The Mightier hröa ?

[Inziladun]

In terms of their spirit as both Children of Ilúvatar, Elves and Men were equals. The only difference was the destinations of those spirits upon "death".

In their bodily forms however, it seems clear that the Eldar were superior. They did not age, and were subject to no sickness. They could also be healed of wounds that would kill a Man, as Beleg showed on Amon Rûdh.

The Silmarillion puts it thus regarding physical strength:

In [the First Age] Elves and Men were of like stature and strength of body, but the Elves had greater wisdom, and skill, and beauty....

Of Men

Elsewhere it was said that the physical growth of the youths of both races was similar, but Men then obviously wore out much more quickly and aged.