In which Endurance 101 teaches a skill that isn't a dance
Endurance 101 : The “Ridgeway Trot” (CRI):
"The Ridgeway Trot"...sorta sounds like a dance step, doesn’t it?
Bow to your partner, bow to your corner, do-si-do and Ridgeway trot!
Though the foxtrot and the turkey trot, really are dance steps, the “Ridgeway trot” isn't. Also known as the Cardiac Recovery Index, (or CRI), the Ridgeway trot is a tool that vets at an endurance ride use to judge a horse’s progressive recovery from exercise. The technique was originally advocated by AERC Hall of Fame endurance rider and veterinarian Kerry Ridgeway, DVM, and the name “Ridgeway trot” got stuck on it.
Some vets will use a CRI at every ride, at every vetcheck, on every horse. Others will use the CRI only when they suspect a problem and want more information about the horse’s metabolic health. The CRI is always part of a Best Condition exam, so that vets can compare the level of fatigue of the horses being shown for BC.
For the rider, the CRI isn’t much more complicated than a normal trot-out. The examining vet, however, takes a few extra steps during the process to gather data. Here’s how it works:
· The vet takes the pulse of the horse at the beginning of the examination, and then starts a stopwatch.
· As soon as the pulse is recorded, the handler takes the horse out on a normal trot-out, approximately 125 feet out and 125 feet back (45 strides or so, each direction).
· When sixty seconds have passed from the time of the first pulse-check, the vet measures the heart rate of the horse again, and compares the two measurements.
Ideally, the two numbers are the same. If the pulse of the horse at each point in the check was 60, the CRI score is recorded as 60/60.
In the case of a very fresh and/or very fit horse, the second number may be lower than the first. If the pulse of the horse was 60 beats per minute before the trot-out, and 56 beats per minute after the trot-out, the CRI score is recorded as 60/56.
If the pulse has increased after the trot-out, there is cause for concern. While a 4-beat increase (from 60 bpm to 64 bpm, for example) isn’t alarming, an 8-beat or higher increase is fair warning that the horse might be too fatigued to continue the ride in good health.
As a rider, you want the vet to gather accurate information about your horse’s level of fitness during a CRI exam. For most horses, that means that your trot-out should be performed at a medium-slow jog, rather than a brisk run. This pace keeps him from overheating, and allows his heart rate to drop when you return to have it checked the second time.
You won’t have an opportunity to slosh water on your horse between the two pulse-checks, so you want to avoid letting him “build up steam” that will make his heart pump fast. It is permitted to verbally and physically soothe your horse by stroking his neck and asking him to lower his head. I like to yawn at my horse after we return to the vet. This physical motion relaxes me, and indicates to the horse the message that nothing interesting is happening here, so stand still and relax for a bit. Even fake yawning works—your body can’t tell the difference between a real yawn and a fake yawn--the process will slow your breathing and relax your muscles, and this cues your horse to relax with you.
(Do you yawn just reading the word “yawn”? I do!)
You also want to avoid stressing your horse emotionally between the two pulse-checks. If your horse’s best buddy has been beside you all day during the event, and the buddy leaves to go to the water tank in the middle of your CRI exam, your horse may have an emotional melt-down—and his heartrate will skyrocket. Make a deal with your riding partner in advance to stick close together when the horses are being examined. Vets understand about “buddy horses”; as long as the “buddy” is standing quietly and not crowding anybody or making a fuss, nobody will mind having the two horses stand side-by-side while pulses are taken.
If a vet is concerned about the metabolic status of a horse, s/he may ask to repeat the CRI at intervals at least 10 minutes apart. The numbers on the CRI should improve as the horse rests. For example, a horse with a CRI of 60/64 ten minutes after arriving at the vet check can be expected to show a better score (52/56, for example) after 10 or 15 additional minutes of rest.
If the horse has met the “fit to continue” parameters, but his CRI score does not improve dramatically, , he is not automatically pulled from competition; however, the rider should recognize that the horse may need more recovery time in the vetcheck to eat, drink, and rest. It’s okay to stay longer than the required hold time at a vet check!
It’s also okay to perform your own CRI exam on your horse before leaving a vetcheck, especially if you plan your ride strategy for the next leg of the journey based on his scores: a horse whose CRI after 30 minutes or more is 42/42 is ready to go out and trot down the trail at his normal speed. A horse whose CRI after the same period is 50/54 might be able to continue, but will probably benefit from a longer lunch break and a slower pace when he returns to the trail.
Practice the CRI at home at the end of your training sessions. This will teach your horse the process and also give you familiarity with his “normal” recovery numbers and times.
· Before you begin, stride out 45 steps and drop a rock or a jacket as a landmark.
· Measure your horse’s heart rate using a stethoscope.
· Start your stopwatch (my phone has a “stopwatch” feature that is handy for this).
· Trot out to your landmark and back. Practice the slow-steady jog that you will need at vetchecks.
· After 60 seconds have elapsed, check your horse’s heart rate again.
That’s the Ridgeway trot!