The time it takes for a horse’s heart rate to recover is a great indicator of fitness. Typically, after moderate work, your horse’s heart rate should return to 100 bpm within two minutes and should be below 60 bpm ten minutes after exercise has ceased.
All riders can use the heart rate recovery time as an indicator of fitness, but it is especially important for endurance horses.
The nature of an endurance competition is such that as a horse comes off a loop and into the vet gate, it’s riding time does not stop until the horse’s heart rate has dropped below 64bpm, at which point it is checked by the vet.
If two horses come off the loop together and one horse takes one minute to get to 64bpm and the second horse takes five minutes, the first horse will have a four minute lead on the second.
Much work has been done looking at the recovery rates of horses, and how the heart rate at these checks indicate the fitness and likeliness of completing the competition.
One study showed that endurance horses who took longer than 11- 13 minutes to recover to 64bpm were associated with a higher risk of being eliminated by the vet due to metabolic concerns. It also showed, that if they did pass that examination and went out onto another loop they had a 70% chance of being eliminated at the next vet check [i].
Another study looking into the recovery check of endurance horses gave further insight as to how heart rate is an indicator of fitness and likelihood to complete the event [ii]. Horses had had a 40 minute rest hold, and were then re-checked by the vet before going back out onto the track. The heart rate was taken, the horse was trotted and the heart rate was taken again – known as the cardiac recovery index (CRI). If the first heart rate was over 60bpm they were less likely to finish the competition. If the first heart rate was over 50bpm and the second heart rate was 54 or more bpm they were less likely to finish the competition. If the first heart rate was below 50bpm they were more likely to finish the competition.
The rationale behind the CRI is that after brief exercise (the trot up) fit endurance athletes quickly recover whereas tired or sick horses have rates that remain higher for longer periods of time. A positive CRI is considered as an indicator of fatigue, pain or toxaemia [iii].
This highlights how the recovery of a horse is a great signpost for its fitness. Monitoring recovery times in training is important, and gives you valuable information as to whether the session was too intense for your horse, or if your horse coped well with the work that was undertaken.
[i] Nagy et al., 2010; Younes et al., 2015; Bennet and Parkin, 2018
[ii] Use of the recovery check in long-distance endurance ridesC. ROBERT*, A. BENAMOU-SMITH†and J.-L. LECLERC EQUINE EXERCISE PHYSIOLOGY 6Equine vet. J., Suppl. 34(2002) 106-111
[iii] Slusher, S.H. and Mackay-Smith, M.P. (1991) Endurance ride veterinary control.Proc. Am. Ass. equine Practnrs. 37, 793-805.
Fiona Farmer BVSc MRCVS
If you have any questions or worries about your horse’s heart rate, speak to your vet.