You need to be fit and fit in the right places! The summit day involves around 12 hours of almost constant exertion at high altitude. Whilst this is a generally tiring day there are also specific demands placed on your cardio-vascular system and leg muscles. This is best trained for by going hill / mountain walking or mountaineering. Working out in a gym is a lot better than nothing but is not a replacement for the real thing. The physical challenges of climbing Mont Blanc are often widely under estimated resulting in a lot of folk ‘running out of steam’ and having to turn around on the mountain. It is not uncommon for even very fit people like marathon runners to describe the summit day as the hardest thing they have ever done. Don’t be put off if you think you are ‘more of a tortoise than a hare!’. It is never necessary to go very fast on the mountain, more just to be able to keep moving for about an hour and a half at a time (before having a very brief drink / snack stop). It is hard to get a feel for the way the high altitude will effect you without actually trying it but be aware that it is extremely important to not get exhausted on the climb and completely run out of steam on the descent. So, in addition to a high level of general fitness, stamina and determination are also required to climb the mountain with some style and a decent safety margin.
