In reply to john arran:
ridiculous? What the high jump, long jump and pole vault aren't, let along throwing the hammer. You may think its ridiculous in this country, but its a massive sport in rest of Europe.
Have you ever heard of A Centurion?
http://www.centurions1911.org.uk/history-of-the-centurions.html
A Centurion is one who, as an amateur, who has walked in competition in Great Britain 100 miles within 24 hours
IF you can do that (not many people can) you can then enter the Paris to Colmar race, 445km (276.51Miles) its done none stop, apart from food & clothing change stops.
http://en.wikipedia.org/wiki/Paris-Colmar
That puts your top 4 suggestions into perspective.
As for the 'mincing', that's the hip rotation, because you have to have one foot on the ground at all times, other wise its classed as running (lifting) Which is better for your joints than running because you're not landing on them, you're placing them.
See the rules to race walking
http://www.centurions1911.org.uk/race-walking-rules.html
here's the world record stats
http://en.wikipedia.org/wiki/Racewalking
Post edited at 10:30