Iwan Thomas wishes you luck.
'My main bit of advice would be smile and enjoy it.'
'Remember – whilst you are running, you are running for a fantastic charity. So from me, Iwan Thomas, have an awesome race, enjoy it and believe me, all of Team Macmillan will be behind you. Have a great run.'
Head back to Iwan's videos and get some more preparation tips for your run.
Are you ready to take on a running challenge for Macmillan? We've got running events to suit everyone.