The Development of Perform' N Win:
an Electrolyte Supplement for the Performance Horse
Perform'N Win (PNW) is an electrolyte supplement
that is specifically formulated to replace electrolytes (salts)
lost in the sweat of horses during the time that they are working.
The electrolyte product, manufactured and distributed by Buckeye
Feeds, Inc. of Ohio, was developed and tested by Michael I. Lindinger
and Gayle Ecker, researchers in equine exercise physiology at
the University of Guelph and the Equine Research Centre.
When horses are exercising, heat builds up
in the working muscles. The body attempts to avoid serious elevations
in core temperature by dissipating the heat. During exercise,
the most important route of heat loss is through the mechanism
of sweating, where fluid is secreted to the surface of the skin.
The sweat of the horse is very high in salts or electrolytes.
The main salts lost in sweat are sodium (Na+), chloride (Cl-)
and potassium (K+). Measurable amounts of calcium (Ca++) and
magnesium (Mg++) are also found in sweat. Horses performing very
hard work can lose more than three (3) gallons (or 12 L) of sweat
in 1 hour. It is more usual that they lose 1 gallon (or 4-5 L)
of sweat during 1 hour of moderate work when ambient temperature
is between 50-70øC. With hot, humid conditions the sweating
rate can double, with losses of 2 gallons (10 L) or more per
One U.S. gallon (~4 L) of
sweat will contain 1800 to 2400 mg of sodium, 1000 to 2000 mg
of potassium, 3500 to 5000 mg of chloride, 60 to 100 mg of calcium
and magnesium. The corresponding molar concentrations are: sodium
80 to 100 mmoles/liter, potassium 20 to 40 mmoles/liter, and
chloride 100 to 140 mmoles/liter.
One ounce (28.4 grams) of
Perform'N Win dissolved in 1 liter of water gives a solution
consisting of 50 mmoles/liter of Na+, 25 mmoles/liter of K+ and
80 mmoles/liter of Cl-. These concentrations are much less than
those found in sweat for a very good reason. Equine sweat is
a highly concentrated solution of salts. If horses ingested such
a concentrated salt solution, it would be difficult and inefficient
for the intestine to absorb the salts and water. In fact, water
would initially be pulled into the intestinal system from the
blood, effectively dehydrating body fluids. Therefore, to adequately
replace all of the electrolytes lost in one gallon of sweat the
horse should drink 1.5 to 2 gallons of Perform'N Win solution
(made up with 4 ounces PNW per gallon water). The extra water
will be beneficial for increasing body water turnover, improve
renal function, ensure complete rehydration and the kidneys will
normally excrete the excess.
The salts lost through sweating come from the
plasma portion of the blood, the fluid that is between all the
cells in the body (interstitial fluid), and the fluid that is
inside of the cells (intracellular fluid). Together the plasma
and interstitial fluids are termed extracellular fluid (outside
the cells). Most of the sodium and chloride, and much of the
water, lost in sweat comes from the extracellular fluids. Most
of the potassium and some of the water comes from the intracellular
fluids (water inside the cells). Fluids within the stomach and
intestines (gastrointestinal or g.i. tract) are also extracellular
and may provide a reservoir of water and salts that can be used
WHY REPLACE SALTS AND
WATER LOST THROUGH SWEATING?
The loss of water through sweating and ventilation
leads to dehydration. This dehydration results in loss of water
from the blood plasma, interstitial fluids and from inside the
cells. This may compromise the function of cells and tissues,
including skeletal muscle, g.i. system, heart and skin. Typically,
the appearance and performance of the horse will suffer, leading
to an early onset of fatigue.
A horse may have a water
deficit of 17 to 30 L following a 50 mile endurance ride. This
equates to a 4 to 7% loss in body weight. Research has shown
that even a 3% loss (about 13 L) of water may have a negative
impact on performance. Excessive dehydration compromises the
health of the horse and can lead to heat stress, tying up and
The loss of salts impairs
the ability of cells to function normally. Muscle cannot function
at optimal levels. For optimal function, it is therefore, important
to replace both the water and salts that have been lost.
