Are there genetic/anatomical/age limits on how flexible a person can become? I've poked around on the Internet and PubMed.gov about this topic and can't find anything compelling.
I've been doing the 3 stretch series videos for 9 months now and have become significantly more flexible. I'm very happy with my results. However, I wonder whether if an inflexible, older person devoted themselves to a well-thought out flexibility training program for, say, 2 to 5 years could they become as flexible as someone like Kira Nguyen (in the videos)? Or, is there something about her make-up that permits her to attain an extreme (in a good sense) level of flexibility?