Physical conditioning should be part of the lifestyle of anyone concerned with being prepared/equipped to survive.
The best advice on this thread so far... If lugging around 19lb on an easy day hike exhausts you so much you nearly pass out you should forget about survival gear and get in shape first.
It's funny that so many people obsess with the ultimate survival gear when they lack even the basic physical prerequisites. How come there are so many threads about survival knives, climbing harness, BOBs and whatnot but virtually no discussion on physical training and the like?