Jessica Ennis on balancing commercial opportunities with training

World champion Jessica Ennis says London 2012 is a 'once in a lifetime' opportunity and she says its important to get the balance between commercial activities and training right.

Ennis was speaking to BBC Sport's David Bond at the launch of the Team GB kit which has been designed by Stella McCartney and she says that looking good and having great kit can give athletes an edge.

The 26-year-old also talks about her performance in the recent World Indoor Championships saying that she learnt more from not winning.