I read a post by a guy in a Facebook group who claims MCT oil increases his athletic performance. I questioned him and he wrote:
However, when the body fat percentage gets low, you need the fats for energy to fuel your workouts. You have to reach steady state of fat in and fat/ketones out. I don’t think I could do my noon workout without my two cups of BPC in the morning. That’s my fuel…
When I asked if it was the MCT oil or the caffeine he replied:
… it’s the fat. Caffeine does not give you the ketones that allow me to lift heavy and do 30-45 mins of elliptical. Although, when I was very fat, my body provided the fat ketones. So in a sense I’m agreeing with you. There comes a time when you need that MCT fat that the liver turns into ketones as a priority.
Unfortunately the science doesn’t back up the claims.
Miriam E. Clegg. (2010). Medium-chain triglycerides are advantageous in promoting weight loss although not beneficial to exercise performance. International Journal of Food Sciences and Nutrition, 61:7,653-679.
Results indicate that MCT feeding is ineffective in improving exercise performance and future work should focus on the health benefits and applications of MCT.
Damien J. Angus, Mark Hargreaves, Jane Dancey, and Mark A. Febbraio. Effect of carbohydrate or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance. Journal of Applied Physiology. Volume 88 Issue 1. January 2000. Pages 113-119 .
These data demonstrate that carbohydrate ingestion during exercise improves 100-km TT performance compared with a sweet placebo, but the addition of MCT does not provide any further performance enhancement.
A E Jeukendrup, J J Thielen, A J Wagenmakers, F Brouns, W H Saris; Effect of medium-chain triacylglycerol and carbohydrate ingestion during exercise on substrate utilization and subsequent cycling performance. The American Journal of Clinical Nutrition, Volume 67, Issue 3, 1 March 1998, Pages 397–404.
…ingestion of MCT had a negative effect on performance…
compared with placebo ingestion, MCT ingestion had no effect on total rates of fat or carbohydrate oxidation, nor did it affect exogenous or endogenous carbohydrate utilization. The negative effect of MCT ingestion was associated with increased gastrointestinal complaints (ie, intestinal cramping). These data suggest that large amounts of MCTs (85 g) ingested during prolonged submaximal exercise may provoke gastrointestinal problems leading to decreased exercise performance.
Jeukendrup, A. E., A. J. M. Wagenmakers, F. Brouns, D. Halliday and W. H. M. Saris. Effects of carbohydrate (CHO) and fat supplementation on CHO metabolism during prolonged exercise. Metabolism 45(7): 915-921: 1996.
It is concluded that 29 g MCT co-ingested with CHO during 180 minutes of exercise does not influence CHO utilization or glycogen breakdown.
Another study found that MCT Oil increased liver size by adding fat to the liver (MCT Oil and Liver Size).