I used to use a Fellowes mouse pad with gel wrist rest. Stopped after my wrist started getting sore. Problem was I was resting my actual wrist on it which squashes the blood vessels and tendons and reduces blood supply to the fingers.
If you insist on using a rest, I suggest you only rest the heel of you palm on it when not moving your mouse. Same thing for keyboard rests.
Wrists do not appreciate being under pressure for extended periods.