Four days off running, a 15-mile run on the fifth day, no problem with the hip: I’m declaring myself fit. Hence the reward: chocolate Hobnobs, the king of biscuits. A 15-mile run at a little over seven-minute mile pace burns 1,664 calories, apparently. I find that figure hard to believe, but by that reckoning a gut-busting 18 Hobnobs – each laden with 93 calories – could be consumed without any impact on health. Alas, it doesn’t work like that. Still, five or six or seven won’t hurt.