Peak Human Stamina: John's musculature produced less fatigue toxins during physical activity than most other humans, though not to a superhuman degree. He can physically exert himself at peak capacity for approximately 1 hour before the build up of fatigue toxins in his blood begins to impair him.
Peak Human Durability: While not superhuman, his body is as durable as a normal human's could be. While still subject to all human physical vulnerabilities, he is more resistant to them than most other humans.
Peak Human Agility: John's agility was also increased to a level that, while not superhuman, is superior to that of any Olympic athlete that has ever competed.
Peak Human Reflexes: John's reflexes were increased to similar levels and are superior to that of any Olympic athlete.