With information about physical fitness virtually everywhere, no one needs to be told that measuring heart rate during exercise is the accurate way to assess work load. Most of us simply gauge our horse’s sweat level and breathing rate. While this works, it won’t give you the solid information you need to condition methodically. Monitoring heart rate is the best way to go, and it’s not difficult to do.
Basically, a horse’s heart rate increases linearly with speed. When working at a constant speed, heart rate increases when other factors influence the difficulty of the work: excitement, pain, heart/lung disease, deep footing, hill work, poor riding and overheating.
Unfit horses have higher heart rates than fit horses when performing exercise of the same degree of difficulty. By knowing how hard the horse’s heart is working you can get a good idea of how much the horse is being stressed overall.
Establishing Normal Baselines
There are no hard-and-fast rules for equating heart rate with a specific activity beyond the fact that any horse’s maximum heart rate will be around 220 beats per minute. At rest, the normal range for heart rates is mid 20s to mid 40s with fitter and quieter individuals tending to have the lower rates. As you progress from a slow trot to a working trot, heart rate will climb from somewhere in the 60s to as high as about 150. Again, there is a tremendous variation between horses, so it is important to determine “normal” for your individual and his level of fitness.
At the start of a conditioning program, your goal should be to avoid overstressing the horse. For some horses, just climbing a hill at a walk will cause significant stress while another may be able to go up fairly effortlessly at a trot.
To establish a safe starting heart rate for your horse, look beyond the heart-rate monitor reading:
Is the horse blowing'
Is there excessive sweating'
Is his gait becoming less steady'
Is he resisting going forward'
The sum of these observations, plus the heart rate, will let you know if the horse is being pushed. The “average” horse may tolerate a heart rate of 140 or so before showing fatigue, but if the horse is becoming distressed at 120, let 110 be your ceiling/target heart rate to begin with in your conditioning program.
As a general precaution, stay below 140 to 160 during the early conditioning phases of long slow work (LSW). For most horses, especially unfit horses, this represents the anaerobic threshold — the point at which the horse must rely on lactate-producing energy pathways. Since this type of exercise is less efficient, fatigue can occur quickly and injuries go hand-and-hand with fatigue.
In the LSW early stages of conditioning, you must be careful not to overstress the bones, ligaments, joints and tendons. Horses are inherently cardiovascularly efficient — much more natural athletes than are humans. The circulatory system will become conditioned more quickly than the muscles and as much as four to six times faster than the skeleton, joints and ligaments/tendons. You must protect these structures by not allowing the horse to work above your target heart rate and never above 140 to 160 (higher value for horses that had lower heart-rate responses to begin with).
Using A Monitor
A heart-rate monitor tells you how hard you are working your horse but doesn’t answer the questions of how long or how far to go. Most conditioning “recipes” are written for serious event, endurance or race riders and speak in terms of distances and speeds. However, when your routine includes a considerable amount of ring work these tips aren’t too helpful for most horses.
Warm-up by walking and slow jogging (pulse under 100) for 15 to 20 minutes. A half-hour of trotting (the gait you should use for almost all of the LSW phase) amounts to between three to four miles. Heart rates at this speed will vary but usually fall between 110 to 140. When starting out with a young horse or a healthy adult, you should be able to safely trot for 20 to 30 minutes, but if the horse shows any signs of unusual distress (heart rate climbing instead of staying steady, breathing rate rapidly climbing), stop before this. (As the horse gets fitter, you can increase the time worked before stopping or increase the number of 30-minute “sets” you do or progress to a faster trot or a canter/lope if it is tolerated inside your target heart rate.)
After the trotting, slow the horse to a walk and measure the two-minute, five-minute and 10-minute pulse rates. A rapid drop to below 90 indicates you did not overstress the horse. If the drop was not that rapid, walk for the full 10 minutes and get an accurate 10-minute recovery pulse rate. Recovery heart rates are just as important as the rate during the work, and heart-rate monitors are almost indispensable for monitoring them.
