(From left) Britain&#39;s Jessica Ennis, Belgium&#39;s Sara Aerts and Russia&#39;s Tatyana Chernova compete in the women&#39;s heptathlon 100m hurdles heats at the athletics event during the London 2012 Olympic Games. Ennis made a flying start to the heptathlon as the London Games athletics programme got under way in front of a vocal, 80,000-capacity Olympic Stadium crowd