Steroid users form a tight-knit community. Powerlifters tell each other what's good and what's not. "The community weeds out the shoddy stuff", says Alexander
"Steroids are an amplifier. If you've already got a bit of a temper, you'll have more of one," says Dave.
Alexander trains his deadlift, the most taxing lift on the central nervous system. His strength means he uses 50-kilogram plates instead of the standard 20 kilogram.
Jack is the co-owner and founder of Elevate Fitness, a martial arts and powerlifting gym in Richmond, London
Dave's home is stacked with his bodybuilding trophies and powerlifting medals.
Dave catches his breath in between sets of accessories after training his main lifts - squat, bench and deadlift.
Alexander hangs on the squat rack, catching his breath after his sets. He trains out of his self-made garage gym, not bothered about the cold winter winds.