On the Supposed Fragility of Elves
Elves are often described as delicate, which is largely an aesthetic judgement mistaken for anatomy. Their bodies are comparatively slender, their musculature less bulky than that of Humans of similar height, and their bones somewhat lighter. They therefore appear fragile beside Dwarves or Aesir. They are not.
Elven connective tissue is extraordinarily resilient. Joint flexibility is high, tendon injury is relatively uncommon, and their ability to recover from strain often exceeds that of Humans. They are less well suited to brute-force labour but remarkably well suited to endurance, balance, and repetitive motion. The stereotype likely persists because Human observers equate visible muscle with physical capability. A heavily built Human labourer looks strong; an Elf carrying the same load for six hours without complaint looks decorative until one notices that he is still carrying it.
This does not mean Elves are physically superior in every respect. Their lighter skeletons are less tolerant of certain crushing injuries, and they do not generate the explosive force of Dwarves or Aesir. A contest involving lifting a stone once will usually favour the Dwarf. A contest involving carrying it over a mountain may become more interesting.