There are some things you can watch for.
First of all, f1 drivers have to be hugely concerned with their nutricition. Studies found out that an average body only can transform 18-26% of the taken kcal into effective labor. To give a slight insight in this: alonso uses technogym fitness apparatus, the ones my gym also has. I know for a fact he uses the arm bicycle, a very usefull device to create the necessary stamina to keep turning a whole race long; even with powersteering that is a cumbersome task. Now, I really dont know about his resistance level and the time he does on it, but if I take mine, lvl 12 30 minutes, I have an output of more or less 275 kcal. That is about 1100-1325 kcal of nutrition you need. A f1 driver will probably consume more energie then that in the same half hour due strain on neck muscles and the high amount of focus that is needed. Now a normal man who does office labor (and not physical labor) needs roughly 2000 kcal a day. I would expect that a f1 driver on race day will need 4000 kcal for the race alone.
(More to come)