As a dedicated marathon runner always chasing down a new PB / PR, I’m all over ergogenic aids and using food strategically to enhance my performance. For example, using caffeine and beet juice have turned out to be quite advantageous to my race results. So when I began my latest round of fat-loading (also a strategy that’s benefited my performance in the past), where I was eating rather large amounts of coconut oil, I thought I’d take a deeper look at medium-chain triglycerides and how/if they might be used strategically for running performance. After all, they’ve been thought to conserve glycogen stores and enhance performance by burning more fatty acids for fuel.

Medium-chain triglycerides (MCTs) are found in coconut oil, palm kernel oil and are also sold as supplements. Because they are more rapidly absorbed in our digestive tracts than other types of fats, they are more readily used for energy instead of being stored as fat. This bodes well for anyone wishing to lose weight (and studies such as this 2012 review of 14 studies confirm MCTs may be used as an acceptable form of weight control). Although it’s interesting to note the caloric intake must be kept the same (or reduced) – simply switching out other fats for the medium chain fatty acids gram for gram. Of note, this may help play into weight loss due to the fact MCTs contain only 8.3 calories per gram (compared to all other fats which contain 9 calories per gram).

Additionally, given how the fat is absorbed and utilized by the body, it’s been theorized that athletes (aka endurance runners) hoping to conserve glycogen stores would also benefit from MCT use just prior to exercise. This sounds appealing to someone like myself, who goes through a pre-marathon 10-day fat-loading process in an attempt to teach my body to conserve glycogen stores come race day! Would consuming coconut oil on race morning enhance this effect?

In short, probably not. MCTs have been found in studies to promote weight loss but have not been proven to be beneficial to exercise performance. While two studies to date have shown an improvement in exercise performance, the majority indicate that MCTs are ineffective as ergogenic aides.

Of note (and particular concern to someone like myself who has a sensitive digestive system), one study looking at the effectiveness of MCTs found that half the subjects experienced GI symptoms with MCT ingestion. Which made me feel better to see this because I’ve personally experienced GI distress after using coconut oil before running and wondered what was wrong with me. Knowing that 50% of athletes might experience GI symptoms with coconut oil, palm oil or MCTs supplement pre-exercise at least let me know I’m not alone. This same study also concluded that MCTs did not enhance performance – in fact, every single subject experienced an impairment in performance.

Renowned sports nutritionist experts Louise Burke and Vicki Deakin, in their textbook Clinical Sports Nutrition, look specifically at 6 studies ranging from 1996 to 2005 – only one study on their list (1996) actually showed improvement in performance, 4 showed no improvement and one showed impairment of performance. They summarize there is little evidence to support MCTs as an ergogenic aide.

Personally, I’ll continue to limit the amount of coconut oil I use the night before and morning of runs and especially races. I don’t recommend using MCTs as a supplement and am not a fan of using coconut oil pre-run. However, by all means please do continue to use coconut oil in all your cooking and baking as it is one of the healthiest fats and best oils to cook with. In fact, I may have just gone through an entire 16oz jar of coconut oil last week alone during my 10-day fat-loading (I’m now in my 3-day carb-load phase!!)… Tune in next week to find out how my marathon this weekend plays out.

To good eats and strong running… Cheers,

Sarah J Cuff, RHN

PS. Check out this awesome story of how “eating 2 run” helped Ally Ginther run a PB only 3 weeks after beginning her program. Before coming to see me, she would sometimes sleep 9 hours and still feel exhausted. Now she wakes up before her alarm even goes off, feeling alert and ready to go! Click here to read more about why Ally recommends Eating 2 Run to anyone who wants to better their running through more than just training, or who is struggling to get through injuries or anemia while training.