Britain's Prime Minister Tony Blair (L) and Health Minister Caroline Flint (C) talk to children taking part in the Y-Active Children's Programme, at the Central Young Men's Christian Association (YMCA), in central London, during a visit to promote exercise in society, April 25, 2006. A study released by Cambridge University has shown that making small changes to your lifestyle can have a significant impact on how long you will live. REUTERS/Stephen Hird