Medium–Chain Triglycerides for Sports & Fitness
What is it?
Medium-chain triglycerides are a class of fatty acids. Their chemical composition is of a
shorter length than the long-chain fatty acids present in most other fats and oils, which accounts for their name. They are
also different from other fats in that they have a slightly lower calorie content1
and they are more rapidly absorbed and burned as energy, resembling carbohydrate more than
fat.2
Where are they found?
Medium-chain triglycerides are found in coconut
oil, palm kernel oil, and butter. Medium-chain triglycerides are also available
as a supplement.
Why do athletes use it?*
Some athletes say that medium-chain triglycerides
- helps increase endurance.
What do the advocates say?*
Medium-chain triglycerides are more easily absorbed and burned for energy than other fats,
which suggests they might play a role in supplying energy during exercise. Research results
have been quite mixed, however, and the large amounts required can lead to gastrointestinal
distress, which limits the usefulness of this supplement, even to the few athletes who might
benefit.
How much is usually taken by athletes?
Medium-chain triglyceridescontain a class of fatty acids found only in very small amounts
in the diet; they are more rapidly absorbed and burned as energy than are other
fats.3 For this reason, athletes have been interested in their use, especially
during prolonged endurance exercise. However, no effect on carbohydrate sparing or endurance
exercise performance has been shown with moderate amounts of medium-chain triglycerides (30 to
45 grams over two to three hours).4 5 Controlled trials using very large
amounts of medium-chain triglycerides (approximately 85 grams over two hours) have resulted in
both increased and decreased performance,6 7 while a double-blind trial
found that 60 grams per day of medium-chain triglycerides for two weeks had no effect on
endurance performance.8 A controlled study found increased performance when
medium-chain triglycerides were added to a 10% carbohydrate solution,9 but another
study found no advantage of adding medium-chain triglycerides,10 and a third trial
actually reported decreased performance with this combination, probably due to
gastrointestinal distress, in athletes using medium-chain triglycerides.11
Are there any side effects or interactions?
Consuming medium-chain triglycerides on an empty stomach can lead to gastrointestinal upset. Anyone with cirrhosis or other liver problems should check with a
doctor before using medium-chain triglycerides. Two reports suggest that medium-chain
triglycerides may raise serum cholesterol
and/or triglycerides.12
13 Medium-chain triglycerides are actually the preferred fatty acid source for cirrhotic
patients, but only when used intermittently.14
At the time of writing, there were no well-known drug interactions
with medium-chain triglycerides.
*Athletes and fitness advocates may claim benefits for medium chain
triglycerides based on their personal or professional experience. These are individual
opinions and testimonials that may or may not be supported by controlled clinical studies or
published scientific articles on medium chain triglycerides. For more complete and detailed
information, including references and safety information, see Medium Chain Triglycerides as nutritional
supplements.
References:1. Bach AC, Ingenbleek Y, Frey A. The usefulness of dietary medium-chain
triglycerides in body weight control: fact or fancy? J Lipid Res
1996;37:708–26.
2. Bach AC, Babayan VK. Medium-chain triglycerides—an update.
Am J Clin Nutr 1982;36:950–62.
3. Jeukendrup AE, Saris WHM, van Diesen RAJ, et al. Exogenous MCT
oxidation from carbohydrate-medium chain triglyceride supplements during moderate intensity
exercise. Clin Sci 1994;87:33.
4. Berning JR. The role of medium-chain triglycerides in exercise.
Int J Sport Nutr 1996;6:121–33 [review].
5. Goedecke JH, Elmer-English R, Dennis SC, et al. Effects of
medium-chain triaclyglycerol ingested with carbohydrate on metabolism and exercise
performance. Int J Sport Nutr 1999;9:35–47.
6. Van Zyl CG, Lambert EV, Hawley JA, et al. Effects of medium-chain
triglyceride ingestion on carbohydrate metabolism and cycling performance. J Appl
Physiol 1996;80:2217–25.
7. Jeukendrup AE, Thielen JJ, Wagenmakers AJ, et al. Effect of
medium-chain triacylglycerol and carbohydrate ingestion during exercise on substrate
utilization and subsequent cycling performance. Am J Clin Nutr
1998;67:397–404.
8. Misell LM, Lagomarcino ND, Schuster V, Kern M. Chronic medium-chain
triacylglycerol consumption and endurance performance in trained runners. J Sports Med
Phys Fitness 2001;41:210–5.
9. Van Zyl CG, Lambert EV, Hawley JA, et al. Effects of medium-chain
triglyceride ingestion on fuel metabolism and cycling performance. J Appl Physiol
1996;80:2217–25.
10. Angus DJ, Hargreaves M, Dancey J, Febbraio MA. Effect of carbohydrate
or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance.
J Appl Physiol 2000;88:113–9.
11. Jeukendrup AE, Thielen JJ, Wagenmakers AJ, et al. Effect of
medium-chain triacylglycerol and carbohydrate ingestion during exercise on substrate
utilization and subsequent cycling performance. Am J Clin Nutr
1998;67:397–404.
12. Cater NB, Heller HJ, Denke MA. Comparison of the effects of
medium-chain triacylglycerols, palm oil, and high oleic acid sunflower oil on plasma
triacylglycerol fatty acids and lipid and lipoprotein concentrations in humans. Am J Clin
Nutr 1997;65:41–5.
13. Hill JO, Peters JC, Swift LL, et al. Changes in blood lipids during
six days of overfeeding with medium or long chain triglycerides. J Lipid Res
1990;31:407–16.
14. Fan ST. Review: nutritional support for patients with cirrhosis.
J Gastroenterol Hepatol 1997;12:282–6.