There absolutely are PEDs that increase your maximum ability when it comes to endurance sports, like EPO. A reporter tried microdosing EPO (https://www.bbc.com/

There absolutely are PEDs that increase your maximum ability when it comes to endurance sports, like EPO. A reporter tried microdosing EPO (https://www.bbc.com/news/uk-scotland-32983932 https://www.bbc.com/news/uk-scotland-32983932) and experienced a 7% increase in maximum performance in 7 weeks.