GADGET UPDATE: I mentioned that I like this heart monitor for exercise, but my cousin-in-law Brad Rubenstein, who’s visiting, says that he has this far-more-sophisticated gadget and that it works: “You’ll do the run just to see the graph.” Well, maybe. He’s more serious about fitness — and gadgets — than I am, since he runs marathons and works in high tech.

UPDATE: Reader Mark Hoover emails with a reference to this frightening device: the Garmin Forerunner 301 GPS with Heart Rate Monitor.

Forget that FitSense rig. It’s great, but for the ultimate, you want the Garmin ForeRunner 301. Talk about incentive to run! You’re not only looking at a graph of your workout, you’re looking at a map. In fact, you can overlay the map created during your workout onto free downloadable high-res satellite photos (from the Terra server) and literally trace your route.

I use mine for endurance inline skating. To a technically oriented person, having such a richness of performance statistics available allows performance tuning of the body in ways never possible before.

These things have a real cult following. Here’s a great resource page:

http://www.gpsrunner.net/

Follow the Garmin link to see a graphic that would have looked science-fictional not long ago. Yes, there are lots of people who are both fitter and geekier than me.