Thanks to everyone who participated in the running workshop today at Get Built! Everyone improved their stride quite a lot. If you have any questions about run form feel free to post them to comments or e-mail me at email@example.com.
Mike requested a video comparison of sprinters vs. distance runners. Here goes:
First a video of Usain Bolt winning the 200m sprint at beijing in 2008. Be sure to watch the slow motion after 1:13. Watch his feet land directly under his center of mass until he crosses the finish, he keeps an upright torso, and has a high cadence. As he crosses the finnish line, watch how he decellerates by landing in front of his center of mass.
Next a video of elite marathon runners in the 2008 Boston Marathon. Commentary gives pretty good analysis of their strides. The only thing I disagree with is the way the commentator describes the runners driving and extending their trailing legs(*run-geek note below). I just think this puts a detrimental cue in the runner's mind. I find it more helpful for most folks to think about pulling the rear foot off the ground quickly. This helps maintain a high cadence. His description of landing under the center of mass, minimal vertical bouncing, and upright posture is spot-on.
Bonus points if you spotted the lead runner land with a slight heel strike going into the turn. The take-home point: no one has perfect form all the time, so don't beat yourself up about having perfect form right away. We can all improve with attention and practice.
Now go back to the first video and look at Bolt near the finish again. The basic form is the same as the marathon runners. You'll probably need a protractor to see any difference between their body angles. Note that Bolt's heel is almost touching his butt as he swings his leg forward. The marathon runners aren't pulling their feet quite as high, but it's not a drastic difference. Also, the sprinters are all driving their arms much farther down than the long-distance runners. (**see run-geek note #2 below for more).
UPDATE: Here's a great link for anyone considering barefoot running or wearing Vibram FiveFingers!
*run geek notes: Feel free to skip over these unless you're really interested.
1- There is definitely a quick, strong hip & knee extension extension in the trailing leg. The hip & knee extension sets up the stretch-shortening cycle in the calf. When the calf contracts, the center of mass is either directly above or only slightly in front of the foot. The combination of the hip & knee extensions with the calf contraction is mostly vertical. But thinking about driving the leg back, tends to slow an athlete's cadence and make them heel-strike out front. Thinking about driving the leg down into the ground doesn't help either - it tends to make the athlete's torso bounce way too much and wastes energy. The cue the Pose coaches seem to like the best is to focus on pulling the foot up quickly. It minimizes the athlete's ground contact time, and preserves forward lean and a smooth, fast cadence.
2- Arm and leg drive are linked, physically and psychologically. Right out of the blocks, the sprinters need as much explosive hip & knee extension as possible to accellerate quickly. This is facilitated by a coordinated vigorous arm drive. It balances the violent twisting motions of the lower body to keep the athlete on a forward path. By the time the sprinters near the finish they are at cruising speed, their torsos are basically upright, and their legs are no longer driving them forward as much. Near the finish, they could do without the extended elbows, but it probably makes them feel fast, and there is no reason to worry about the minimal energy cost of some extra arm swing in a sprint.