IS does absolutely nothing for improving Sports/Action shots, it is really only when you're hand holding the camera taking a picture of the tennis player when they're about to serve or receiving a trophy etc., namely when they're not moving fast.
I had an EF 70-200mmf/4L IS USM lens and it used to triple my battery usage (so batteries last 200-300 shots and not 800-900 shots)
Lastly, if you'll be using a monopod or tripod, then it is always recommended to switch OFF IS (some modern lenses will automatically do this anyway once they sense they are tripod-mounted).