Q for TDF enthusiasts

I was rereading Cycle Sport’s TDF issue w/rider profiles and it mentioned that Lance is 5’10 and 171. Jan, on the other hand at 6’ and when “in form” is 159.

That’s more then a subtle difference.

Jan’s always appeared to be a pretty big guy (correct me if I’m wrong); thicker and in general a larger frame then Lance. When would you say he was last 159?

The Tour weighs every single rider before the start and measures their height, lung capacity and resting heart rate among other things.

I could not find the page that shows all of this but letour.fr shows these stats for the tour riders
Jan is 1.83 meters, 73 kg
Lance is 1.77 meters, 75 kg