There’s no concrete consensus, however, most estimates consider using optimal human conditions a maximum upper limit between 5000 and 6000 pounds (around 2500 kilograms). These conditions may include peak bone density, enhanced muscle mass, superior tendon strength, and perfected technique. Nevertheless, these conditions would most likely expose an individual to extreme risk of injury, or even death which sets this estimate as a theoretical maximum that athletes can’t realistically pursue given the dangers involved.