There is a lot of interest in making claims for sports nutrition supplements. Who better then than endorsements by coaches involved in training athletes to high standards.
1. www.coachesinfo.com is a learning site for those who want to become accredited as a sports coach. Courses can be bought and learned on line. It also has some science based studies by various universities across the world and as an example http://www.coachesinfo.com/index.php?option=com_content&view=article&id=337:tennis-enduring&catid=95:tennis-general-articles&Itemid=173
In this article BCAA are mentioned for endurance tennis matches.
There is an obvious need for science based evidence as the EU tightens up its claims.
This is an extensive learning site which does mention other references to nutrition as part of training athletes. There are many references given.
The designers and authors of the site are www.capdm.com a UK based group who are specialists in on line learning platforms