When horses are dehydrated,
fast effective rehydration best occurs when sufficient amounts
of salts are administered with appropriate amounts of water and
carbohydrates. If only water is given, complete rehydration can
take from 12 to 24 hours. Feeding wet foodstuffs can decrease
this time. Our research has shown that horses given 3 ounces
of Perform'N Win in 3 liters (3/4 gallon) fully recover hydration
status within 45 minutes after the end of 1-2 hours of moderately
intense exercise. The horse that recovers hydration status rapidly
will eat better, feel better, and be less prone to post-exercise
fatigue and muscular cramping.
The horse that is prevented
from incurring a high level of dehydration during exercise (by
pre-loading Perform'N Win and giving Perform'N Win during breaks
in the exercise) will perform better, recover better and be better
able to prepare for the next day's work.
Pre-exercise Loading: Perform'N Win may be given up to 2 hours
before work. This provides a 'reservoir' of water and salts in
the gastro-intestinal system that we have demonstrated is available
and used during exercise to replace water and salts lost in sweat.
An amount of 1 gallon of water containing up to 4 ounces (114
g) of Perform'N Win would be appropriate for pre-exercise supplementation
2 hours before starting the exercise.
During Exercise: When exercise or work is to be continued for
more than 1 hour it would be appropriate to encourage the horse
to drink freely during breaks in the work. The horse may not
want to drink initially. It is normal for a horse to incur a
mild level of dehydration before the thirst response is stimulated.
For horses that are not drinking, the electrolytes should not
be given by syringe (electrolyte/water slurry) into the mouth.
The syringe approach may be okay, but it is important that the
horse has ingested at least one gallon of water before administering.
Otherwise, the concentrated solution will pull water into the
g.i. tract, away from the other tissues.
After Exercise: We recommend that horses that have worked sufficiently
hard to sweat be given about 1 gallon of Perform'N Win solution
(4 oz./gallon) for each hour of exercise. This amount may be
reduced if horses were taking Perform'N Win solution during the
period of exercise. This should be given as soon as practical
after the end of exercise so as to get a rapid rate of rehydration
and replenishment of body salts. It should be given during the
initial 1 to 2 hours after exercise, the sooner the better. The
capacity of the stomach is about 2-3 gallons in endurance horses
and fluid in the stomach empties very rapidly into the small
intestine. If the horse is freely drinking Perform'N Win dissolved
in a bucket of water, it is not possible to over-administer.
It is important to try to rehydrate horses
as much as possible prior to feeding. We do not recommend feeding
the horse hay and dry feeds until after administration of water
and electrolytes, thus feeding would occur at least 1 hour after
the end of exercise. This allows time for fluid and salt balance
to be restored. Dry foodstuffs in the gut will further dehydrate
an already dehydrated horse by pulling water and salts from the
blood into the intestine. This will greatly delay the recovery
process and put the horse at risk of developing dehydration related
problems. Exercised horses should eat soaked hay or a grain mixture
with added water. It is important to get lots of water into the
horse during the recovery period.
For further reading:
Ecker, G.L. (1995) Fluid and ion regulation:
a primer on water and ion losses during exercise. Equine
Veterinary Education 7(4):210-215.
Ecker, G.L. (1996) Management of horses participating
in endurance rides. Compendium on Continuing Education
for the Practicing Veterinarian. 18(5):566-567.
Ecker, G.L. and A. Rogers (1996) Championship
Condition. EQUUS 225:54-63.
Lindinger, M.I. and D.J. Marlin (1995) Heat
stress and acclimation in the performance horse: where
we are and where we are going. Equine Veterinary Education
Maughan, R.J. and M.I. Lindinger (1995) Preparing
for and competing in the heat: the human perspective.
Equine Veterinary Journal (Supplement 20):8-15.
