[QUOTE=JohnK;498068]I am with Iain R on this Genes have Damn all to do with ability to run fast or slow. In fact there are far to many factors, such as distance, time of day, mental application, diet muscular/skeletal makeup, Lifestyle, both living and working environment terrain etc etc etc, so to even tryand begin to isolate a single one is futile IMO.

There is evidence starting to appear that genes may play a part in how much a person can improve/achieve. There was a Horizon programme on a few months back that looked into the various aspects of exercise and it included a study of increases in VO2 max after exercise. The results seem to suggest that up to 15% of the population are "super-responders" who achieve high increases in VO2 max whereas up to 20% of the population show very little improvement (with the rest obviously being somwhere in the middle). While studies like this need repeating by other research groups to ensure that as many contributing factors (such as diet etc) are being normalised acuurately the evidence does seem to be heading that way for certain physiological parameters that aid things like running. Some links below to some of the reports and research.

http://www.bbc.co.uk/news/health-17177251

http://www.pbrc.edu/heritage/index.html

http://jap.physiology.org/content/10...e2=tf_ipsecsha