the impact

Some make it look effortless, but some (including colleagues and associates with running-derived injuries) do not, which is why I am not tempted to see if I could do one of these, as I've never been naturally keen on running long distances. Scampering short distances is fine, as is walking long distances (and the Skegness to Horncastle Walk was about 23 miles and could be done in just over four hours, with the proper silly walking technique).