[evandev]

Speaking from my personal experience to counter this, I run in the mornings up to 1 hour on an empty stomach. While I don't follow one diet, a larger portion of my food is carb based.

I follow TFTNA (Training for the New Alpinism) and Uphill Athlete (Steve/Scott's new book) training regiments that Parent mentions.

They do talk about retooling your body to use fat reserves more than carbs. While I'm sure the evidence shows that keto diet might make this switch faster and easier, someone on a non-keto diet (carb based) can also do this.

[crikli]

Haven't read Uphill Athlete yet...I think it ships in a few days. Really looking forward to it and to going to see Scott/Steve speak in Denver.

[evandev]

I don't think I'll be able to make any of their talks because the nearest city is a bit away, but I do frequent their forums/site which has an incredible trove of information.

https://www.uphillathlete.com/

[crikli]

Agreed! I love that Scott is so active on there. Those guys are legit.

My other very favorite resource is Shawn Bearden's Science of Ultra podcast, which is where I learned of the research paper I linked in my first post. Here's the one on fat adaptation: https://www.scienceofultra.com/podcasts/19 . He has lots of pretty hardcore exercise scientists and researchers on. It's one of my favorite things to listen to while grinding up a hill. :)