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L-Carnitine is available
either from the diet (if animals are carnivores such as greyhounds,
which eat meat, or in humans eating meat and dairy products), or from
very limited biosynthesis in the liver of horses (as plant materials are
very low in available L-Carnitine). Typically, horses are unable to
synthesise sufficient L-Carnitine for their normal requirements when
training and racing. L-Carnitine is synthesised from the amino acids
L-lysine and L-methionine. Supplementation of athletic animals and
humans is recommended.
L-Carnitine is classed as a “conditionally essential” nutrient in
humans, and is routinely used in supplementation of patients on drip
nutrition, as well as those with liver, heart, kidney and muscle
disease. Importantly, L-carnitine is also routinely used in the
nutrition of newly born babies.
L-Carnitine is now available in a wide range of human diet and weight
loss products.
L-Carnitine is very well researched in human and animal performance, and
is known as an “ergogenic aid” – a natural product which enhances
performance.
What Does L-Carnitine Do?
L-Carnitine is a water soluble amino acid which attaches to medium and
long chain fatty acids, transporting them into the mitochondria in all
cells (the part of the cell which converts fat into energy for the
cell). Through this absolutely essential process, L-Carnitine helps
reduce the storage of body fat, and the amount of fat in the blood. In
other words, adequate L-Carnitine helps the body use fats for energy
production rather than depleting the more critical energy reserves of
glycogen.
L-Carnitine is absolutely essential in the process of transporting fats
into cells for energy (ATP) production. By doing this, it acts as a
buffer by delaying the accumulation of lactic acid in muscle cells and
then blood when animals are working at maximum exertion. By delaying
lactic acid production with subsequent muscle fatigue, endurance and
stamina are extended in performance animals and humans.
Heart muscle relies almost totally on fats as an energy source, so
adequate L-carnitine is essential for normal heart function.
What happens if there isn’t enough L-Carnitine?
Training and racing animals have much higher physiological demands for
essential nutrients, including L-Carnitine, and availability from
biosynthesis and/or diet may often be inadequate. This can create a
deficiency in energy production ( remember that fats are rarely limiting
as energy sources, even in thin greyhounds. Glycogen, or carbohydrates
are almost always the limiting energy resource in any performance animal
or human). Almost all of the energy used in endurance exercise is
fuelled by fats.
If a performance animal is unable to utilise fats as an energy source
properly, particularly when endurance exercise is performed, the
deficiency of L-Carnitine can cause skeletal muscle dysfunction,
weakness and fatigue, as well as heart enlargement, heart failure and
rhythm disturbances.
Many trials have confirmed a link between the L-Carnitine content of
skeletal muscles and the capacity to convert fats into energy in
athletic horses, dogs and humans.
In other words… the level of L-Carnitine in muscles plays the major role
in determining the exercise capacity of muscles.
High fat diets have regularly been promoted as having an energy content
of about 2.5 times that of glycogen stores w/w, however the high fat is
unable to be utilised unless adequate L-Carnitine is available at the
correct time in muscle stores. So – without L-Carnitine, the body cannot
use fats as an energy source!
In sprint exercise L-Carnitine has an important role in converting
carbohydrates for energy in intense, short term exercise. Because a
horse can maintain maximum exercise levels for longer than most other
animals, the role of L-Carnitine in sprint performance is equally as
important as in the provision of energy from fats in endurance exercise.
There is ample evidence that levels of L-Carnitine in muscle and blood
plasma actually increase with training, so training actually can
condition the body to store more L-Carnitine over time.
“Loading” L-Carnitine may also enhance exercise performance in a fit
horse.
Muscle fatigue is the major reason performance animals slow down towards
the end of a race. The muscles are tired and low on available energy.
(Energy availability is the key factor in limiting muscle performance).
If we can prolong maximum exertion levels, even by just a little, we can
improve performance. That’s the basic rationale for using L-carnitine in
performance animals.
Regular supplementation with L-carnitine improves maximum work output of
muscles in well trained, fit animals (by improving available energy
supply from fats, and by delaying onset of lactic acidosis and muscle
fatigue).
How to use L-Carnitine for performance
Provides L-Carnitine 200mg/mL
Recommended Dose: Horses: 10mL three times weekly
Greyhounds: 0.5mL/10kg bodyweight, three times weekly
Given with what else?
If trainers are supplementing L-Carnitine to improve the use of fats for
energy, and to improve endurance and stamina, as well as delay muscle
fatigue and lactic acidosis, it is obvious that L-Carnitine supplements
will be enhanced by regular supplementation with Racing Oil.
Any source of highly bioavailable, high energy medium chain
triglycerides (fats), as found in Racing Oil, given as a regular
supplement, will enhance the activity of L-Carnitine. The energy
available from fats is about 2.5 times greater than that from equivalent
glycogen (starch) sources, so by consuming fats as an energy source the
animal athlete is able to conserve glycogen for the severe exertion of
sprinting in the later stages of a race. Hence improving endurance and
delaying the onset of muscle fatigue.
L-Carnitine use in Greyhounds
Even though greyhounds eat a variety of meat and dairy products, it is
usually the case that greyhound diets are deficient in fats.
Interestingly, although greyhounds are lean, availability of fats is not
as limiting to performance as deficiencies in energy from starch
(carbohydrates).
Greyhounds do perform better, for longer, when supplemented with Sprint
Oil. Sprint Oil provides the fats required for energy production, so it
makes sense to provide additional L-Carnitine to fully utilise those
fats. In practice, supplementing Sprint Oil (to provide the medium chain
triglycerides) with daily L-Carnitine does provide dogs with extra
stamina and endurance, with a decrease in cramping and muscle fatigue
and pain. It is safe to supplement L-Carnitine daily in higher ,or more
frequent (twice daily) doses for 3-4 days prior to a race, and additional
Sprint Oil may be administered as well in this lead up to the race.
In both horses and dogs, L-Carnitine and Racing Oil or Sprint Oil as
applicable will help decrease muscle fatigue , cramping and pain, and
will help improve muscle recovery after hard work.
Other Uses for L-Carnitine:
Newborn Foals
Adequate L-carnitine levels are critically important for the survival of
newborn foals. After birth there is increased dependence on fat stores
for energy to maintain body temperature, as well as for other vital
metabolic processes. Adequate L-carnitine in the critical first days of
life is critical for foals, particularly those born in bad weather, or
with other illness or injury.
Precautionary supplementation of brood mares during the last few weeks
of pregnancy and during early lactation is strongly recommended, as this
raises milk L-Carnitine levels for the newborn foal.
Blood levels of L-Carnitine in foals and young horses are usually only
30-40% of that in adults. This reflects a poor ability to manufacture
L-carnitine in all young mammals, at the very time when adequate levels
are critically required.
Tying Up
There is some early trial evidence that the similarity of signs between
tying up or azoturia in horses and those seen in man from a deficiency
of one of the enzymes involved in L-Carnitine metabolism, makes it
possible that some of those horses have a similar metabolic defect and
would improve with L-Carnitine supplementation.
Breeding Males
There is ample evidence that L-Carnitine increases sperm maturation and
motility in stallions. Supplementation of stallions during the breeding
season when there is added performance stress could be of significant
use to many breeders.
Pig & Poultry Production
There are several European companies dedicated to the manufacture of
L-Carnitine products for intensive pig and poultry production. The
L-Carnitine is useful to control excess body fat in intensive piggeries,
and is well referenced.
Avian Use
Racing pigeon owners have long used L-carnitine supplements to improve
endurance and stamina in homing pigeons. There are, no doubt, other uses
in avian management as well, but don’t be surprised if pigeon fanciers
ask you for some product. |
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