GNC Ambassador Lee demonstrates 'how to...Chin Up' at Zone gym in a series of 'How to...' videos. For the latest in Sports Nutrition check out: http://www.gnc.co.uk/ Check out Lee's Fitness & Nutrition blog: http://gncukblog.wordpress.com/ Like us on Facebook: http://www.facebook.com/gncuk Follow us on Twitter: https://twitter.com/gncuk #TeamGNC