When I arrived at Cusco they gave me oxygen, the trek was a lot harder than I expected, it was very difficult to do anything and breathe. But everyone who started the trail finished at Machu Picchu it was the first time that had happened on a trek organized by Discover Adventure, they would normally expect four people to drop out on the way.
It was the most amazing thing I have ever done, I would recommend it to anyone but I would also say that what ever training you do it can never be enough. The guides told us that finishing the trek was 90% determination and we were all very determined.
The views were spectacular, we saw several humming birds. Most of the time we were so high up that we looked down on mountains that are bigger than any hear.