Professor Russell Foster, an expert in body clocks, has written an article about teenagers' body clocks running slightly behind those of older people.
TES 12 January: www.tes.co.uk/article.aspx?storycode=2330060
BBC Radio 4 'Today' - 12 January 0741 am
London Metro 12 January: www.metro.co.uk/news/article.html?in_article_id=32697&in_page_id=34
Daily Mail 12 January: www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=428233&in_page_id=1770
Also Friday 12th January - BBC Radio Five Live and BBC Radio Wales
Telegraph 13 January: www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/01/13/nteens13.xml
Ireland's RTE2 FM 15 January