RESONANT RIDING

Resonant Riding
A Tool for Winning
Be ONE With Your Horse, ride in resonance.
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To improve performance the rider should be in charge, you pick the speed and you pick the gait. Follow the data in figure 1 below and you can save 15% or more energy for the same distance traveled.

The quintessence, of endurance riding is the thrill of being ONE with your horse. It is like a slam dunk, the jelly center of a donut, the high five, the meaning of it all. This is why we are out there, to experience this feeling of being in tune, “in resonance” with our horse. We develop “en rapport”, a friendship, a bond with our horse. It is hard to put into word but you all know what I mean or you would not be out there. As we ride, we notice sometimes we seem to be in sync with the horse and sometimes we are not. How can we achieve this state of Nirvana? When in doubt always look to physics (1). The laws of physics apply to all physical things and serve us as guide posts to get the most out of any mechanical system. A review of these laws will give us a sense of how a resonant mechanical system operates. Most good horsemen and all horses already know all these things intuitively but do not always put them to best use. By dragging out old high school physics equations we can better understand the rules for this oneness with the horse. Regardless of where you ride in a race you can use resonant pacing to advantage. This article will introduce the resonant riding concept and present examples of it’s use.

A horse, a saddle, and a rider, are all part of a spring – mass system. You will recall that the frequency of a resonant mechanical system in simple harmonic motion is given by f = 1/T, where T is the period and that T is equal to the square root of the mass divided by the spring constant times 2 pi. As a horse or human runs all the organs bounce around at different speeds. At resonance they all move together and assist breathing by helping the diaphragm move in cadence with the body motion. In other words for each gait there is an optimum speed. ( resonance). You can do this experiment at home. Take a simple spring and attach a weight and observe it bouncing up and down as illustrated in the sketch below.

Give the weight (W) a downward push, inputting energy. You will notice that the weight starts bouncing up and down, up and down at a precise frequency. This is simple harmonic motion of a spring – mass system in resonance. To demonstrate the amount of energy it takes to drive this system, take hold of the weight and ride up and down with it inputting only as much energy as is needed to keep it going and that is very very little. Now still holding the weight start to increase the speed with the same amplitude, distance traveled. By increasing the speed you must drive the system at a higher frequency and this as you will notice takes more energy, a lot more if you go faster. Now this what you would expect, if you want to go faster you are going to have to put out more energy, but you are surprised as to how much more it takes to operate at a faster speed. Still holding the weight, go back to resonance, this is easy and you are glad to be there as it is obvious that this is where the system likes to operate. NOW HERE IS THE KERNEL OF THIS WHOLE CONCEPT. Still holding the weight going up and down, GO SLOWER, you will find that it take more a lot more energy to drive the system slower than at resonance. This is my message. Ride at resonance, this is where you and the horse are one, using the least energy at the fastest speed. The spring-mass system is a highly tuned system , while the horse and rider is a far more complex with more damping to minimize the effect of the resonance but the concept still applies. There should be a resonance corresponding to each gait. Humans have two gaits and horses have three.

A simple experiment you can try, is to run on a tread mill at the gym with a heart rate monitor on. Start out walking slowly and plot the heart rate as you speed up. You will notice that at a speed which coincidentally is the one you are most comfortable at, the heart rate will level off or even drop a little while you are increasing the speed. Then as you increase the speed even more the heart rate will again start climbing. This effect has been studied by a number of researchers (2 3). At the run this resonant point is not as noticeable but again it will be where you feel the best. Actually the heart rate is a poor indicator of energy consumption but it will serve as a simple experiment available to us all. (with heart rate monitors) The best indication for energy expended is the oxygen consumed. This is difficult without elaborate laboratory equipment.

