I've found that as long as your exposure time is 1/1000 or better (I heard that 1/500 is enough to stop motion, but I dunno) you should be a-ok with capturing hella abrupt shit. With my D40 I use ISO 200 whenever possible to lower the graininess a bit.
If you really want to play it safe, and your camera supports it, try setting it to either use manual settings with an automatic ISO selection (so a 1/1000 shutter speed in a shadowy area would wind up giving you ISO 800 and ISO 200 in broad daylight, or whatever) or using an aperture-priority program (which is marked with an "A" on both of my Nikons as well as my dad's Sony CyberShot) to help maintain a high shutter speed while achieving fairly consistent results.