It's taken some time for me to get back to this, but I wanted to let you know that I tested this during regular gameplay with a set of twins in my legacy challenge. One maxed fitness (no aspiration or long-lived trait), the other was at level 9 when aged to elder. Both died of old age at the exact same time, within 24 sim-hours of getting the message "long life coming to an end".
Both of the sims from earlier that had the long-lived trait did live the extra 17/18 days past the "long life coming to an end" message. I did get the "dangerously tired" moodlet for the one that remained in the athlete career, when he went for a jog. I thought the long-lived trait was supposed to guard against that.
So, I can confirm that in my game the maxed fitness does not add any bonus days to the sim's life. The long-lived trait does add the appropriate number of bonus days, but does not appear to guard against physical activity / death by exhaustion.
I can't comment on the number of days since I'm no longer playing the household with the sim who completed the aspiration, but I can confirm that he constantly got the dangerously tired moodlet when he became an elder and I didn't remember that happening in the past (though granted I don't play with elders that often). It got so that I had to take all the fitness equipment out of the house because my active elder kept using it and would always come off with that moodlet (I was playing the Drifter Challenge and he was one of the sims I wasn't supposed to control, though this was at least six months ago, probably a bit more).
Thanks and regards,
Jennifer
