You have probably only heard about l-carnitine if you are in the health and fitness industry, where it is most widely used and talked about for its performance enhancing and fat burning qualities.
But let’s take a look at the science behind the hype and see if this really is a supplement worth its salt. In this post we will take a look at l-carnintine benefits and side effects to see if it’s suitable for your specific needs.
So What Exactly is L-Carnitine?
L-carnitine is a ‘vitamin type’ non essential amino acid related to the B-Vitamin family which is used in the body for transporting dietary fat into the mitrochondria. These are organelles that act a bit like a digestive system, taking nutrients from the blood, breaking them down and creating energy.
L-carnitine is produced in the liver and kidneys by the other amino acids methionine and lysine, and once produced is then stored in the muscles, heart, brain and sperm.
L-carnitine is mostly found in animal products and especially red meat (56-162mg per serving), but is also found at much lower levels in sorces such as poultry, fish and seafood (3-7mg) and dairy products (3-8mg).
What About Vegan Diets?
L-Carnitine can be found in plant sources such as tempeh, avocados and peanuts, but not at very high levels. The good news is l-carnitine deficiency is rare, even in strict vegans.
We can produce our own l-carnitine in our liver and kidneys from the other amino acids methionine and lysine, all of which are abundant in other plant foods such as nuts, seeds, lentils, wholegrains, tempeh, quinoa, seitan, black beans and soya milk.
This is the reason l-carnitine deficiency is rare because we have plenty of opportunity to make our own from the methionine and lysine we consume in our everyday food. Deficiency is usually only found in those who have kidney and liver function problems as they cannot produce their own adequate supply.
The Science Behind L-Carnitine
Commonly used in the fitness industry for its ability to stimulate the release of growth hormone and help reduce body fat, l-carnitine transports fatty acids into cells where they can be oxidised and used for fuel. This cellular reaction happens both when you are at rest, and during exercise itself. It is however, most effective when you are engaging in very intense exercise.
Without this amino acid it is very hard for fats to be burned as fuel – which is ultimately what most exercisers and body builders are trying to achieve.
L-CARNITINE BENEFITS AND SIDE EFFECTS
1. FAT BURNING
A study from the University of Nottingham confirmed that when the athletes in their trial consumed 2g of l-cartinine along with 80g of high G.I. carbohydrate, both as soon as they wake up and before food, then again 4 hours later for 24 weeks, they burned 55% less glycogen from muscles, whilst at the same time increasing ability to burn fat by 55%.
This means l-carnitine is a supplement that could actually help the body to burn fat more efficiently. AND, as it also has the ability to help your body burn less glycogen, means you will have more stamina to train for longer – hence you will burn more fat and build more muscle.
2. EATING HIGH GI CARBS AND NOT GAINING FAT
The athletes on the trial, although eating an extra 640 calories of high G.I. carbs, gained no extra body fat whilst supplementing the l-carnitine: while the group eating the extra carbohydrates without the supplement put on more than 5lbs in weight of fat.
This is not to advocate a high G.I. diet, as this was used as an example in the trial to prove how effective l-carnitine is at burning fat. Unless you really are working out like a true athlete then I would recommend sticking with a lower G.I. diet.
3. LESS FATIGUE
The subjects on the same trial that were supplementing the l-carnitine were also able to go a whopping 25% longer due to the fact that fat was being burned for fuel first rather than muscle glycogen, therefore staving off fatigue. This is the the reason l-carnitine allows you to train for longer periods before tiring.
4. LESS SORENESS AND FASTER RECOVERY PERIOD
L-carnitine has been shown to significantly reduce damage done to the muscles during exercise when taken at doses of 1-2 grams per day. It also decreases the muscle soreness you can feel for days after a hard workout which can lead to you missing sessions, or not putting your all in when you need to due to pain.
L-carnitine will aslo give you that edge during your training sessions by increasing blood flow and delivering more nutrients to the muscles when you need it most.
5. ANTI AGING
Yes you heard me right! L-carnitine boosts brain cells and helps to keep the brain young. Its powerful antioxidant effects slow down the aging process and help to keep the brain and heart young.
And this slowing down of the aging process does not just mean on the outside, but on the inside too as it will also lower your risk of age related degenerative diseases such as alzheimer’s and heart disease.
6. MORE TESTOSTERONE
Another great side effect of l-carnitine is higher testosterone which will boost muscle growth and strength. It’s all due to the fact that l-carnitine increases androgen receptors and boosts hormonal response to exercise.
Don’t worry you can still take this supplement if you are a woman without worrying about turning into Arnold Schwarzenegger, as the effects will be subtle and toned.
DOSAGE AND WHEN TO TAKE:
Depending on your weight, size and fitness regime you should take between 500 and 3,000 mg per day (that’s equivalent to 0.5-3 grams). The best time to take l-carnitine is with a meal that contains both carbohydrates and protein. This applies to some of the other forms available such as propionyl-l-carnitine and l-carnintine l- tartrate.
On the other hand, the form of l-carnitine called acetyl-l-carnitine is more readily absorbed by the muscles, brain and intestines when taken alone without food. This type of l-carnitine can be taken along with other healthy fat burners such as green tea, to boost effects.
You should incorporate lots of fat burning plant foods into your diet ALONG with any supplements for the best results and for the FASTEST way to get a great body. To do this, please check out this list of ‘Fat Burning Superstars’.
WHICH FORM OF L-CARNITINE TO TAKE
Acetyl-l-carnitine (the most common type used in the fitness industry) is more readily absorbed by the muscles, brain and intestines. This type should be taken alone without food and is able to cross the blood-brain barrier for the synthesis of acetylcholine, which is one of the brains primary neurotransmitters.
It is also good for the support of the cardiovascular and nervous system, and for memory and brain power. This form of carnitine also helps burn fat for fuel just like regular l-carnitine, but is actually primarily used for the other effects.
STRAIGHT UP L-CARNITINE
This form (which is another popular form in the fitness world) supports weight loss and boosts the body’s ability to burn fat for fuel. It does this by mobilising fat from storage to be burnt as energy, and this form should be taken with a high protein and carbohydrate meal (preferably after a workout).
It is worth noting that there are other primarily brain boosting forms of carnitine, such as Propionyl-l-carnitine and l-carnitine l-tartrate and these should also be taken alongside food.
CAN I TAKE BOTH FORMS?
The short answer to this is yes you can take both for extra fat burning power, but as explained previously, they should be taken at different times. You don’t necessarily need to take both though, you could just go with the acetyl-l-carnitine which will give you the best of both worlds.
Take this first thing before breakfast, maybe along with a green tea (which is a fat burner) to boost brain power and cognitive function for the day – plus reap the fat burning benefits as well.
On a side note, acetyl-l-carnitine is sometimes marketed as N-Acetyl Carnitine (abreviation NAC), and these are both exactly the same thing but with different names.
Possible Side Effects:
If the dosage is correct for you and kept within the recommendations then there are very few side effects to l-carnitine supplementation, making this a mostly safe and popular supplement.
Side effects when they do occur include nausea, vomiting, stomach cramps and diarrhea, but this only usually happens when taken at too high a dosage. More serious side effects can include elevated heart rate, high blood pressure and fever, in which case the supplements should be stopped immediately and medical advice sought.