disciplines such as showjumping and dressage, a few light days after a competition or heavy session may be all that is required, just like for human sprinters [16]. Whereas for eventers or endurance horses, comparable to marathon and other long distance runners, they may need several weeks of lighter work and recovery time. Some human athletes believe ‘peak’ performances over marathon distances can only be achieve 2 or 3 times a year. This is not surprising when research shows runners completing more than 6 marathons a year were up to 2.5 times more likely to sustain a leg injury [16]. Could this be a similar statistic for horses in endurance sports?

There may also be discussion here for different factors affecting the speed of recovery such as age, gender or measures taken to help the horse recover. For instance, in humans some research found older adults required longer rest periods to fully recover than younger adults [14] and others found women more resistance to fatigue than men during specific exercises [25,26]. Could these differences be present between mares and geldings too? And could age and sex be related to a horse's individual speed of recovery?

Time taken to rest must also factor in the length and effect of travel. As transport can massively deplete a horse’s energy resources, it is important to factor in the distance and mode of travel into rest period following an event. Research shows reduced immunity, respiratory problems and interference with circadian rhythms are all detrimental consequences of road and air transport [27]. Learn more about the effect of transport here.  

How can Trackener help monitor recovery?

Trackener is a new 24/7 equine monitoring technology that allows you to track several factors of recovery simultaneously from an app on your phone. While your horse wears the Trackener device in a comfortable anti-rub bib in the stable, field or on the lorry, you can monitor sleep, activity and heart rate. By comparing these in the days leading up to and after training sessions and competitions, you can make sure that your horse is coping well with the workload and adapt your planning in the future to limit risks of health problems.

In addition, during exercise sessions, with the device sitting in a girth sleeve, see how much work you are doing (speed, duration, distance), watch how your horse responds in terms of heart rate and monitor how quickly your horse recovers with comparisons to resting heart rate. See an example in the screenshot of the app below.

If you want to get more information about our product, drop us a message here or check out our website.

We would love to hear how many of you currently monitor recovery and any interesting findings you may have found. Feel free to comment and let us know. Also don't forget to look out for Part 2 of the recovery blog to hear more about how you can help your horse recover and what the best practices are!

Written by Ruth Box BSc, EEBW @ruth_box6910 Email Ruth

References

[1] https://www.myvmc.com/lifestyles/exercise-recovery/

[2] https://www.sciencesupplements.co.uk/recovery

[3] https://ker.com/equinews/milne-feeding-horses-exercise-optimal-recovery/

[4] https://www.sciencedaily.com/releases/2007/11/071105144759.htm MTT Agrifood Research Finland. (2007, November 9). Rest For The Racehorse After Exercise. ScienceDaily. Retrieved September 11, 2018 from www.sciencedaily.com/releases/2007/11/071105144759.htm

 [5] https://equimed.com/health-centers/fitness-and-conditioning/articles/how-to-measure-your-horses-fitness-using-a-heart-monitor

[6] Valette-  Valette JP, Heiles PH, Wolter R. Multivariate analysis of exercise parameters measured during the training of thoroughbred racehorses. Pferdeheilkunde. 1996. Juli;(12):470–473.

[7] Munster - Munsters C, de Gooijer JW, van den Broek J, van Oldruitenborgh-Oosterbaan MMS. Heart rate, heart rate variability and behaviour of horses during air transport. Vet Rec. 2013. January 5;172(1):15 doi: 10.1136/vr.100952 [PubMed]

[8] Von Borrell Von Borell E, Langbein J, Després G, Hansen S, Leterrier C, Marchant-Forde J, et al. Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing stress and welfare in farm animals. Physiol Behav. 2007. October;92(3):293–316. [PubMed]

[9] Bitschnau C, Wiestner T, Trachsel DS, Auer JA, Weishaupt MA. Performance parameters and post exercise heart rate recovery in Warmblood sports horses of different performance levels. Equine Vet J Suppl. 2010. November;(38):17–22. doi: 10.1111/j.2042-3306.2010.00260.x [PubMed]

[10] Healthsmart healthsmartsite.com/horse-performance/lactic-acid-performance-limiter/

[11] Mukai, K., Takahashi, T., Eto, D., Ohmura, H., Tsubone, H., & HIRAGA, A. (2007). Heart rates and blood lactate response in Thoroughbred horses during a race. Journal of Equine Science, 18(4), 153-160.

[12] BHS file:///C:/Users/User/Downloads/5%20Normal%20TPR%20in%20adult%20horses%20(1).pdf

[13] Scott and Martin http://texashelp.tamu.edu/wp-content/uploads/2016/02/understanding-vital-life-signs-in-horses.pdf

[14] Fell, J., & Williams, A. D. (2008). The effect of aging on skeletal-muscle recovery from exercise: possible implications for aging athletes. Journal of Aging and Physical Activity, 16(1), 97-115.

[15] Meagher, J. (1985). Beating Muscle Injuries for Horses, I sted. United States of America, Hamilton Horse Associates.

[16] Van Middelkoop, M., Kolkman, J., Van Ochten, J., Bierma‐Zeinstra, S. M. A., & Koes, B. (2008). Prevalence and incidence of lower extremity injuries in male marathon runners. Scandinavian journal of medicine & science in sports, 18(2), 140-144.

[17] Clockit EQ http://www.clockiteq.com/interpretation-of-heart-rate-data/

[18] Vetfolio http://www.vetfolio.com/musculoskeletal/equine-exercise-physiology

[19] Pejovic S, Basta M, Vgontzas AN, Kritikou I, Shaffer ML, Tsaoussoglou M, Stiffler D, Stefanakis Z, Bixler EO, Chrousos GP. Am J Physiol Endocrinol Metab. 2013 Oct 1; 305(7):E890-6.

[20] Hausswirth C, Louis J, Aubry A, Bonnet G, Duffield R, LE Meur Y. Med Sci Sports Exerc. 2014; 46(5):1036-45.

[21] Chase JD, Roberson PA, Saunders MJ, Hargens TA, Womack CJ, Luden ND. Appl Physiol Nutr Metab. 2017 Sep; 42(9):909-915.

[22] De Graaf‐Roelfsema, E., Keizer, H. A., van Breda, E., Wijnberg, I. D., & van der Kolk, J. H. (2007). Hormonal responses to acute exercise, training and overtraining a review with emphasis on the horse. Veterinary Quarterly, 29(3), 82-101.

[23] Halson, S. L. (2014). Sleep in elite athletes and nutritional interventions to enhance sleep. Sports Medicine, 44(1), 13-23.

[24] Fullagar, H. H., Skorski, S., Duffield, R., Hammes, D., Coutts, A. J., & Meyer, T. (2015). Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise. Sports medicine, 45(2), 161-186.

[25] Albert, W. J., Wrigley, A. T., McLean, R. B., & Sleivert, G. G. (2006). Sex differences in the rate of fatigue development and recovery. Dynamic Medicine, 5(1), 2.

[26] Hunter, S. K. (2016). Sex differences in fatigability of dynamic contractions. Experimental physiology, 101(2), 250-255.

[27] Stewart, M., Foster, T. M., & Waas, J. R. (2003). The effects of air transport on the behaviour and heart rate of horses. Applied Animal Behaviour Science, 80(2), 143-160.

Disclaimer: Statements made in this blog are summarised from existing research not personal research. If you have concerns about your horse's recovery or are looking for veterinary advice, please contact your local vet. Information contained herein is for educational purposes only.