The heart rates of the elite and club runners are evenly matched during the marathon with the maximum output coming at around 24 miles.

With the adrenaline gone and the body reaching its physical limit, the mental fatigue also begins to take its toll but the club runner can draw on an additional boost.

Fagan says: "With six miles to go I felt tired but you get a lift as you pass lots and lots of people making the last two miles really exciting.

"On the finishing line you just feel like bursting into tears, I said to my husband it's like childbirth because it is agony but at the end of it, it is so exhilarating."