Animals running in the wild tend to select a gait that minimizes their oxygen consumption (4). That is the speed which uses the least energy. However if left to choose, they change gaits at speeds where the oxygen uptake is nearly the same at each gait. This is not the most efficient point of transfer. So it is not always prudent to allow the horse to choose the gait. Hoyt and Taylor have measured the oxygen consumed by horses, at the walk, at the trot and at the gallop up to 7 meters per sec (15.75 mi/hr { miles per hour}) as a function of speed (5). I have taken their data and presented it in Figure 1 below. This figure says it all. It shows just when to transfer from the walk to trot and when to transfer from the trot to the gallop. Now using Figure 1 below, we can see that we want to walk at point “A” which is about 3 mi/hr. For the trot we want to be going at the speed corresponding to point “B” which is 7 1/2 mi/hr. For the gallop we want to be at point “C” which is around 12 to 16 mi/hr. At the gallop the curve flattens out and the resonance point is not as distinct. From this graph we can now determine that we want to be walking at 3 mi/hr, trotting at 7.5 mi/hr and galloping at 12 to 16 mi/hr. You do not want to be walking or trotting at speeds between 3 and 7.5 mi/hr. You do not want to be trotting or galloping at speeds between 7.5 and 12 mi/hr. You want to travel at resonance. To adjust your speed switch gaits. I often hear someone brag how fast their horse can trot. The important thing is how efficiently you use your horse through the ride. This is one of the main reasons that I keep saying ride alone, ride your pace. If you are riding with another horse, one of you may be off resonance and in the long run you will use more energy to get the same distance in the same time.

The above is only theoretical. This not the real world. The resonance speeds vary form horse to horse. The measurements were taken with no weight on the horse and these were small horses. Of course, when you swing into the saddle the numbers are going to be slower. So you must determine the speeds for yourself for each of your horses, if you are lucky enough to have more than one. The point here is that at each gait there is an efficient speed to travel at. Do not go faster and slower in that gait, switch gaits.

Insert Figure 1

In later work ,Farley and Taylor measured the voluntary speeds that horses with loads change gaits, and they found that horses running on tread mills did not try to minimize oxygen consumption but tried to reduce the forces in the muscles and tendons (6). They found that as the horse switched from the trot to the gallop the stress in the legs were reduced 14%. This is a lot of force reduction and maybe reason enough to ride at the gallop. There have been a number of good studies made of the stresses in the legs of horses at the transition from trot to gallop (7 8).

How can we determine these speeds for our own horse? Each horse has different conformation. The saddles are different weights, and the riders are of different conformations. We could ask the one who knows best, the horse. In other words, “listen to your horse” and if we are sensitive to their response we learn a lot. We can also do a similar heart rate experiment with the horse as outlined above for the runner. You could mark off a known distance and determine the pace or have a helper ride in a car or motor bike and measure the speed while watching your heart rate monitor. But just knowing of the existence of resonance at each gait will help zero in on the optimum speed for the horse, saddle and rider at each gait. Now if the weight is changed like a lighter saddle or getting off and running, things will change. As the horse tires the spring constant will vary. So this is not a fixed situation and must be continually monitored. Be in sync with your horse and you will sense when this happens.

Resonance: WHO CARES?

Just to know that there is a speed that uses less energy at each gait is an important weapon for the competitor or if you just want to finish this is the best pace to ride at. Any faster and you will be operating less efficiently BUT, any slower and you will also be more inefficient at each gait.

You should always ride at resonance approaching the vet check. This is the best way to get your pulse down a mile or two out.

It is also beneficial to vary the pace to engage different muscle groups when possible. Switch from a trot to a gallop and back. You have probably noticed that your horse already does this himself, so listen to him. Sometimes he will change gaits and maintain the same speed. You will need to adjust the speed to resonance at the new gait or you will be inefficient. It is sure easy to tell everyone how to ride theoretically but an entirely different matter out there on the trail. But if you keep this idea in mind you can better ride, a higher vet score and pass more horses at the end.

At the last ride some riders who did not understand the physics of all this left a call for help;

“SEND WHISKEY AND FRESH HORSES”

1. My children tell me that I have only two solutions for everything, one is physics and two is running.
2. Minetti, A. E., et al. Med. Sci. Sports and Exerc., Vol. 27, No. 8 pp. 1194-1202, (1995)
3. McMahon, T. A., J. exp. Biol. Vol.115, pp. 263-282 (1985)
4. I would like to thank Karen Steenhof for bringing several valuable references to my attention.
5. Hoyt, D. F., Taylor, C. R., Nature, Vol. 292, 16 July , pp. 239-240 (1981)
6. Farley, C. T., Taylor, C. R., Science, Vol. 253, 19 July, pp. 306-308, (1991)
7. Biewener, A. A., Taylor, C. R., J. exp. Biol. 123, pp. 383-400, (1986)
8. Rubin, C. T., Lanyon, L. E., J. exp. Biol. 101, pp. 187-211, (1982)