Swimming equivalent to marathon run? Ultra run?

tortugatortuga Senior Member
edited April 2014 in General Discussion
Marathon swim equivalent to running a 26.2? 50 miler? 100 miler? My guess would be 10K, 10 mile, 20 mile respectively. Any ideas?


  • NiekNiek Heiloo, NetherlandsCharter Member
    For the 2008 Olympics the FINA needed a distance.

    They took the 10 km because the duration was almost equal to the 42,195 km marathon run with swimming then on a average of 2:10 hours for the 10 km and the runners on an average of 2:05h.
    Around that time they also started to call the 10 km a Marathon Swim and the bigger swims a Grand Prix
    Before that time the bigger distances were called a marathon and most East-European countries still call every openwater swim a marathon.

    Today the elite swim the 10 km all around 1:52h where the elite runners are still around the 2:00h.

    http://openwaterswimming.eu - Cold, wind, waves, sunburn, currents, jellyfish and flotsam! Hop in and join the fun!

  • IronMikeIronMike Moscow, RussiaCharter Member
    I swear we talked about this somewhere in these forums. Can't remember what we came up with, but I think you're close. Had to do with what the elites do in those distances, time-wise, then what distance our elite marathon swimmers do in the same time, rounded to a nice number.

    For ease with my triathletes, I multiply by 4. Or divide, depending which way I go. I tell them I'm doing a 10-miler, I tell them that's equivalent to them running 40 miles.
  • Leonard_JansenLeonard_Jansen Charter Member
    tortuga said:

    Marathon swim equivalent to running a 26.2? 50 miler? 100 miler? My guess would be 10K, 10 mile, 20 mile respectively. Any ideas?

    Actually having done all these, I would say @IronMike's "factor of 4" rule is pretty close. However, there is a wear and tear to running/walking races that you don't get in swimming. At the same time, swimming races have extended periods of total isolation that you don't get in running/walking. Throw in cold water, lampreys, men in grey suits, seasickness, drunks in boats and waves and maybe swimming sounds tougher. Throw in altitude sickness, getting lost, snakes, drunks in cars and bears and maybe running/walking sounds tougher. (I was once in a race where a guy fell over a bear.)

    But it's all good clean fun for kids.


    “Moderation is a fatal thing. Nothing succeeds like excess.” - Oscar Wilde

  • Equivalent for whom? I have only briefly considered running a marathon and only if it was at the end of an Iron Man race. But somehow swimming got in the way of that goal. If we use the ratios that Iron man uses it is a 12:1 ratio which is ridiculous. I think IronMan needs to up the swim by a factor of 3 (off topic comment). Once I complete a 28 miler I may revisit the run a marathon goal. I don't want to ever have to admit to having run farther than I have ever swum.

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