hen Leslie Stallings decided to run three marathons in three days, the 47-year-old mother of two didn't pay attention to her times.
"Most runners look at the split for each mile," said Stallings, wellness director for the North Pinellas branch of the YMCA of the Suncoast in Palm Harbor. "But I didn't even think about how fast I was running. I just kept looking at my heart rate monitor."
The device, which allows an athlete to measure her heart rate in real time, has become the training tool of choice for beginners and veterans alike. Today's heart rate monitors are light and relatively inexpensive. A Timex Race Trainer, with its chest-strap transmitter and wrist receiver, sells for $109.95.
"I recommend that anybody who is just starting out on a cardiovascular exercise program get a heart rate monitor," said Stallings. "It gives you an objective, instead of subjective, view of your training."
First, a word of caution: Dr. Kevin Garner of the Cardiovascular Center at Suncoast Medical Clinic says it's a good idea to consult your physician before starting your new training regimen. "The heart rate calculations are just a rough guide. You have to allow for individual variability, which can be affected by medications, age and other factors.''
In general, your heart rate, or how many times the muscle beats per minute, will vary during rest and exercise.
Your resting heart rate is just like it sounds — how many beats per minute (BPM) when you are at rest.
Your maximum heart rate (MHR), in comparison, is how fast your heart would beat if you were being chased around a quarter-mile track by a Doberman pinscher.
You can figure out your MHR two ways:
For a nonathlete or somebody just embarking on an exercise program, start with the number 220 and subtract your age. For example, for this writer, it would be 220 minus 49, or a MHR of 171.
To get maximum benefit from an exercise program, keep your effort at 65 to 85 percent of your MHR. In my case that would be a range, or target heart rate, of 111 (just dogging it) to 145 (here comes that dog).
If you stick to your exercise program, eventually your heart will grow stronger and beat fewer times a minute during the same exercise intensity. "You can see positive gains quickly," explained Charlie Mack, a clinical exercise physiologist at Bayfront Medical Center in St. Petersburg. "Then you will have to adjust. Your numbers will change in order to get the same benefit."
For example, if you hit the treadmill every day, with your heart pumping 130 BPM, after a few weeks you may need to increase speed or incline to achieve that same 130 BPM and feel like you got a workout.
Stallings, the marathoner from Palm Harbor, uses a different formula for fit people to determine maximum heart rate. Start with 205, subtract your age divided by two, and you get the MHR for a reasonably fit person.
The MHR for this 49-year-old fitness/outdoors editor who swims, runs or paddles several days a week would be 205 minus 24.5 (that's my age, 49, divided by two), which equals 180.5. So my new target heart rate would be 117 (easy effort) to 153 (harder effort).
Stallings, who started running in 1996, increased her training last year for September's Tahoe Triple, three marathons in three days around the lake that separates Nevada from California.
Because of the altitude, the races are particularly tough for flatlanders such as Stallings, who trains at sea level.
"I tried to keep my heart rate at 150 beats per minute," she said. "I didn't worry about how fast I was going. I figured my pace would be a lot slower because of the altitude."
At the end of the first day, Stallings found herself in the lead, crossing the finish in 3 hours, 53 minutes, 59 seconds. On the second day, she delivered an even better performance, winning in 3:47:33. A second-place finish on the third day (3:54:18) gave her the best combined time for the three races and a first-place trophy.
"The heart rate monitor took all the guesswork out of it," she said. "I think it made all the difference."
Terry Tomalin can be reached at firstname.lastname@example.org or (727) 893-8808.