7
SWEAT AND THE PERFORMANCE HORSE
ACIDOSIS AND ALKALOSIS
A horse’s blood has a pH of 7.4 – 7.45, making it very slightly
alkaline. It is very important that a horse’s blood pH is kept within
these levels for the horse to function correctly. Fortunately a horse’s
system is very good at maintaining this, but to do so it requires the
right electrolytes and fluids to be available
The pH Scale
pH 1
ACIDIC
pH 7
NEUTRAL
pH 14
ALKALINE
EXAMPLES OF DIFFERENT LEVELS OF
ELECTROLYTES LOST IN DIFFERENT SPORTS.
Sport
Sweat rate
At risk of:
Barrel Racing
Light
Acidosis
Cutting
Light
Acidosis
Racing
Light
Acidosis
Showjumping
Moderate
Alkalosis
Showing
Moderate
Alkalosis
Dressage
Moderate to Heavy
Alkalosis
Hypochloraemic alkalosis results in poor performance, blowing or
‘thick windedness’ or nervousness as a result of an increased ratio of
bicarbonate to chloride in the blood.
Pacing
Moderate to Heavy
Alkalosis
Polo/Polocrosse
Moderate to Heavy
Alkalosis
Western Pleasure
Moderate to Heavy
Alkalosis
Acidosis
Endurance
Heavy
Alkalosis
Eventing
Heavy
Alkalosis
Stock work
Heavy
Alkalosis
Horses kept in hot,
humid conditions
Heavy
Alkalosis
pH 7.4 – 7.45
Horse’s blood
Horse’s blood dropping
below 7.4 is called Acidosis
Horse’s blood rising above
7.45 is called Alkalosis
Alkalosis
Horses exercising at a very high intensity for a shorter period of time
will lose less sweat, but will produce excess lactic acid in
their muscles which can lead to acidosis. This lactic acid is
transferred to the blood causing it to become more acidic. Acidosis
results in muscle fatigue and soreness, lack of stamina and can lead
to ‘tying up’.
All these electrolytes play a vital role in the horse’s body function
and all are lost in the horse’s cooling processes in differing amounts
depending on the activity being undertaken. This is why it is
necessary to supplement with a complete electrolyte which contains
the right balance for the requirement of the horse.
THE IMPORTANCE OF EQUINE ELECTROLYTES
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8
SWEAT AND THE PERFORMANCE HORSE
RECOVERY
Reducing Recovery Time
After a horse finishes a period of intense exercise, its heart rate is
still elevated and heat still needs to be expelled. Any lactic acid in the
system needs to be recycled and toxins and free radicals excreted.
Lactic acid is produced when the body burns energy in excess of the
amount generated aerobically (with oxygen). This is termed an oxygen
debt and has to be paid back at some point. It is paid back during
the recovery phase by converting the lactic acid back to pyruvate, a
process that requires oxygen. In this situation the horse will continue
to breathe heavily even after finishing exercise. This process is termed
‘repaying the oxygen debt.’ The heart rate will remain elevated as the
oxygen debt is repaid and also the horse will continue to sweat until it
has regained control over its elevated temperature.
B vitamins play an important role in recovery for horses which
have had a period of intense exercise, suffered from stress or illness.
B vitamins aid in building appetite as well as providing muscle and
blood repairing properties.
Whilst and after the oxygen debt has been repaid and the body
heat is gotten rid of, the kidneys will be filtering the blood and
removing toxic metabolites, the process of remodelling and
repairing any damage will start and the replenishment of energy
reserves will begin.
Vitamin E and selenium are powerful antioxidants that assist horses
which are prone to tying up by neutralising the damaging free radicals
that are naturally produced during hard exercise.
Lactic acid build up and the formation of free radicals are thought to
contribute to tying up. This can be countered with the aid of buffers
and mild diuretics. Citrate buffers are a natural bicarbonate precursor.
Adequate levels of these stored in the horse’s system enable it to very
effectively neutralise lactic acid before it can cause damage to the
muscles.
Any nutrients lost in this process, including vitamins, water
and electrolytes, then have to be replaced through the diet or
supplementation.
WHY DO MOST HORSES READILY
ACCEPT ELECTROLYTES IN THEIR DIET?
INTERESTING
FACT
In terms of nutritional requirements, salt is the
second most powerful driver in horses next
to thirst. If they are losing these salts through
sweat, their body will drive them to replace
these through seeking out salt in their diets.
THE SCIENCE OF SWEAT
THE IMPORTANCE OF EQUINE ELECTROLYTES
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