[The Might]

This does go for most inhabitants in Middl-earth, be they Elves or other races. Still some, such as the Hobbits were quite lazy. Among the Elves we can't be sure how much exercise they got, but I suppose they stayed fit. Still, in some cases such as Rivendell the Elves might not have had the possibility to get so much work out as they might have wanted.
I wonder no if lembas makes you fat...