PNW Administration Schedule
2 hours Pre-exercise up to 4 oz. with 1 gallon of water
During Exercise 2 oz. with .5 gallon or more of water
(at 45min to 1 hour intervals)
For 1 hour breaks up to 3 oz. with 2 gallons or more of
Recovery from Exercise 8 oz with 2 gallons or more of water
over a 1 to 2 hour period.
For a 50 mile endurance ride, sweat losses range from 15 to 30 L (4-8
gallons). As an example:
Pre-ride 1 gallon
15-20 miles .5 gallon
25-30 miles .5 gallon plus .5 gallon if 30+ minute hold
40 miles .5 gallon
Recovery 2 gallons
4.5 gallons + .5 = 5 gallons of PNW solution
I have been told to avoid electrolyte mixes with sugar. Is this
a problem with Perform' N Win?
It is true that supplements containing large
amounts of sugar should be avoided when using that supplement
before, during or after exercise to replace sweat losses. This
kind of supplement may cause sugar highs and lows. However, a
supplement without any glucose (a simple sugar) will not be absorbed
efficiently . There are transporters in the small intestine that
carry sodium, potassium and water, with glucose across the intestinal
wall into the bloodstream. The amount of carbohydrates in PNW
(approximately 3%) is balanced to ensure rapid absorption of
sodium, potassium, and water (for comparison, Gatorade has 6%
carbohydrates to promote electrolyte transport in humans). The
rapid absorption of the PNW supplement has been confirmed by
research at the Equine Research Centre, by using tracers to follow
the absorption of sodium and potassium. The ingestion of up to
3 ounces of PNW in 3/4 gallon of water will not cause sufficiently
large increases in plasma glucose to get a sugar high. It is
recommended that during exercise, not more than 2 ounces in 1/2
gallon water be administered at once.
Why can't you make it into a paste?
Some supplements are sold as a salt paste.
This highly concentrated material in the stomach will empty much
more slowly than water. It may take twice as long to be emptied
into the intestine and the recovery process is delayed considerably.
Also some pastes are manufactured in a corn syrup (high sugar)
base and as mentioned above, high sugar intake is not recommended
for the horse during exercise. These pastes also cause dehydration
of body fluids unless given with adequate amounts of water.
We do not recommend using salt pastes during
exercise as they disturb the fluid balance of the horse. This
has been confirmed by a team in Sweden (Nyman et al.) doing research
on endurance horses during competition. They recommend against
using salt pastes before and during exercise.
Can I make my own recipe at home for less money?
Yes, you can. However, the ratio of salts,
the form of salts and the proportions of salts vs. carbohydrates
is important for designing a supplement that will work optimally
during exercise. The PNW resulted in increased time-to-fatigue
(~23% longer exercise duration at a constant speed) when used
on horses under controlled treadmill conditions. The study also
showed rapid uptake and distribution into the blood and of K+
into the blood cells and skeletal muscle. Controlled tests have
found this supplement to be effective at quickly restoring water
and salt losses in exercising horses.
Powders in general, and PNW in particular,
ounce for ounce are about 10% of the cost of most commercially
available pastes when administered for a given ride distance.
What type of horse is this supplement suited for?
All horses undergoing prolonged (2 h or more)
exercise, including training and long walks in warm weather sufficient
to cause sweating. PNW is designed to be fed on a per hour of
exercise basis. This makes it ideally suited to the performance
horse. No guessing is needed about your horse's weight where
the dose of the supplement is based on body weight.
How is weight loss related to performance decrements?
The amount of weight lost during exercise is
predominantly due to sweat losses. If a 450 kg (1000 lb) horse
loses 14 kg (~30 lbs), this means that about 14 L of sweat has
been lost, or a 3% body mass loss has occurred. Recent research
shows that even a 3% body mass loss can have a negative effect
on performance in horses. A 3% decrease in body mass is equal
to about a 5% decrease in body water (5% dehydration). At the
Race of Champions, horses that lost more fluids (body mass) in
the early part of the ride finished at slower speeds than the
horses that maintained their body mass. In other words, a high
sweat loss that is not replaced early in the ride results in
a slower ride speed (poorer performance). It is important to
keep water and electrolytes going into the horse, even during
the early part of the endurance ride if a strong finish is desired.
