SUMMARY

FAT

Fat is the main fuel you burn at rest and during exercise at less than 60 percent of VO₂max.

Most of the fat you ingest in a pre-exercise meal isn’t utilized for fuel in muscle during the subsequent exercise, at least during exercise lasting a couple of hours or less.

Eating loads of fat (especially long-chain triglycerides) in a single sitting slows stomach emptying in comparison to eating other macronutrients.

Although chronic high-fat diets can boost your ability to burn fat during exercise, they also interfere with your ability to burn carbohydrate, especially at high intensities.

High-fat diets may have positive (or at least equivalent) effects on performance for ultraendurance competitions that last a few hours or longer.

High-fat diets are more likely to hinder performance in competitions that rely heavily on sustained carbohydrate burning (75 percent of VO₂max or higher).

In comparison to high-carbohydrate, fiber-rich diets, high-fat diets reduce stool weight, bowel movement frequency, and flatulence and may unfavorably alter the gut microbiome.

Ingesting MCTs hasn’t been shown to enhance performance and can cause nausea, abdominal cramping, and diarrhea during exercise if they’re ingested in large dosages (greater than 20–30 grams).