Once dismissed as expensive toys for all but serious athletes, heart-rate monitors are gaining respect as an efficient way for time-pressed fitness buffs to get the most out of their workouts. Monitors tell you at a glance whether your heartbeat is in the target range--60% to 80% of your maximum capacity--to reap overall cardiac benefit, while minimizing time wasted by exercising at rates providing little or no benefit.
STRESS ALERT. A monitor's main advantage may well be to warn weekend athletes when their heart rates exceed the proper fitness range, which for the out of shape can be surprisingly low--merely a slow jog. Indeed, great numbers of fitness wannabes overexert themselves in the mistaken belief that they will achieve fitness that much sooner. In truth, they gain little while risking injury and burnout before flopping back on the couch in frustration.
Monitors are easy to operate. The best have a band strapped across the chest that electronically signals a wristwatch that displays your pulse, along with such options as high and low target settings, workout time within the target range, time spent above and below, lap times, average heart rate per lap, and length of workout.
First, determine your maximum heart rate by subtracting your age from 220, for a rough measure, or by a stress test. Then, program target settings representing your optimum workout range. For a 40-year-old man in peak condition, the top setting might be 144 beats per minute for 80% max--the top range of aerobic conditioning--with a low setting of 108, for 60%
As the workout progresses, a beeper signals when you're above or below the target settings. What matters is not how many miles you run or swim but the heart's performance over time--ideally 20 minutes in aerobic range three times a week.
A good monitor doesn't have to cost a fortune. For $189, Polar Edge gives you pulse, high and low alarms, and time above the low setting. Vetta's wireless heart monitor and bike computer ($100) offers similar basics.
BY MAIL. You can find heart monitors at sporting goods stores and in bicycle-
equipment catalogs, such as Performance (800 727-2453). Another mail-order outfit, Creative Health Products (800 742-4478), offers a useful pamphlet about them.
What about the old finger at the throat? It's not very accurate; your pulse falls too quickly once you stop to get a precise reading. Besides, you don't get to pore through a manual and fiddle with programming when you should be on the track.