Isn't water sufficient? Why do I have to add electrolytes?
Intake of water alone will actually dilute
the remaining fluids in the horse, decreasing the concentrations
of sodium, potassium and chloride in the blood. This dilution
can be a serious health concern because it leads to an imbalance
of electrolytes and increases the time it takes for full rehydration
and electrolyte replacement. It may also reduce the thirst response,
which is affected by the sodium concentration in the blood. The
composition of PNW with electrolytes and carbohydrates ensures
that rehydration occurs rapidly, and the bloodstream is quickly
absorbing the water and electrolytes it needs to recovery. The
Na+ is retained in the bloodstream and the rest of the extracellular
fluid where is retains water. The K+ helps retain water in the
muscle and the rest of the intracellular fluids. Testing has
even confirmed that the K+ in the PNW supplement enters the muscle
more rapidly than when K+ tracer is given with water. The maintenance
and restoration of K+ and water into the muscle is critical for
optimal and continued performance.
Do I need to give electrolyte supplements during the week when
If your work-outs cause sweating that lasts
for more than one hour each day, then using PNW in the water
after your workouts will aid in faster recovery. PNW is not designed
as a daily all-purpose electrolyte supplement, but many like
to use it during the week as well as during competitions and
training to maintain consistency.
Can I give PNW in any other manner?
Yes, as long as you know the hydration status
of your horse. If you prefer to administer the PNW as a slurry
or paste by syringe directly into the mouth, only do so after
the horse has had a good drink. PNW can be given in the feed
in morning for pre-loading. We know of one endurance rider that
makes PNW "cookies" to give his horse during the endurance
competitions. As such, they can be useful "rewards"
for the horse AFTER the horse has had a drink of water. They
could also be used at home to "train" the horse to
Do I need to give my horse electrolytes on short rides (<30
The answer to this question depends on the
conditions. If it is hot and humid, then giving your horse PNW
will help the horse during exercise and to help enhance the recovery.
Even though the distance may seem short, if the speed is higher,
or it is hot and humid, the horse can still lose more than 20
L (5 gallons) of water.
Will horses get enough salt from a salt block to replace the
If your horse is sweating more than 2 hours
a day, then it is unlikely to get enough salt in a short period
of time. Salt blocks are made for cattle. The horse may not be
able to lick enough salt to replace the losses. This is frequently
why you see horses chewing or scraping their teeth on the salt
block to get more. Providing free choice loose salt can help
avoid this problem. Also, some of the blocks contain other minerals
and substances. If the horse licks or chews the block enough
to satisfy the sodium requirements, it may be getting too much
of the other minerals that are not lost in sweat.
Isn't it bad to give the horse electrolytes during the week?
Don't we make the horse lazy in saving electrolytes?
Electrolytes cannot be "saved" or
"stored" for long periods. The only way we know of
to "store" electrolytes is to put them into the g.i.
tract, with water, before exercise. There is no evidence to show
that giving a horse electrolytes during the week makes him "lazy"
during the endurance ride. In fact, the opposite may occur. If
the horse is lacking in electrolytes from the hours of training,
it may be in a fluid and electrolyte deficit before the ride
even starts. The loss of water and electrolytes is an obligatory
result of heat dissipation. These losses, if not replaced, can
negatively impact on the performance and health of the animal.
For more information:
Gayle Ecker can be reached at
Mike Lindinger can be reached at
phone: 519-824-4120, ext. 3752
Michael I. Lindinger
Dept. of Human Biology Nutritional Sciences
University of Guelph, Guelph, ON Canada N1G 2W1
University home page: http://www.uoguelph.ca/