The Nike Invincible 3 mostly sticks to the blueprint of the first two versions of the shoe, with its star feature being the ZoomX cushioning used in the midsole. This is the same soft and springy foam used in Nike’s top racing shoes, the Vaporfly and Alphafly, but in the Invincible it’s there to create a comfortable and fun ride for easy training runs, rather than to help propel you to PRs.
One concern that has surrounded the Invincible since the first edition is that this ZoomX midsole is not all that stable, especially without the carbon plate you have running through it in the Vaporfly and Alphafly. With that in mind Nike took steps to make the Invincible 3 more stable by adjusting the upper, midsole and heel counter on the shoe.
