Janni Rush and Vital strike?

[Petrus222]

Janni Rush
" make an unarmed strike against the designated opponent, a hit allows you to roll the unarmed strike's damage dice twice and add the results together before adding modifiers..."

Vital Strike
"Roll the weapon's damage dice for the attack twice and add the results together before adding bonuses from Strength, weapon abilities (such as flaming), precision based damage, and other damage bonuses."

So if you used both feats together, would this double the dice twice for 4dX (where dX is that unarmed damage dice) or just add the dice again for a total of 3dX?

[Cao Phen]

Janni Rush is used during a part of a charge. You can not Vital Strike while charging. Hope this helps.

[Petrus222]

I didn't realize that. Thanks!

(Makes you kind of wonder why bother with Vital strike at all then.)

[James Risner]

You would need to successfully jump, and it isn't clear to me a "noop" jump would count.