Ryan Hall's stride length is 6' 10" and his mile pace is 4:46. This spring, he ran the fastest marathon ever by an American: 2:04.58.
And yet from the photo above, you can see that his feet still land directly underneath his body -- the way they're supposed to. Clearly, speed doesn't have to come at the cost of form.
See what I mean?
Runner's World recently ran a feature on Hall's running form, noting that his technique is much more sound than many other top-caliber marathoners, including Meb Keflezighi, winner of the 2009 New York City Marathon.
It's good stuff. Check it out.