All the naiive on LRC say it is the shoes that are causing marathon and athletic records to drop left and right. But it is not the shoes, it is new classes of PEDs as evidenced by what has been happening in pro cycling for the last 5 years where they don't wear Nike shoes but are seeing power and climbing records that makes EPO fueled Lance look like a Sunday club rider. Whereas Lance has threshold power of 6-6.2 watts/kg, the top pros are now going 6.8 watts/kg and we are not even in Tour de France season yet.