ANTIAGING NUTRITION
MUSCLE BUILDING L-CARNITINE
L-Carnitine
L-carnitine is very similar to the nonessential amino
acid carnitine. It performs some of the same functions,
such as helping metabolize food into energy.
L-carnitine is perhaps more widely known for its fat
burning, dieting support properties than for its contribution
to muscle building. In dieting, it is also known to
reduce feelings of hunger and weakness. In body building,
L-carnitine supplementation promotes development and
growth of muscle and delaying muscle fatigue. It is
also widely used for fat-burning and increasing energy.
Published studies show L-carnitine is useful in increasing
the heart's output and improving it's functioning, as
well as stimulating the heart's energy supply and improving
cardiac performance.
The body needs lysine, methionine, vitamin C, iron,
niacin, and vitamin B6 to produce carnitine.
L-carnitine is very similar to the nonessential amino
acid carnitine. It performs some of the same functions,
such as helping metabolize food into energy. It is widely
used for both its fat-burning and increasing energy
properties in dieting and in muscle building.
Benefits of L-Carnitine to Dieting
- Reduce feelings of hunger and weakness.
- Increases energy
Benefits of L-Carnitine in Muscle Building
- L-carnitine supplementation used in conjunction
with exercise programs has been shown to:
- promote development and growth of muscle
- delay muscle fatigue.
- Reduce post workout muscle soreness.
- Increase energy.
Disease Fighting Benefits of L-Carnitine
L-carnitine has also proven beneficial for those suffering
from:
- Cardiac Failure - cardioprotective activity
and beneficia affects on cardiac function.
- Hypertension - vascular protection properties
from its ability to lower triglyceride levels and
increase levels of HDL-cholesterol
- Alzheimers & Dementia - neuroprotective
activity
- Beta thalassemia - an
inherited, fatal form of anemia common in people of
Mediterranean descent. Remedial blood transfusions,
can eventually result in iron overload. L-carnitine
stabilizes red blood cells may decrease the need for
blood transfusions.
- Diabetes - no evidence that L-carnitine
will prevent diabetes, although abnormal carnitine
metabolism is associated with diabetes.
Physiology
L-carnitine is manufactured in the body from the amino
acids lysine and methionine. Niacin, vitamins B6 and
C, and iron are involved in its biosynthesis. It transfers
long-chain fatty acids, such as triglycerides into the
cells energy centre, the mitochondria, where they may
be oxidized to produce energy.
Studies
Patients with diabetes and high blood pressure were
given 4 grams of L-carnitine per day in an preliminary
study. After 45 weeks, irregular heartbeat and abnormal
heart functioning decreased significantly compared with
non-supplemented patients.
For congestive heart failure, a number of studies have
shown marked improvements. For instance:
- 500 mg per day of 500 mg PC per day, a modified
form of carnitine [propionyl-L-carnitine], led to
a 26% increase in exercise capacity after six months.
- 1.5 grams PC daily for 15 days showed a 21% increase
in exercise tolerance and a 45% increase in oxygen
consumption.
Studies on athletic performance enhancement have been
inconclusive.
- Trained athletes given 2 grams of L-carnitine two
hours before and after a 20 km run failed to demonstrate
improved physical performance or exercise recovery.
Other studies have been more positive:
- 2 grams of L-carnitine taken twice per day for
two to four weeks led to positive changes in lung
function and metabolism during exercise.
Sources
L-Carnitine is found in avocados, dairy products,
red meats [especially lamb and beef] and in fermented
soy products, e.g. tempeh. It can also be obtained through
nutritional supplementation.
About 60 to 75% of L-carnitine from food is absorbed.
The percentage absorbed from supplements appears to
be lower [one study showed only 20% of a 2-gram dose].
Symptoms of Deficiency
Carnitine deficiencies are rare, even in strict vegetarians,
because the body produces carnitine relatively easily.
Muscle fatigue, cramps, or pre-mature aging are all
signs of possible deficiency.
Anyone deficient in protein or amino acids in their
diet could benefit from L-carnitine supplementation.
Pre-mature infants, vegan vegetarians, children, and
breast-feeding women may tend to be deficient.
Rare genetic diseases can cause a carnitine deficiency.
Also, deficiencies are occasionally associated with
other diseases, such as diabetes and cirrhosis.
Dosage
L-carnitine is a non-essential or conditional amino
acid. This means that most people do not need carnitine
supplements. However, if certain pathology or intensive
demands are placed on the body, supplementation may
be beneficial
For therapeutic use, typical amounts
are 1–3 grams per day
For muscle building and exercise performance:
2-4 grams of L-carnitine should be taken one hour before
exercise, for two weeks.
Side Effects
- L-carnitine has not been consistently linked with
any toxicity.
- The DL form of carnitine may be toxic and is not
recommended.
- Certain medicines may interact with L-carnitine.
Recommended L-Carnitine Products
Carnitine
Others
- NOW L-Carnitine
- Dymatize Dyma-Burn Xtreme
- Universal Super Cuts 3
- Ultimate Nutrition L-Carnitine
- NxCare Methyl Ripped
Carnitor (Sigma-Tau), Carnitine-300 (Key Company),
Carni Fuel (Twinlab), Mega L-Carnitine (Twinlab) and
Maximal Burner Carnitine (Bricker Labs), Proxeed (Sigma-Tau).
Key Amino Acids for Maximum Performance & Muscle
Building
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