I was eating mainly Keto prior to the cycling season, (less than 20g carb) but after starting to ride had to start including carbs, at about 20% of daily cals. I found flat riding at low intensities no problem, but I'd be a complete wreck on any sort of climb. Even small climbs were slow going and exhausting.
From my experience, if you can keep your heartrate below I'd say 70-75% at all times, keto is easily manageable. Above this, your performance will be crap, and you'll exhaust quickly which you'll feel for the rest of the day..recovery seems slow.
I read base building for cyclists last week, and in the book he recommends going to 45% daily calories from carbs, so I've been trying this. Although great for performance (87km ride 2 days into diet, avg 26.8km/hr but kept it low-ish intensity) it doesn't appear to have done much for weight/body composition over the last week, and in fact I'm up 3lbs. I'm also noticing I'm sweating and am tired a lot...I feel very full/bloated, and frankly, dumb...like my brain isn't turning on. But at the same time muscle fatigue seems to be much less, I can definitely ride longer than at 20% carbs.
I'm going to dial back the carbs to maybe 25-35% and see how that goes.
Matt
Last edited by awesomeame; 06-19-17 at 07:21 AM.