L-CARNITINE
Scientific
Name:
L-Carnitine
Type
of Nutrient:
Amino Acid
How
Supplied: Powder, Capsules,Tablet
Natural
Source:
Meat (Beef, Mutton, Lamb)
Used for:
Fat Loss, Energy
Legal
status: OTC
Availability: Health food shops, gyms
Cost
effectiveness:
*
Safety:
Good. NOTE: R-Carnitine - toxic
D-Carnitine
- toxic
DL-
Carnitine - toxic
Fats provide about 50% of your energy during aerobic
exercise and 80% of your
energy towards the end of long endurance events (Coyle E.F.
J Nutr 1992; 122:788-801).
You have to be able to burn them freely.
Carnitine absolutely controls fat use because it
forms the mechanism or transport system that moves the free
fatty acids into the mitrochondria (furnace part of cell)
where they are burned as fuel.
(Strack E et al Protides of the Biological Fluids.
New York: Elsevier, 1964:234)
Branch chain Aminos and Pyruvate are oxidised in the
energy cycle with the help of carnitine.
(Brewer J Physiol Rev 1983;63:1420-1480).
Carnitine inhibits the accumulation of lactic acid in
muscle (see Bicarbonate for Benefits of Lactic Acid
buffering). One
recent study of patients with angina being supplemented with
L-Carnitine showed the build-up of lactic acid during
moderate exercise was reduced by half, and the duration of
exercise was significantly increased. (Brevetti G, et al Circulation 1988;77:767-773).
Because of Carnitines roles in the above, the amount
of circulating carnitine in your muscles plays a major part
in their efficiency and the amount of energy they can
supply.
The standard textbook response is that a sedentary
person on a good diet doesn’t need to take L-carnitine
because the body manufactures carnitine from the amino acids
lysine and methionine (plus Vitamin C, niacin, pyridoxine,
and iron).
But athletes in heavy training put their bodies in a
state of stress that uses heaps of carnitine.
Their demand can easily exceed the bodies ability to
make it (Lennon DLF, et al J Appl Physiol 1983;55:489).
Moderate exercise, such as cycling on an ergometer
bicycle at only 55% of VO2 max, causes a 20% drop in muscle
carnitine (Lennon DLF, et al J Appl Physiol 1983;55:489).
A much greater drop is caused by maximal exercise (Siliprandi
N, et al Biochem Biophys Actu 1990;1034:17-21) putting
athletes into the same carnitine status as patients with
carnitine deficiency diseases.
Physiological
studies show that carnitine supplements inhibit the decline
in free carnitine in muscle caused by maximal exercise, and
completely prevents the decline in free carnitine during
endurance exercise. (Arenas
J, et al Muscle and Nerve 1991;14:598-604).
There is evidence that L-carnitine can boost both
anaerobic and aerobic performance.
HOW
TO USE
A dose of 2-4 grams taken for 2 weeks, one hour
before exercise appears to be effective.
This daily dose of L-carnitine shows no toxicity but
DL-carnitine is TOXIC and must never by confused with
L-carnitine, as they are two quite different compounds.
