He Says Monitors Have as Many Bells and Whistles as You Need. And Maybe More.

If you want just a heart rate monitor, major manufacturers such as Polar and Timex offer basic models for as little as $50 or $60. These won't go far in terms of data analysis and won't measure speed or distance if you walk, run or bike. But they are fine for tracking a vital statistic. For about $150, Polar's new FT40 gives each user a "dividing line," based on heart rate, between his "fat-burning" and "fitness" zones. This is a somewhat artificial distinction, related to how the body uses energy, but it's one that Polar thinks simplifies things. For about $20 more, the Polar F11 provides a more sophisticated set of heart rate training zones and will automatically construct a weekly program based on them. Both let you upload to an online journal that totals what you do and compares that with set goals.

Do speed and distance matter?

If you are a walker, runner or biker, and want to keep track of how far and fast you go, you'll need a unit that is compatible with some sort of speed and distance sensor: a small device that clips onto your shoelace, separate sensors for your bike or one of the increasingly popular GPS units. Look for package deals where the sensor is included with the watch. Garmin's Forerunner 405 comes with a GPS device built into the watch-size unit, an engineering marvel that includes a nifty iPod-style touch control around the outer bezel. At $300, it is pricey, but it makes for an easy, one-stop purchase. Keep in mind that GPS devices are only as good as their signal. If you run on an indoor track or in a canyoned urban neighborhood, or don't want to risk a loss of data, you might want to buy a foot sensor separately as a backup.

Polar, given its background as a fitness company, has put its focus on improving the foot sensor and delivers a unit that will measure stride length and cadence, important if you are trying to improve your running style and speed. Both Polar and Suunto sell separate GPS receivers for their higher-end watches, but the muffin-size, strap-on units seem almost antiquated compared with the Garmin. Bike units, which use magnets on the wheels and pedals to measure speed and cadence, are sold separately by each company.

One tip: If you use a foot sensor, calibrate it to a known distance. Out of the box, I found them off anywhere from 6 to more than 10 percent. It is an easy adjustment to make, and an important one.

Does GPS matter?

If you're trail-running to Grandma's house and want to make sure you get home -- or want to save favorite routes and have access to directions during a workout -- Garmin is the choice. The Polar and Suunto GPS units will track speed and distance, but the watches don't have the navigation features that Garmin offers -- helpful, as one Suunto executive noted, if you want to know how fast you went on a downhill ski run, but not so much if you are lost in the backcountry.

One downside to the Garmin: It is an energy hog, so be sure your escape from the backcountry does not take too long. The rechargeable battery runs down pretty steadily and needs to be clipped to its charger when you are not using it.