Life-Up Heart

The Life-Up Heart is a power-up item that appears in Super Mario Odyssey. It is the only "traditional" power-up in the game, as Mario's forms are mostly taken through Cappy's Capture ability. It serves the same function as the Life Mushroom from Super Mario Galaxy and Super Mario Galaxy 2: when collected, it increases Mario's maximum health by three; however, if his health is depleted back down to three, he will lose the three extra pieces of health. Life-Up Hearts can be purchased from the Crazy Cap store for 50 regular coins, though one can be found inside a ? Block in New Donk City, before the Mecha Wiggler boss fight.

Crazy Cap description
"This heart-shaped item raises your maximum life value."