Try it. It works.

It's fuelled me for 1000+ hours of training at this point, through iron distances and two ultraman stage races. This is gonna sound like an ad, but I've no connection to Dr. Harrison other than using the Saturday app. Fueling according to its recommendations has helped me stay consistent and injury free over the last couple years, and I've leaned out without even trying--likely in part because I don't get home absolutely starving from long efforts. Recovering better than ever.

For what it's worth, for the swim and bike, I use Skratch hydration as my "base", since I like the flavours, add table sugar and salt as needed. For the run, I prefer to drink water for whatever reason, so I use maple syrup+salt in a flask as my fuel source. Easy, portable and pretty cheap when I see companies selling gels for 7 dollars a piece!