No way you can keep that kind of mass long term and live long. Some have tried and all have failed. Nasser, Kovac... Your heart and lungs are pretty much fixed. They don't get that much stronger as an organ. You can improve your cardiovascular makeup so that your heart doesn't have to work as hard (larger veins, arteries, capillaries) and the same with the lungs. You can improve air flow and oxygen transfer. But you reach a tipping point when your body is carrying so much more muscle than your body was meant to and the burden to your heart and lungs, especially your heart, begins to take it's toll. There is a constant metabolic cost to muscle even when at rest.
