Three people cycling on road

Up your game with L-carnitine

02 Feb 2023 • 1 min read

If you’re a fan of endurance sports, this nutrient may be just what you need to get past the finish line. Hands up if you’ve ever taken part in endurance sports like long-distance cycling, running or hiking? Then you’ll know there’s a point where you start wondering if anything can keep you going that little bit longer. This is where some scientists think L-carnitine could help give your performance a push.

What is L-carnitine?

L-carnitine is an amino acid, a ‘building block’ for protein. We produce it naturally in the liver and kidneys, and store it in muscles, sperm, brain and the heart.1 Our bodies need L-carnitine to help convert fatty acids into energy. Its main job is to escort fat into each of our cells’ engines, or mitochondria. Once inside this power hub, fats are broken down and converted into energy, which can be used to fuel our muscles during exercise.2 Handpicked content: 11 ways to fit exercise into your daily routine

Where can you find L-carnitine?

We make most of the L-carnitine we need in our body, but you can also find it in small amounts in dairy foods, fish, meat, and wholewheat foods.3 If you eat a balanced diet, you should get enough L-carnitine from your diet alone. However, if you’re a vegetarian or vegan, are training for an endurance sports event, or regularly take part in intense exercise, it may be worth taking a supplement to top up your levels.4 Handpicked content: A quick guide to veganism

How does L-carnitine boost exercise performance?

L-carnitine is important for producing energy, but it also has a number of exercise benefits on the body.

It reduces lactic acid

For endurance athletes, one of the major benefits of L-carnitine is that it removes the waste produced by converting fat into energy back out of our cells. This waste is lactic acid. It is produced when you’re exercising so hard that you don’t breath in enough oxygen. Removing lactic acid from our cells’ engines helps to delay feelings of tiredness and muscle soreness.6 Handpicked content: How to fight fatigue

It may improve post-exercise recovery

A study published in the journal Nutrition in 2004 found that L-carnitine supplements help prevent cell damage and speed up post-exercise recovery.7 Although the study was carried out on athletes, it may be beneficial if you’re training for an event or stepping up your exercise programme too.

It could make you faster

A trial by Florida Atlantic University in 2009 revealed that short-term supplementation of L-carnitine helped 24 fit men perform more powerful sprints on stationary bikes than the control group.8 They also produced significantly less lactic acid, helping them recover more quickly after exercise.
Advice is for information only and should not replace medical care. Please check with your GP before trying any remedies.
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1. National Institutes of Health. Carnitine. Available from: 2. As above 3. As above 4. WebMD. L-Carnitine. Available from: 5. As Source 1 6. Stephens F, et al. New insights concerning the role of carnitine in the regulation of fuel metabolism in skeletal muscle. Available from: 7. Karlic H, Lohninger A. Supplementation of L-carnitine in athletes: does it make sense? Available from: 8. Jacobs P, et al. Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males. Available from:
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