There isn't any. You're warping spacetime, not moving through it. From the perspective of the central pod, you're not moving.
So, that whole “inertial dampeners” thing is straight out the window? Perhaps they would still be useful (with some performance improvements) in case of an attack by aliens on our starship?
Every time the Enterprise is hit with a phaser, the bridge crew gets tossed around, or at least jostled as in “Next Generation,” and the inertial dampeners fail miserably even though they work great for warp acceleration.
Just sayin’. ;-)