Any thoughts on whether Keto/High fat diets would be beneficial when running ultra marathons (100+ miles races)
My brother runs them as has complained that digestion i.e frequent bathroom breaks has been an issue when running longer races. He suspects that the fast acting carbs, gels, or just the constant refueling may be the issue and has been thinking if a higher fat diet or even going keto may help.
Have you even bothered to do a simple internet search on low carb for endurance performance? Names like Phinney, Volek, may jump out out at you because they have been publishing scientific data on this topic for years. If you genuinely want to help your brother spend a dollar or two on evidence-based books rather than looking for quick and lazy answers on a forum.
I am aware of that study. I know Jacob Wilson’s credibility has come into question recently but still believe there is some validity around the idea of rapid fat regain when ‘large’ amounts of carbohydrates are introduced to ketogenic dieters. This is why I am not in favour of cyclical ketogenic diets or so-called ‘refeeds’ such as the kind Lyle McDonald advocates following aggressive diets.