Root Animation & character movement speed

In may top down example I have root animation (roll). At the and of the animation the pose is standing so I assume it means that the velocity of character is 0. But what I want to achieve is that after that animation if I still holding left mouse button I would like to keep (have) max walking speed. Because right now the character stops and going to max walk slowly.

Is it problem of animation itself ? Or how I can actually keep character running without any interruption after root animation.

Thanks for help.