Natural Elastic Recoil Frequency

Don't have a song for you, but in case you missed all the tweets and blog-o-shere buzz about it, have a listen to the the latest Trail Running Nation podcast, where they interview Dr. Mark Cucuzzella about natural running.  He talks a lot about running form, shoes, and all the good stuff, but the bit that caught my attention was what he says about cadence.  He says that the human body has a 'natural elastic recoil frequency' of 85-95 steps per foot per minute, or about 180 total steps.  Very interesting stuff!