SPORTS MEDICINE: Cross-Training for Horses
By Ray J. Geor, BVSC, PHD, DIPL. ACVIM
To add variety to conditioning programs, human athletes often undertake
exercise sessions that are not specific to their athletic disciplines.
For example, long-distance runners might cycle on a stationary bike
once or twice a week, swim, or "run" in a swimming pool.
This practice, termed "cross-training," has two main goals.
First, it provides conditioning of the cardiovascular system (heart
and circulation); and second, it reduces the stress and strain on
areas of the body that are subject to considerable pounding during
heavy single-discipline training.
Does this practice of cross-training have a place in the horse world?
Given the unacceptably high rate of musculoskeletal injuries in
athletic horses, there is certainly a need for training methods
that provide the desired conditioning effect without over-stressing
joints, bones, tendons, and ligaments. The end result of this cross-training
perhaps could be a reduced risk for injury. In that regard, swimming
or exercise on an "underwater" treadmill could be a useful
addition to a horse's conditioning program.
Another consideration with the use of swimming pools and other forms
of exercise equipment, such as treadmills and mechanical walkers,
is the potential to save labor, time, and money. Horses can be exercised
without a rider, no special tack is required, and with some exercise
methods one can condition several horses in a relatively short period
of time. Conditioning on a treadmill or a mechanical walker also
takes some of the guesswork out of the training program. For example,
the duration and intensity of each workout can be precisely controlled
and the underfoot conditions held constant.
We will discuss several pieces of exercise equipment (mechanical
walkers, treadmills, underwater treadmills, and swimming pools)
that can be used for conditioning horses.
Mechanical Walkers
A mechanical walker (sometimes called a "European hot walker")
has become an extremely popular tool for light conditioning work.
Many large farms and sales prep operations rely heavily on a mechanical
exerciser for conditioning sale yearlings. These automatic systems
differ from traditional hot walkers in that there is no requirement
for the horse to be connected to a lead line (tethered) and pulled
by a moving arm. Rather, the exerciser is divided into separate
areas (typically six, but there can be as many as 10) by mesh gates
that are suspended from horizontal steel beams that form the spokes
in the wheel. The gates are 30-35 feet apart, and inner and outer
fences define the circular track (approximately eight feet in width).
In typical designs, the inner fence has a 60-foot diameter circle,
while the outer fence forms a circle with a 68-foot diameter.
Compared to traditional "hot walkers," which were primarily
designed for cooling out racehorses after training and racing, the
design of the mechanical walker allows more freedom of movement
and a greater variety of exercise options. Although walking and
trotting are the norm, these machines can operate at speeds up to
20 mph that allow for cantering work. Most have a wall-mounted control
box that includes an emergency stop button. By and large, horses
adapt easily to exercise in mechanical walkers and mishaps are rare.
Nonetheless, these machines should always be operated under supervision.
Mechanical walkers are also reversible, operating in clockwise and
counter-clockwise directions. Working the horse in both directions
allows for an "even" conditioning of the skeleton and
avoids undue stress on the "inside" limbs (particularly
the forelimbs). In general, horses should be exercised for no more
than 15 or so minutes in a single direction. In this regard, the
surface should also be forgiving. Materials such as a mixture of
wood fibers and shredded rubber provide the best footing, in my
opinion.
Although the initial investment is substantial (as much as $20,000),
the time and labor savings for large training and breeding operations
can more than justify the expense. The ability to exercise up to
10 horses simultaneously is a huge time saver, with a much lower
labor input. Many will use mechanical walkers for both warm-up and
cool-down activities, as well as longer-duration light conditioning.
These machines can also be used for rehabilitation of injured athletes,
although the smooth surface of a treadmill belt (or swimming) is
preferable in many cases. Still, for minor injuries, walking in
a mechanical exerciser is beneficial and certainly a time saver
when there are several horses which would have otherwise required
hand walking as part of the rehab process.
As with anything new, the horse needs a gradual introduction to
exercise in a mechanical walker. Start with a few sessions of walking
(10-15 minutes each). Once the horse is comfortable at the walk,
try a few laps of low and medium speed trotting. Also accustom the
horse to movement in both directions. When these tasks are mastered,
you are ready to incorporate the mechanical exerciser into your
horse's overall conditioning program.
