Key Takeaway
MCT oil supplementation does not consistently improve endurance performance, but may enhance fat oxidation during exercise at moderate intensities.
Summary
This systematic review examined the effects of MCT oil supplementation on endurance exercise performance and substrate utilization in healthy populations. The authors reviewed studies that measured outcomes such as time to exhaustion, time trial performance, and respiratory exchange ratio during prolonged exercise.
The evidence did not support a consistent ergogenic effect of MCT oil on endurance performance. Most studies found no significant improvement in time to exhaustion or time trial outcomes when MCTs were consumed before or during exercise. Some studies reported gastrointestinal distress at higher MCT doses, which may have offset any potential metabolic benefits.
However, several studies noted that MCT supplementation increased fat oxidation rates during moderate-intensity exercise, as indicated by lower respiratory exchange ratios. This shift toward greater fat utilization could theoretically spare glycogen stores, but this did not reliably translate into measurable performance gains. The authors suggest that MCTs may be more relevant for metabolic flexibility than for acute performance enhancement.