Strength

From the OblivioWiki – your guide to everything Oblivion

Strength is a character attribute that influences the amount of damage a character inflicts through melee weapons. It also determines a character's fatigue (one point per strength) and encumbrance level (five points per strength), which is the total amount of weight he or she can carry.

Strength governs the skills Blunt, Blade, and Hand to Hand. Strength over 100 will still increase the fatigue and total amount of weight a character can carry, but not the melee damage.