I've got Dr. Tommy Wood back on the podcast to talk about supplementing with carbohydrates for endurance performance. I had a terrible time with maltodextrin-based sports gels back a few years ago, and I've since noticed that some of the best athletes I know do well on long rides without eating anything. But still, the studies show a clear advantage in supplementing with carbohydrates during workouts lasting longer than one hour. Luckily Tommy is here to help me understand the studies, the potential pitfalls and the biochemistry of supplementing with carbs. For the past couple of years, I've been supplementing with UCAN Superstarch during long, hard workouts and races. I think of UCAN as the training wheels that enabled me to be a better fat burner. Now I'm left wondering, is there something out there that works better? Or is there something as good but cheaper, e.g. waxy maize? Or fructose? Tommy and I intend to find out which is best for me using an oral glucose tolerance test. In the show, I mention the UCAN study, and also these two studies on waxy maize and fructose. I also said that I wasn't sure whether or not I'm ketosis. I've since measured blood ketones at 2.1 mmol/L and six green flashes on a Ketonix Sport breath meter.