John Bishop takes the word 'triathlon' to new heights in an extraordinary physical and mental challenge for Sport Relief. John cycles, rows and runs from Paris to London, accompanied by celebrity supporters like Davina McCall, Chris Moyles, Freddie Flintoff, Dermot O'Leary and Frank Skinner. This incredible challenge pushes John to his limits, and the only way he keeps going is remembering why he is doing it in the first place - to raise money for Sport Relief. John visits Sierra Leone to see the incredible work done by Sport Relief, and learns how vaccines that we all take for granted in the UK can save lives. This intimate and honest documentary captures the laughter and the tears as John battles with intense pain and exhaustion in his determination to succeed.

• Claudia Winkleman