Treadmills
The use of treadmills for conditioning horses has increased greatly
in recent years. Several different models are available, the main
differentiating features being size, speed capabilities, and price.
Lower-end models are available for $15,000-$20,000, while some of
the higher-end models cost more than $60,000 when installed. The
latter are typically capable of speeds greater than 45 mph and are
termed high-speed treadmills. These models are necessary if fast
work is to be carried out on a treadmill. On the other hand, if
the treadmill is to be used only for walking and trotting exercise,
the lower-cost models will do the job just fine.
Most treadmills have a hydraulic lift that allows for adjustments
to the incline (typically up to 10° of slope). The combination
of adjustable speed and incline provides ample variety in a horse's
conditioning program.
Use of a treadmill for at least part of a conditioning program offers
several advantages. One, the treadmill belt provides a smooth, consistent
surface. Many models also have shock absorbers under the treadmill
plate, providing a "cushioned" surface. Particularly during
the winter months when outdoor surfaces are muddy, frozen, or both,
this consistent surface can help prevent injuries from uneven footing.
During the depths of winter in northern climes when deep snow or
frigid conditions prevent outdoor exercise, access to a treadmill
can make a real difference in terms of a training program's consistency.
Another advantage is the ability to control the intensity and duration
of a conditioning session. Conditioning can be further refined if
the horse wears a heart rate (HR) meter during treadmill exercise.
When the HR is in the 140-160 beats per minute (bpm) range, energy
is mostly provided by aerobic metabolism; above 170 bpm, there is
considerable anaerobic metabolism. Therefore, the workout can be
tailored to emphasize aerobic or anaerobic conditioning.
Because the horse is stationary relative to an observer while moving
on the treadmill, a trainer can quickly evaluate gait and detect
lameness problems, or evaluate improvement in horses recovering
from leg injuries. The smooth, cushioned ride of a treadmill is
particularly useful for rehab work.
Horses quickly adapt to running on a treadmill, often within three
to four sessions, depending on the temperament of the individual
horse. Two to three handlers are used during the acclimation process,
although fully trained horses can be safely exercised with only
one or two people.
The nature of a treadmill workout will largely depend on a horse's
athletic discipline and the stage of his training program. For a
horse recovering from a tendon injury, initial workouts might be
as little as five to 10 minutes of walking, building up to a combination
of walking and trotting.
In general, treadmill workouts should attempt to mimic over ground
conditioning, with a combination of slow work (aerobic training)
that strengthens the skeleton and improves stamina, and faster work
(anaerobic training) that conditions the body for high-speed exercise.
Some trainers will require the horse to carry a weight saddle while
on the treadmill to simulate normal exercise conditions.
The treadmill is also ideal for a little "cross-training."
For example, incline walking and running is useful for building
muscle strength (particularly the back and hindquarters) and stamina.
Many endurance horse trainers use the treadmill with this goal in
mind.
However, no matter what type of training program is used, always
remember that a horse can become quite hot while working on a treadmill.
It is advisable to provide some type of cooling mechanism, such
as a fan, while he is working.
Although some horses (including racehorses) have been successful
when trained exclusively on a treadmill, my recommendation is to
use treadmill workouts as just one part of the conditioning program—rehabilitation
conditioning programs being the possible exception. Regardless of
athletic discipline, the horse requires some sports-specific conditioning.
Running on the treadmill is not the same as running over ground.
Proper strengthening of bones, tendons, and ligaments requires some
conditioning on the surfaces faced during competition exercise.
Also, the mental attitude of some horses can deteriorate when treadmill
conditioning is over-emphasized.
As a suggestion, limit treadmill conditioning to a maximum of 50%
of the total training volume, vary the nature of the treadmill workouts
to keep the horse interested, and keep each session relatively short
(no more than 15-20 minutes). Of course, bad weather and footing
conditions might dictate the need for greater emphasis on treadmill
conditioning. As well, some horses with a history of low-grade,
persistent lameness problems can remain sound when trained predominantly
on a treadmill.
Partially Submerged
A more recent addition to the array of exercise equipment available
for horses is the underwater treadmill, commonly called "aquatreds"
or "aquacizers." These machines, as the name implies,
are a combination of treadmill and swimming pool. A fiberglass tank,
similar in width to a regular treadmill, is partially filled with
water such that the horse is "submerged" to the point
of the elbow (or thereabouts) when standing on the treadmill. The
floor of the underwater treadmill has a treadmill belt and the sides
are fitted with jet ports that generate water flow during operation.
