Conditioning Young Horses

Research shows that appropriate amounts of exercise during the first three years of a horse’s life can benefit the musculoskeletal system
Before your equine athlete begins full-scale training, he can benefit greatly from preparatory physical conditioning. Yes, it’s true that he’s still growing, that sensitive structures such as his joints and tendons are still developing, and that, generally speaking, he’s immature. But veterinary researchers agree: A fair amount of exercise will do him a significant amount of good, not only now but for his entire life. So, it’s important to get your youngster out of the stall and into shape.
Muscles, Tendons, and Bones
The first three years of a horse’s life—particularly the first two—are a time of great change and development in his locomotor system, particularly the muscles, tendons, and bones (including joints). These structures are the ones you keep in mind most as your prospect matures.
Researchers note that growing muscles adapt to the discipline for which the horse is preparing. That’s especially true for how these structures metabolize energy, meaning how they store oxygen and use fat as an energy source. So developing equine muscles properly via exercise is primordial in preparing the young athlete.
Tendons accumulate collagen during growth, which plays a role in their stretchiness and resistance, so safeguarding these structures is critical as well.
As bones grow, they not only increase in length and width but also in density. The mix of minerals in the bones changes, and the bones’ inner and outer membranes and outer shells thicken. All these parameters affect bone strength, so, once again, promoting optimal bone growth is essential.
While providing a young horse with suitable nourishment plays a major role in the development of each of these structures, equally important in successfully “growing” an equine athlete is the kind of exercise he receives during these critical first three years.
Preparing for their Future
Results of numerous studies on equine exercise over the past decade show a common trend: Appropriate levels of exercise in young horses have no negative effects on their musculoskeletal system. Exercise might even be beneficial for their futures, as it seems to build slightly stronger bone and more resistant tendon tissue.
“This goes against what people have often thought,” says Roger Smith, MA, VetMB, PhD, DEO, Dipl. ECVS, MRCVS, professor of Equine Orthopaedics at the Royal Veterinary College, in the United Kingdom. “People worry about exercising and racing 2-year-olds and are afraid it could be damaging.”
But now researchers recognize these early months and years offer certain windows of opportunity—when exercise can have a lasting, positive effect on these tissues while they are what scientists call “responsive.”
“Different tissues ‘respond’ at different times,” says Smith. “Tendons tend to be responsive early on in life, joints and bones a little bit later. Certainly we know that bones are especially responsive when (horses) start training as yearlings and 2-year-olds.”
Hilary M. Clayton, BVMS, PhD, Dipl. ACVSMR, MRCVS, professor and McPhail Dressage Chair Emerita at Michigan State University and president of Sport Horse Science, in Mason, Michigan, agrees that horses benefit from exercise as youngsters. She says it gets the horse’s muscles—including his heart and lungs—eady for a lifetime of athletic performance, adding that “conditioning prepares all the body systems to produce a maximal performance and also, very importantly, to withstand that maximal performance.”
Getting a Head Start
How young is too young for training and conditioning? According to researchers, conditioning can never start too early. “The introduction of low-level exercise, as early on as possible, even as a foal, appears to be protective,” says Smith. “Most of the epidemiological data indicates that animals that start their careers (this) early are more resistant to tendon injuries, at least.”
Physical conditioning on the ground, without training under saddle, can and probably should begin at birth, notes Johanna Lepeule, MS, PhD, research fellow in the department of environmental health at Harvard University, in Boston, Massachusetts. Lepeule studied bone growth and osteochondrosis in young foals while working on her veterinary epidemiology doctorate in France. Osteochondrosis in horses is a disease that occurs when young bone tissue does not mature correctly. Her research showed that foals (particularly younger than 2 months) exercised freely in a moderately sized pasture every day had developed significantly fewer osteochondral lesions by 6 months, based on radiograph examination, than foals kept in stalls.
“They have to get outside and moving,” she says, to prevent these problems.
The Right Program
Conditioning young horses requires careful planning. When building a program keep in mind the difference between conditioning and training. Clayton explains that conditioning is physiologic preparation, whereas training is teaching technical skills. You’ll want to work on training too, but that’s a separate issue. First focus on your initial goals of improving physical fitness.
“In the early stages, conditioning is fairly generic (for all disciplines),” Clayton says. “Work on building aerobic fitness and strengthening the tissues. Build up the aerobic component of work in the early stages while allowing time for the musculoskeletal tissues to respond.”
Once your horse is ready to go under saddle, trainers should focus on “slow, easy work” that will allow the horse to get used to having a rider’s weight on his back and to round his back under that weight (by strengthening the thoracic and pectoral muscles),” says Clayton.
Later, the rider/trainer can adapt conditioning to match the discipline. “The exercises will be more similar to what will be required in competition,” she says.
While we’re planning for ultimate physical fitness for our athletes, Clayton says we also need to keep in mind their mental fitness. An unhappy horse isn’t going to perform well, regardless of his physical condition.
