I found these videos where a guy takes a look at the Ironman Kona Triathlon competitors and analyzes their running style, putting them into one of two groups:
Gazelles have a lot of travel through the air as they run because at push off with the rear foot, they push up and get a little more air than Gliders do. They don’t have as fast a turnover as gliders.
Gliders have less travel through the air – nearly a foot less in some cases, and yet it looks like they are using less energy to move forward. Hard to say because the Gazelles are getting more air.
There are amazing Ironman marathon runners of both styles, among the women and men, so, basically it comes down to which style fits you. However, for shorter races, 5K, 15K where you want to go under 6 minute miles, Todd Kenyon says you must run like a Gazelle because your stride turnover cannot get you moving that fast without the extra foot of air travel you get, versus the Gliding style.
Have a look at the videos, they’re remarkably well done. Thanks Todd. Cheers!
1st Video – Gazelle Runners vs. Gliders, a comparison of running styles
2nd Video – Gazelle Runners vs. Gliders