Medium-chain triglycerides (MCTs) are a type of molecule, often derived from coconut oil, that may help promote optimal cellular energy and athletic performance through the unique way they are metabolized in the body. MCTs are digested and absorbed differently than other fats. They are more readily oxidized in the liver and converted to ketones, even in the presence of dietary carbohydrates. MCTs are absorbed directly into the portal vein from the intestine and delivered to the liver, bypassing conventional fat entry into the bloodstream via the lymphatic system, which makes them a quick source of energy. The liver may partially oxidize MCTs, but they are commonly and rapidly metabolized into ketone bodies that are exported and used in other tissues as an alternative source of energy, particularly the heart, brain, and skeletal muscles.

During exercise, our bodies use the readily available fuel stored as glycogen in muscles and the liver. Fatigue and other impediments to exercise performance may occur as a result of glycogen depletion or insufficient glycogen stores. Evidence from animal and clinical studies suggests that MCTs, as another source of fuel, may help support athletic performance. Because MCTs are hydrolyzed rapidly and absorbed directly by the liver, they may help promote ketone body utilization capacity while minimizing impairments to muscle carbohydrate metabolism during exercise. 

An animal study investigated the cellular changes that occurred in the presence of MCT intake and exercise. MCTs were shown to help improve skeletal muscle function and mitochondrial biogenesis through the upregulation of mitochondrial membrane ATP synthase and the activation of Akt and AMPK signaling pathways. 

A controlled murine study investigated the impact of long-term intake of MCTs on skeletal muscle integrity. When compared with the control group, the MCT group experienced a lower reduction in muscle and liver glycogen concentrations. Improvements in the ketolytic capacity in skeletal muscle, without inhibitory effects on carbohydrate metabolism, were also observed. 

The intake of MCTs may help support athletic performance, even while on a diet that includes carbohydrates. A double-blind crossover clinical trial involving recreational athletes explored the efficacy of MCT intake on medium- and high-intensity exercise performance in the presence of maltodextrin, a carbohydrate. When compared with the maltodextrin-only group, the MCT+maltodextrin group experienced significant increases in fat oxidation in the presence of both medium- and high-intensity workouts, with the greatest increase observed in the high-intensity category.  

While more research is needed before clinical conclusions can be made, MCTs may help promote athletic performance as an alternative energy source. Research also suggests they may also help support brain health, periodontal health, antioxidative status, and a healthy response to inflammation.*

By Dr. Cory Ambrose, ND, MAT and Caitlin Higgins, MS, CNS