Now, let's turn our attention
to fitness and its role in the overall welfare of the horse.
In this lesson, we'll discuss the characteristics of
cardiovascular and muscular skeletal fitness
and how to assess a horse's fitness in these areas.
By the end of the lesson,
you'll be able to identify the characteristics of a horse that is fit.
A great deal of injury can be prevented by maintaining adequate fitness.
Becoming fit requires balancing the level of exercise,
so that any damage created by exercise can be
repaired and so that the bones in the body can adapt to the change in load.
Once a horse is fit,
it takes relatively little work to maintain that fitness and bone mass.
A common error in both human and equine athletes is over training,
which can lead to repetitive use injury.
Ideally, horses should work at the level they usually perform
at only twice a week with light training intervals in between.
You should avoid large swings in activity.
Let's look at cardiovascular fitness for a moment.
Horses are obligate nose breathers,
meaning they cannot inhale through their mouth because of their long palates.
They can only exhale through their mouth and inhale through their nostrils.
Also their respiratory rate is dependent upon their stride frequency.
They inhale when their front feet leave the ground,
and they exhale when they contact the ground at the upper gate.
This means that a horse's respiratory rate is
not a good indicator of his overall fitness,
because of the differences in the natural stride length among individuals.
However, heart rate at peak performance and the time it takes to return to
normal heart rate after exercise are both good indicators of fitness.
For instance a horse working at peak performance should
take about 10 minutes or so to return to normal heart rate.
If the recovery time is greater than 10 minutes that can
indicate that there is a lack of fitness or other cardiovascular issue.
Equine athletes are very similar to human athletes in their response to training.
Their level of cardiovascular fitness increases
their ability to deliver oxygen to all tissues while exercising.
Horses also develop muscular skeletal fitness which allows their muscles,
tendons, ligaments, and bones to adapt to the demands of their work.
While cardiovascular fitness can be developed over several weeks,
muscular skeletal fitness takes longer to develop.
This is the reason why the rate of
muscular skeletal injury goes up after periods of rest.
Some equestrian disciplines like endurance,
racing and eventing require that the horse demonstrate
cardiovascular fitness in order to safely continue on course.
Interval training is used in horses to develop
both cardiovascular fitness and muscular skeletal fitness.
Like in humans, interval training is
the gradual introduction of more intense exercise over longer periods of time.
The surface the horse is working on, the depth,
and the resistance of that surface as well as the body condition of the horse,
the length of the horse's hooves and the presence of pain,
all can significantly impact the amount of calories and effort the horse has to expend.
Now, let's discuss muscular skeletal fitness for a moment.
Bones are living structures capable of healing and re-modelling,
meaning that they can adapt to the forces that come down the limb and they can
lay down additional bone to create greater support in areas that are highly stressed.
The bones of young race horses for instance,
will thicken to better distribute the force of the gallop over a moderate distance.
However, even with the ability of bones to repair and remodel themselves,
excessive training schedules in any discipline
can increase the likelihood of bone injury.
Horses should be given the sufficient rest between
work sessions in order for the bone to fill in any microdamage and remodel.
In the case of a fracture resulting from excessive training,
it can take the bone three to four months to
heal and even longer if the fracture is not stable.
Soft tissue injuries include injuries to the muscles, tendons,
and ligaments which are the structures that
support the muscular skeletal system and bones.
Horses with tendon and ligament injuries need
several months of controlled rehabilitation to properly heal.
Tendons and ligaments often heal with scar tissue that
is not as dynamic or flexible as the original structure.
That is why some horses develop recurrent soft tissue injuries.
The rehabilitation of a soft tissue injury should be overseen by a veterinarian.
And work should be gradually increased
based on the horse's response to controlled exercise.
Free turnout after an injury or uncontrolled exercise results in
the poorest prognosis for the horse to return to
the formal level of athleticism and should be avoided.
We know that injuries to the muscular skeletal system can result in
long periods of recovery or even the end of an athletic career.
In the next lesson, we'll discuss preventative measures for
keeping your horse in peak condition through a fitness plan.
Claudia Sonder, DVMEmeriti Director of Equine Outreach
