I titled this article "Heart Rate Training for the Rest of Us" because so many times we hear about top horses and top athletes going hard in interval training. We hear that interval training and "no pain, no gain" is the path to success in endurance athletics. I want to mention another path: the path of low heart rate training.
A very good introduction to low heart rate training is an article written by Ironman triathlete Mark Allen (www.duathlon.com/articles/1460). I have had success with my horse Frank using low heart rate training, and two of my riding partners, Max Merlich and Beth Bivens, seem to intuitively follow low heart rate training.
All three animals -- two horses and a mule, Frank, Niles, and Junior -- achieved Sandybaar awards in 2007: 10 consecutive completions of Pacific Northwest endurance rides without a pull. Two of the equines finished all five days and all 260 miles of the Owyhee five-day ride, and Frank received the five-day BC at the Owyhee ride.
My Arabian gelding Frank is endowed with incredible stamina and desire, but I think that low heart rate training is what has kept him running strong through 3,000 endurance miles.
The essence of low heart rate training is to condition the body to use fat for fuel. High speed, high heart rate activities use glycogen for fuel, but the human and equine bodies have limited glycogen reserves. Both humans and equines can turn in amazing bursts of speed for a short distance to escape a predator, or to be a predator.
Glycogen is a carbohydrate that the body burns fast and hot. However, when the glycogen is gone, the athlete, horse or human, "hits the wall" and metabolic problems follow. Glycogen alone is not likely to get your horse through 50 miles. Nearly all of us, humans and horses, have ample fat reserves that we can use to power us through the endurance miles.
Mark Allen and others recommend that humans do all of their training at a heart rate where the body uses fat for fuel. The classic human low heart rate formula is: Maximum Training Heart Rate = 180 minus your age (with a few adjustments for fitness). Please note that the low heart rate formula is considerably different than the traditional heart rate calculation. The low heart rate formula seems to be inaccurate for young athletes and for senior athletes.
Still, the formula works for most people between 25 and 60 years of age.
A 40-year-old human would have a maximum target heart rate of 140 beats per minute using the above formula, and low heart rate training would require that all physical training be conducted at a heart rate lower than 140 beats per minute. I use 140 at the upper limit for my horse, and I generally try to keep all of the training and all of the endurance riding at a heart rate lower than 130. Uphill and down, I try to keep Frank's heart rate below 130.
The equine maximum heart rate is estimated to be around 240 beats per minute for 2-year-old Thoroughbreds and probably slightly less for Arabians. A conditioned 15-year-old Arabian may have a maximum heart rate around 200 beats per minute. No one recommends running an endurance horse at a heart rate of 240 beats per minute. Short periods of 180 beats per minute may be repeatable for endurance horses, but my recommendation is to condition and ride at far lower heart rates.
No one that I know has proposed a specific low heart rate formula for horses and my training range below 130 beats per minute is based more on intuition than on science. I arrived at the number by observing how my body performs when I am in the proper range and seeking the same level of effort for the horse. The human formula is based on age and I imagine that the equine formula would also reflect age. Some guidelines might be:
-- Reasonably fit horses 7 to 14 years old: Conditioning range under 140 bpm
-- Reasonably fit horses 15 to 22 years old:Conditioning range under 130 bpm.
I would subtract 10 or more beats per minute for horses that are just starting their conditioning programs.
Many of the people who use heart rate monitors seem to be focused on heart rates above 150 beats per minute and some push to heart rates as high as 180 beats per minute. I have heard talks about endurance conditioning and the speakers have recommended that the horse run up a long hill at a sustained heart rate above 150 beats per minute. Low heart rate training would have you take your horse up the hill at whatever pace is necessary to maintain the heart rate under 140 or 130 beats per minute, even if that pace is a walk.
I too have tried the high heart rate training with myself and with my horse. Frank had some awesome runs, but he was plagued by low body weight and intermittent lameness during his high heart rate training days. Eventually, I had to give him some extended time off and gently ease him back into endurance. During the time off, I switched to low intensity training. Now my main problem is how to hold him back for five days and 260 miles.
The winter off-season is an excellent time to begin low heart rate training. Many of us reduce the training intensity in the winter anyway. You can extend the distances but keep the heart rate low on through your spring conditioning and into the summer endurance season.
If you haven't been conditioning your horse at a low heart rate, what you may find is that the low heart rate will result in a pace that seems incredibly slow and you may think that you are not working your horse hard enough. Low heart rate training requires patience and a focus on the long-range goals. Eventually, your horse will develop speed, but at a much lower heart rate that is sustainable over many miles and days.
The slow pace has given rise to comments among my training partners as we move along the trail in a relaxed manner: "Here we are training at our top-ten pace, again." Still, Frank has the speed and he demonstrated that speed to finish Tevis in 2006.
The point is to do all conditioning below the maximum target heart rate. With time, you will likely find that your horse's speed will increase at the low heart rates and eventually your horse will be running fast with a low heart rate. Your horse will become a fat-burning machine! The complement to using fat for energy, and the complement for any endurance conditioning, is that fatness is a vital component of fitness and a moderate level of body fat is necessary for consistent endurance performance and necessary to reduce the likelihood of metabolic problems.
Mark Allen mentions that you will eventually find a fitness plateau using low heart rate training. He notes that is the time to mix in a small amount of interval training if you want to move beyond the plateau. The idea is to do no more than 15 to 30 minutes of total interval training in a workout session, perhaps one time per week.
But, it is critically important to build the aerobic base using low heart rate training before adding the interval training. I think limited interval training may be beneficial for horses after they reach aerobic fitness, but the key word is limited. Perhaps the right approach is following Allen's recommendation of 15 to 30 minutes of total interval training during one session per week until your horse reaches another fitness plateau. Then it is time to return to low heart rate training to strengthen the base aerobic capacity again. You will also want to eliminate the interval training and follow low heart rate training when your horse is tapering for a big run.
However, after low heart rate training you may be satisfied with your horse's fitness plateau, the metabolic condition of your horse, and your horse's performance at endurance rides. If you are satisfied, then there is no need to add any interval training. No one will dispute that interval training is hard on the joints. You can maintain your horse's fitness level with low heart rate training. All you need to do is continue your conditioning program and monitor your horse's heart rate.
During endurance rides the point is to keep the heart rate below the top values in the range just like when conditioning -- under 140 beats per minute and often even lower. One way to think about the rides is that horses and humans have a limited "daily budget" of high heart rate events before developing metabolic problems. Some rides like Tevis will require periods where the heart rate is above the target zone for almost any horse. It is important to be frugal with those high heart rate trail sections and important to be mindful of the "daily budget."
Dr. Phil Maffetone is credited as the one who first promoted low heart rate training. Athletes like Mark Allen and Lance Armstrong applied the methods to their conditioning programs and achieved elite status. Allen and Armstrong have elite genetics too. Few of us, and few of our horses, have those elite genetics but I think that low heart rate training will allow all of us to run closer to our potential with fewer injuries.
If your goal is Pan American or FEI competition, you may want to continue the traditional training regime: intense interval training is the standard conditioning program. However, you may want to consider low heart rate training too. Low heart rate training built the foundation to achieve world-class results for athletes like Allen and Armstrong, and both endured on the top step of the podium for many years.
