HOW FAST CAN I DO THE FAN DANCE AT 72YRS OLD?

The Fan Dance is a 14 mile route in the Brecon Beacons used by the UK Special Forces as a selection exercise. They have to complete the route in 4hrs 10mins or less carrying a full load including all the equipment they would need to be selfsustaining in battle. I wasn't carrying anything like that - or had any expectation I could do it in the alloted time - but what could I do?