I took the fixie up to the hills of the East County, and rode for about 4 hours, climbing about 1300m (4270 ft) over 90 km (56 miles). My Strava recording for the ride says I burned 2400 calories, which might be close, since it’s easy to compute the work required for climbs.
I made it out to the Golden Acorn Casino, which looked pretty empty @ 10am. You’ll look out-of-place on a fixie in a rest stop that only cars can get to. Most people aren’t very active, and you’re really going against the trend to end up in the middle-of-nowhere, off the freeway, on a track racing bike with no gears.
I’m eating less on these endurance rides, now that I know what my body needs. You’ll burn fat on these rides whether you’re on a ketogenic diet or not.