Good article
I agree that swimming a 100m is much more strenuous than running a 100m.

You how ever get running and running...for instance running the marathon, needs a high level of fitness and endurance, not much technique. It also put a lot of strain on your body eg. the knees.

Then there is my favorite sport to watch (not take part) where fitness, endurance, technique, strength are all of utmost importance, and if you make a mistake you pay with pain!!!!!