So basically what I mean by Smooth Running Transitions is You start from normal walk and after some seconds you’re getting sprint animation and more speed
Something like Sonic The Hedgehog
Have you looked at animation blueprints examples and Blendspace 1D animations? It explains very clearly how to do this.
Here is an example:
You can use Blend Spaces for that.
Basically you have a walking and a running/sprinting animation sequence.
Create a BlendSpace with an axis for the speed value of your character ( In the anim bp you would have to set that variable each frame the anim blueprint gets updated ).
From the asset browser drag the anim sequence for walking onto the axis at the speed value where you want walking and the sprint anim sequence at the speed value where you want sprinting.