“Souring,” which means the horse seems to hate working, can happen in youngsters, but it’s fairly rare and would require extensive regular exercise, according to Smith. “At a very high level of intense exercise you could start to see a psychological aspect, like you would in young human athletes (who have pursued the sport with too much intensity),” says Smith. “But the level of exercise we’re talking about in young equine stock is much lower than the level needed (to cause the type of effect in horses that we see) in human athletes.”
As the field of equitation science expands, we can also take advantage of an improved understanding of equine stress when working with young horses. Equestrian scientist Witold Kedzierski, PhD, from the department of animal biochemistry and physiology at the University of Life Sciences in Lublin, Poland, has been focusing on this very issue.
Kedzierski recently determined that 3-year-olds learning to work under saddle displayed lower physiological stress levels (in particular, lower heart rates) when handlers trained and conditioned them using “natural” methods (working with horses individually in a round pen, starting them with ground work, schooling them to avoid pressure, and helping them get used to unfamiliar objects) versus conventional methods (walking horses on an automated walker, longeing, etc.). “This was especially true for colts,” he adds.
More recently, he observed that colts and fillies exhibited more stress when working in mixed groups. “Training horses in sex-mixed groups is not recommended,” Kedzierski says.
How Much is Enough?
We’ve established that early exercise benefits these animals, but what comprises “appropriate”? Our sources note that science hasn’t determined the specifics.
It comes down to “good common sense,” says Lepeule. “You just have to know that if you leave your foal closed up all the time, that’s not good. Or if you leave your foal outdoors all the time and exercise him intensively, that’s not good, either.”
Smith agrees. “There’s always a balancing act,” he says. “If you give them too much exercise, you can cause damage, and we have data on that as well.” Unfortunately, data on adaptive exercise levels is limited, and scientists can’t use it to draw specifics on how much exercise is too much.
So what’s a breeder or an owner of a young horse to do? Smith says probably the best advice is to raise growing horses in outdoor pastures. “Our research demonstrates that the exercise the young horse takes out at pasture produces as good an effect on tendons as what we could achieve by adding extra exercise,” he says, based on studies by the Global Equine Research Alliance—a collaboration of universities from four countries supported by the Horserace Betting Levy Board.
Smith adds that observations made during a collaborative study with the Japan Racing Association’s Equine Research Institute, using GPS and visual monitoring of foals at pasture, showed putting distance between foals’ water sources and food is a good way to encourage pastured youngsters to stay active. “This naturally increases the amount of exercise they do as they play a lot between those two areas,” he says. “It’s a very simple management tool.”
Even so, be reasonable with pasture size, Smith warns. Extremely large pastures for mares with foals can lead mares to travel long distances with their young foals that could become too tired to keep up. Very large pastures also increase the risk of osteochondrosis in foals younger than two months, Lepeule warns.
Whatever you do, make sure you’re not locking them up in stalls constantly. “People who don’t exercise their young stock at all are going to experience a deleterious effect,” says Smith.
Starting your horse in the right conditioning program also requires good sense, keeping in mind the horse’s ability to adjust to additional exercise. Similar to a human athlete that must build to higher intensity training incrementally, a horse’s work should begin gradually and build up slowly in phases, says Clayton. “Problems occur when the conditioning process proceeds too rapidly in young horses,” she notes. “The trainer needs to allow adequate time for tissue adaptation and strengthening.”
A Word of Caution
Although young horses are capable of quite a bit of exercise, some kinds of activities are better held off until later.
“In young horses, avoid high speeds or high-intensity work, especially on hard surfaces,” Clayton says. “They also shouldn’t be jumping large fences or going downhill at speeds faster than a walk. This kind of work is tough on the bones and joints because it involves high concussion.”
She also recommends holding off on any work that involves rapid turns or spins until the horse is fully developed. Different breeds mature at different rates, so consult your veterinarian for advice on timing your horse’s training.
Despite all our best intentions and efforts, accidents can still happen. So it’s a good idea to be aware of warning signs that you’ve gone too far or that the horse has suffered a mishap. Watch for soft tissue swelling, lameness, a reluctance to work, or a sour attitude, Clayton says.
If you see these warning signs, the best thing to do is stop exercise and call your veterinarian. “If you get to that stage, it’s very important that you don’t continue (your exercise program),” Smith says.
Take-Home Message
If we use good sense in managing our youngsters, we can help protect their musculoskeletal systems over the long term with proper exercise. And that can help keep athletes healthier and prevent layups during their athletic careers.
“The single most important reason for horses to lose days of training or competition is locomotor injuries,” says Clayton. While we can’t prevent all injuries, we can plan ahead. If we do it right, we can give our young horses every chance of having the strong bones, resistant tendons, energetic muscles, and star attitude of the world’s greatest equine athletes.

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