Vitality of the Tree: Life giving on 1st turn?

Hey, it seems to not be the case but I wanted a second opinion.

World Tree Barbarian's level 3 Vitality of the Tree, Life-giving Force subsection begins with:

At the start of each of your turns while your Rage is active, you can choose another creature within 10 feet of yourself to gain Temporary Hit Points. 

That seems to mean in Round 1, if the barbarian rages and attacks his first turn, the barbarian can not also use Life-giving Force that same turn (but still gets the Vitality Surge for himself) since the rage was not active at the beginning of his turn.