Swimming vs Running - Aerobic advantage to either?

[Nightshade]

Hey folks, I just have a quick question for any of you (but naturally, especially Mr. Kurz). Do any of you see any inherant advantage to aerobic fitness in either swimming or running as compared to the other? I need to get my aerobic up to speed, but personally I can't stand running. I'll do it if I absolutely must, but I'd much rather swim. Should I be doing one or the other?

-Shawn

[Thomas Kurz]

Aerobic fitness for what? If for running, then running is best. If for swimming, then you have to swim a lot because of training specificity. Gains in maximal oxygen uptake from swimming do not transfer to running performance. Transfer of gains in running to swimming is not too good either--the best long-distance runners are not the best long-distance swimmers.

It is easier to develop general aerobic fitness (cardiovascular fitness) by running than by swimming. Perceived exertion is greater when swimming than when running at the same heart rate. This has to do with less gravity stress in water (lower heart rate) and with drag resistance (more perceived effort). Runners tend to have greater maximal oxygen uptake than swimmers and cross-country skiers tend to have the greatest maximal oxygen uptake of all athletes.

The bottom line: It is better to swim than do nothing. As for applying of the cardiovascular fitness to activities other than running or swimming, a good swimmer might do better than a bad runner.