Dan L wrote:
You can be very fit and fat if you eat enough - and cyclists eat a shit load. When you can't go any further on a bike it's not of your physical capabilities, it's because you've run out of energy, so it's importand you keep eating. With running, because of the increase in load you body has to carry, it will reach it's limit before you run out of energy.

And you notice the belly more on cyclists because they're dressed like the only gay in the village. Running stuff's a bit more flattering.

Based on a sample of me, I've noticed that fitness can be sports specific. When I'm fully trained up for stuff I can swim, bike and run all day but you stick me on a rowing machine and I'm fucked after half an hour - but that said, without a doubt running is harder than cycling. It's very strange you can run like that for that long but not be able to do a spin class or something with relative ease.
it never ceases to amaze me how I can cycle 60-80 miles in a day with no problem and no training yet a 50m run for the bus leaves me fucked for 10 minutes.

yet a mate of mine who does yoga, kick boxing, running and gym work every week is fucked on a bike before I'm warmed up.

fitness is surprisingly specific.

running is harder than cycling - but the TdF has got to be harder than just about every running event on the planet (just about - awaits link to an annual running race that follows the route of the trans-siberian railway)