HOW TO SPOT ONE: They’ve been running marathons since the ’50s, and although they’re fitter than a cheetah, you wouldn’t know it from their emaciated body, which looks like it can barely hold up the miniscule shorts, tatty vest, threadbare headband and inexplicable gloves that comprise the Hardcore Grizzled Veteran’s uniform.

Their gait makes them look as if they’re drunk and fighting off imaginary ghosts

The Hardcore Grizzled Veteran moves with a bizarre, hypnotic gait that makes them look as if they’re drunk and fighting off imaginary ghosts. This running style was beaten into them by a psychotic PE master during hellish cross-country lessons at a bleak Norfolk boarding school, and although it’s intrinsically linked to some deeply traumatic childhood memories, it has earned them 12 sub-three-hour marathons, sooo… yeah. Swings and roundabouts.

HOW TO DRIVE THEM MENTAL: Suggest they upgrade their trainers (in use since 1998, held together with masking tape, barely 3mm of sole left).