Yes, it seems that one exercise does not translate well to another exercise. If you're having trouble getting up to speed on running you might try the "none to run" program. It's a very logical way to build your running legs. I have my own translation of the program: I do about 10 miles a week with a 30 pound pack. I jog about half of that and mix it up with a fast walk. I've found my goal for hiking training / exercise is to maintain a 15 minute mile pace with a 30 pound pack for about 3 miles. I'm usually toast after doing 3 miles in 45 minutes with a 30 pound pack around the farm but once you go back to a normal 2-2.5 mph hiking pace with a 30-40 pound pack, or simply doing a run without a pack, it seems pretty easy. Main thing I've found is do not train every day. Get on an every other day program and you're less likely to cause injury.