As far as I know, time dilation has little effect on Mars compared to Earth, and I'm not asking with that in mind.
I'm rather asking if the low surface gravity (38% of Earth's) could allow humans to live longer because the lower gravity would strain the body less.
I read a study (I'll try to search for the ref.) that if you over-train frequently you could potentially decrease your lifespan, so wouldn't it make sense that if your body had much less stress applied to it (gravity) you could survive longer? Wouldn't the lower gravity also mean that you would have to train more in order to not degrade your muscles too much?
PS: Could it be that native Martians (if humans are ever born there) would be unable to ever come to earth since their bodies would be adjusted to the martian gravity? Maybe if they exercised a lot?