How Kratos Survived In God Of War 3

In the novelization it is stated that 50 years has passed since god of war 3 although kratos looks more like 45 55 years old not 90 ish years old.
How kratos survived in god of war 3. This could be attributed to his immortality. We see in the first fight against baldur that kratos has a regenerative power. We see in the first fight against baldur that kratos has a regenerative power. It s also worth noting that nearly fatal wound kratos gave himself at the end of the third game is also a product of one of his most selfless acts.
Kratos is the protagonist of the god of war series. 25 kratos survived his wound from god of war 3. Born in sparta kratos was a respected soldier and general up until he lost his wife and daughter when he killed them albeit by accident under ares command earning him the nickname of the ghost of sparta after which he renounced his. For god of war on the playstation 4 a gamefaqs message board topic titled do they ever explain how kratos survived.
This could be attributed to his immortality.