2. The Angry One

On no account must you approach this individual. They are dangerous and the 'alpha' entity in the gym. They are there not just to work out but destroy everything. Records, machines, people. The grimace on their face is matched only by their determination to become the next local 10k champion or ParkRun leader. This isn't fun for them, it's their life. They will be armed with heart-rate monitors, distance measurers, isotonic hand grip dispensers. They are, to all intents and purposes, Robocop on a treadmill. You will know they're there because you will hear the heavy tramp as they sprint on the machines at 17km per hour, far drowning out your steady 3km an hour stroll. Cut them, and they bleed sparks.