A Professional Cyclist's Leg

Varicose veins (which are what you see there) are not caused by cycling. He is just a cyclist who happens to have varicose veins, probably because of genetic predispositions.
In fact cycling is considered a way to prevent them from appearing (although maybe doing the Tour de France would be a bit excessive)

My varicose veins pop out but not like that. Gross.

D: bleck. Put some real pants on.

Are these a medical problem (like do they predispose you to blood clots)?

KILL IT!!! KILL IT!!! KILL IT WITH FIRE!!!!!

Great an interesting photo with no information. The worst kind of photo.

Those are varicose veins as far as I can tell and have nothing to do with cycling?

If cycling causes varicose veins why doesn't every pro cyclist have them? This is the sort of misrepresentation of causal links we see all the time in the popular media.

As a person that follows cycling very closely, I know that George has had these for a while. For whatever reason he has not had them removed. If I had to guess as the reason I would say it is because they still deliver blood and that is very very important for leg muscles. Perhaps he would lose some circulation.
But the veins haven't effected his performance as he is one of the older (in not oldest) guys in the peloton and has competed in 15 Tour de France races teing him for the record this year.

Funnel Cake anyone?

Are we sure those are vericose veins and not the fact that his brain leaked down to his calf muscle? Yech!

That can't be medically right. It almost looks like when someone tears a tendon, or like he's got a guinea worm trapped in his calf. Neither of which are actually going on, obviously--but seriously, can someone explain this?

BLEH gross!
An uncle of mine had bad varicose veins but it never looked like this and was never that compact. Just looks.... bleh.

Whenever I see a public disagreement I do my own dialectic method of discovery on it. I found an interesting discussion between a Doctor specializing in vascular diseases and a hydraulic engineer. Apparently the valves in the leg veins are failed-open which results in too much back-pressure which forces the veins down the leg. It is generally a congenital condition and not linked to cycling or other forms of exercise. However, increased vasculation could hypothetically exacerbate varicose veins.

I may be wrong on a few or all points; it is not the gospel truth as far as I know. But what I discovered.

For very long races, cyclists grow a second brain in the legs to use it as an automatic pilot.

No, consistent athletic effort does not produce this. A medical condition causes this. Ridiculous writing does not improve a blog.

I would guess that his varicose veins are more visible because he has little body fat and very well developed legs.