Davina McCall's Sport Relief challenge
14 February 2014 Last updated at 11:29 GMT
Davina McCall is expected to finish her 500-mile Sport Relief triathlon on Friday afternoon, by running a marathon.
The TV presenter started the challenge in Edinburgh on Saturday and has spent the rest of the week running, swimming and cycling to London.
McCall was joined by pal and comedian Jo Brand in Windsor ahead of her final run.