As the horse gets fitter, the rate at which his heart rate drops while walking after exercise stops is an excellent indicator of how well he tolerates this level of work. As above, measure heart rate at two-, five-, 10- and 15-minutes after work stops. If your horse’s heart rate recovers into the 60s or lower at the 10-minute mark, you aren’t doing enough work to get much conditioning effect. Increase your target rate by 5 to 10 bpm and recheck.
When doing slow, aerobic work, the heart rate should fall to the low 70s (or in the range of double the resting heart rate or half the heart rate during work) within 10 minutes. If it doesn’t, you are working either too long or too hard and have your target heart rate set too high. Give the horse a day or two off and repeat the test with your target heart rate about 10 bpm lower.
You may see some variations on heart-rate recovery monitoring, e.g. heart rate down to 90 to 100 in two to five minutes, especially with reference to interval training where it is important to make sure the horse is recovering but not fully recovered before going on. These are fine under those circumstances but may work better with early speed work training programs. For safety and aerobic conditioning, 10-minute goals are more flexible.
As fitness improves, heart rates will plummet toward resting values within seconds of stopping work. This is an important cue that it is time to step up the intensity of your workouts.
Beyond Basic Conditioning
Every horse should have the benefit of anywhere from 200 miles (adult, after lay-off) to 400 miles (young or old horse) of LSW before entering a conditioning program designed for a specific activity. This translates to a minimum of 100 hours in the saddle. Beyond this point, exercise programs should match the demands of your own sport.
Endurance riders will want to concentrate on building aerobic capacity, increasing the length rather than the speed of their exercise sessions, building up to heart rates in the range of 160. Most will also do a little work in the 180 range to hopefully bring the horse’s aerobic capacity up to its fullest capacity. Fine-tuning involves experimenting with different trotting speeds to find the range where the horse is most efficient (every horse has one) then covering most miles at that speed to build the horse’s metabolic efficiency.
Event riders need both aerobic and anaerobic (speed) conditioning. Most of the work is done under aerobic conditions but upper-level cross-country work and even some stadium courses do make some demands on the anaerobic system.
The event rider will thus combine days of five- to 10-mile cross-country works to build stamina with interval sessions targeting heart rates of 180 or so, as well as specific schooling in jumping and dressage. The combined-training event rider (like the point-to-point or hunter-trial rider) will also want to work the horse over specific distances required with the goal of developing pace and improving the horse’s ability to handle the needed speed and distance.
Any horse performing against the clock needs a sensible, safe and effective training program to develop speed. Interval training, using heart-rate monitors to stay within speeds the horse is conditioned to tolerate, is the most efficient method.
Speed interval training on the flat usually uses either 3 x 1 (three sets of one mile each) or 4 by ?? (four sets of ?? mile each) intervals. These include a 10-second difference in speed between each (dropping with each set) and a 10-minute rest (slow jogging) between each set.
A horse that does not recover to a heart rate of 90 (early speed work) to 110 (higher speeds) within two minutes is finished for the day and will usually be dropped back to the speeds he tolerated before trying to drop him further. Jumpers, steeplechasers, barrel racers, etc. will eventually move from flat speed work to specific competition conditions for some of the workouts. One to two such serious speed works per week is the maximum suggested.
For details on conditioning for sports requiring a high degree of fitness, we suggest The Fit Horse II by Tom Ivers, Go The Distance by Nancy Loving DVM or Conditioning The Sport Horse by Hilary Clayton DVM, Ph.D. At tack and book stores.
Also With This Article
Click here to view "Fitness For Every Discipline."
Click here to view "Rating The Monitors: EasyBeat and V-Max."
Click here to view "Applying Heart-Rate Monitors."
Click here to view "What Heart-Rate Monitors Won’t Tell You."
Click here to view "Don’t Want A Heart-Rate Monitor'"
Click here to view "Speed Play."