The underwater treadmill is best used for rehab work rather than
as a tool for primary conditioning, so you are more likely to see
these machines in large training centers or horse operations specializing
in rehabilitation. That said, many human runners who first used
water running as a means of injury rehabilitation have continued
to include pool sessions in their training program, claiming reduced
injury recurrence compared to a conditioning program of all road/
track work. Perhaps the same is true of horses.
As with swimming, the primary goal is to "unload" the
skeleton. Buoyancy of the water, in effect, reduces the horse's
body weight so there is less strain on the supporting structures
of the legs—bones, joints, tendons, and ligaments. Studies
in Japan (see Tokuriki et al. 1999) have shown that trotting in
a underwater treadmill requires less muscular movement than walking
on the same treadmill without water. The authors speculated that
buoyancy from the water was greatest during trotting, when the horse
repeats up and down movements.
Therefore, it is possible that walking is the best gait for exercise
in an underwater treadmill, providing some conditioning of the cardiovascular
and muscular systems while unloading the limbs.
To my knowledge, no studies have evaluated the effectiveness of
underwater treadmills for rehabilitation of leg injuries—for
example, tendon bows. Nonetheless, anecdotal evidence indicates
that horses which would otherwise be unable to exercise are able
to work in an underwater treadmill without deterioration of the
primary problem. This will allow for a faster return to full fitness
once normal conditioning is resumed.
Swimming
Swimming was perhaps the earliest version of cross-training for
horses. It first became popular in the 1970s and is still widely
used today. In contrast to the underwater treadmill, the horse is
almost completely submerged (the head stays above water) in a swimming
pool that is 10 or more feet deep. Therefore, the horse really has
to "swim" (paddling with all four limbs) to propel himself
forward in the pool. Research studies and clinical experience indicate
that short bouts of swimming (e.g., up to three or four laps of
a pool 15 meters in diameter) provides good cardiovascular conditioning.
And, because of the complete unloading of the skeleton, swimming
is an ideal choice for a horse rehabilitating from an injury. As
with the underwater treadmill, horses with a history of lameness
problems or older horses with worn joints and tendons can benefit
from regular pool sessions.
Of all the alternative exercise modes discussed here, swimming pools
represent the largest financial investment. Together with the expense
of pool installation, there is the cost of the large building required
to house it. As well, there are considerable maintenance costs,
and the requirement of very experienced handlers for operation of
the facility. So, practically speaking, swimming pools are not a
viable option for small training establishments. Still, you might
live close enough to an equine swim facility to be able to take
advantage of this exercise option.
For those lucky enough to live near the coast or another large body
of water, it might be possible to use a beach, lake, or even a river
to swim your horses. In some places, ocean swimming is a traditional
form of horse conditioning. This is best done in shallow water with
fairly even and firm footing—the workout will be very similar
to that undertaken on an aquatred. A number of precautions should
be taken before undertaking this type of exercise. In particular,
you need to evaluate the depth of water in the targeted area and
ensure that it is free from debris and provides reasonably firm
footing, and also beware of any dangerous wildlife such as water
moccasins or snapping turtles. A gently sloping, sandy beach is
the best choice.
There are pros and cons to each of the alternative exercises. Regardless
of exercise mode, however, it is important to understand that none
can completely replace a traditional training program. At least
some of a horse's conditioning must be specific to its athletic
discipline.
FURTHER READING:
Briggs, K. Equinomics: Exercise equipment. The Horse, March 1999,111-116.
Porter, M. Indoor exercise in winter. The Horse, December 1998,85-90.
Tokuriki, M.; Ohtsuki, R.; Kai, M.; et al. EMG activity of the muscles
of the neck and forelimbs during different forms of locomotion.
Equine Veterinary Journal. Supplement 30, 231-234,1999.
About The Author
Ray Geor, BVSc, PhD (equine exercise physiology). Dipt. AC VIM,
is currently employed by R and J Veterinary Consultants, Guelph,
Ontario, specializing in equine internal medicine, nutrition and
sports science.
©2001, The Horse All rights reserved.
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