That is correct Sandy, they use it to measure heart rates and recovery times on distances and training. The sensor is waterproof wireless and connected on the wrist watch so the guy who rides it can check it anytime he likes. It is usually straped around the belly or the chest of the horse.
What kind of competition is the horse training for? Way back when, I did some conditioning with Penny for competitive trail riding, but I never got so serious about it that I'd invest in a heart rate monitor. Competitive trail riding is distance riding, but it differs from endurance riding because it's not a race. The fastest horse does not necessarily win. Instead, a vet checks the horses over before the ride, things like soundness and heart rate and hydration, and then everyone rides the same distance over the same route. There is a time frame the ride has to be completed in -- no sooner than a certain time, no longer than another time. The horses don't all start at the same time, the start is staggered, and the time each horse left is written down. Then when the horses return, the time is written down to be sure that no one was too slow or too fast. And then a vet checks the horse over after the ride, looking for things like a too-slow recovery rate, lameness, back soreness from the saddle, etc. The results of this exam are compared to the results of the exam before the horse left, and the horse with the smallest changes wins. I liked that concept because it tests the fitness of the horse more than the speed. Getting a horse really fit is a fine art, I learned. I had a friend who turned me on to it, and she was very experienced at competitive trail riding, so she mentored me and gave me suggestions and advice, and we rode our horses together sometimes to hone their fitness. I went to a competitive trail riding clinic, where we learned more about it, and the culmination of the clinic was a 15-mile ride. Whew! I had been conditioning using 5-mile rides, and this was way more tiring, plus Penny wasn't used to going in a large herd like that, each person going at their own pace, and she wanted to keep up with the fastest horses in front, which would mean we'd finish too soon. After that, I decided the 25-mile competitions would be too much for us. I liked conditioning Penny (and myself), but I didn't like the pressure of a competition. So that's my story about this kind of riding and how I learned of heart rate monitors. Most people couldn't afford them and just used a stethoscope to see how quickly a horse's heart rate returned to normal after a conditioning ride.
