average speed of a marathon swimmer compared to a marathon runner
The MSF has just posted statistics on the Facebook page about how fast an average marathon swimmer is. The speed is quoted as 3.2 kph at 10 km for amateurs. This translate to about 3:07:30 for the whole race.
As a 10 km swim is comparable to a full marathon, This time / speed is just unbelievable for an "average" swimmer. If you can run a 3:10 or 3:20 marathon, I think you are already better than the VAST majority of runners! So I find out how fast an average runner can run a marathon. And, in a news article, it is quoted as 3:52:35 in 1986 and 4:32:49 now, which shows that as marathons get popular the world gets slower, and I think it is normal.
However, what makes me really shocked is that the vast difference between the average speed of swimmers and runners and it really makes my self-esteem low. I am training for marathon run and marathon swim at the same time and targeting the same time in both marathon run and marathon swim. If I can complete my marathon run in that time, it will put me in the upper half of the runner population. However, even if I can swim my 10 km at that time, I am nowhere near an "average" swimmer, so it gives the perception that I'm a bad swimmer.
What are the reason that, a 10 km swim and marathon run are done in similar time in world-class athletes, but not by an average amateur? Why are amateur swimmer "faster" than amateur runner by so much when the elites are doing them in similar time? (unfortunately triathlons with both a marathon swim and a marathon run haven't gone mainstream yet - most races are biased to the bike then the run and underweight the swim, otherwise we can get more useful insights if the swim and run are done by the same population)