How can I then edit my animation for make shake hands while running until frame 90 if I can’t see the original frames (in graph editor) of my animation for use the keyframes extrapolation ? I then choose to make animation of running take more frames, like to 90 so with NLA I keyframed the ending position desired for my model at frame 90, but if I play my animation the model is running perfectly until frame 54 then offcurse animation stop play after that frames. Now I have a curiosity instead, after I used the NLA on my model I could not see anymore the framekeys for the other bones of my model (the original ones) because let’s say I have an animation of the hands shaking while running from frame 1 to frame 54.

Then I selected the root bone and translated to Y axis it until I pass the camera position and keyframed position of it matching rhe final frame of the animation, then selected the first frame of root bone on the dope sheet for Z position and set the interpolation mode to linear and that’s made the run animation go faster !! Not sure if it was the right way or not As Gordon suggest me I then went on NLA and keyframed the pos of my root bone at the begin of the original animation frame.

So I put near the end of the animation my camera.

Thank you so much for the input you provided me, so for testing I just used a character from Mixamo, applied a running animation (not in place) and downloaded it as FBX, then imported to my scene.

Mixamo blender animation