Pushing your workout to the limit may be necessary to prepare for competition, but this same intensity can make some health conditions – such as hypertension – worse, and can be counterproductive to most fitness goals, according to a fitness expert.

Heart rate monitors, which measure your heart rate, are not necessary for a good workout, but the little gadgets – some with hefty price tags – can be handy if measuring the intensity of the workout is important for specific health or competition goals.

"You can get everything you need from moderate to low intensity exertion except for high performance," said Julie Frey, coordinator of the Adult Fitness Program in Indiana University Bloomington's Department of Kinesiology.

What do most people need? Frey said cardiovascular fitness should be considered the foundation for other fitness goals, such as muscle strength or endurance. A healthy heart and blood vessels help the body's muscles use oxygen. It's at this level that fitness improvements usually occur. During high intensity workouts, however, muscles no longer use oxygen as an energy source, which is why high intensity workouts are not necessary to reach most fitness goals.

For a less precise measurement, measure the heart rate at one's wrist or neck. Frey recommends counting heartbeats for 10 seconds and multiplying by six. A little math using the Karvonen Method can help determine general heart rate targets to gauge intensity.

To view the formula, visit http://newsinfo.iu.edu/news/page/normal/3041.html

Frey offered examples below for how intensity targets differ according to goals. The first example is based on a hypothetical overweight woman:

• Lose weight: Her intensity should be in the low-moderate to moderate range, ultimately working up to 60-minute workouts five to six days a week.

• Train for a 5 kilometer race: She should vary her workout, shooting for the low-moderate to moderate range twice a week, the moderate to high-moderate range once a week and a low intensity workout once a week. She should try to workout for 30-35 minutes during the higher intensity workouts, excluding warm ups and cool downs, and 60 minutes during the low intensity workout.

• Reduce hypertension: Her intensity should be in the low to low-moderate range, ultimately working up to 30- to 45-minute workouts four to six days a week.

This example involves a 20-year-old man who is athletic. He wants to remain fit and healthy:

• For the next 10-15 years, he could workout 20-30 minutes at a moderate-high intensity two to three times a week.

• In 20 years, he could de-emphasize the intensity but increase duration and frequency. He could, for example, shoot for a moderate intensity for 30 to 40 minutes four times a week.

Heart rate monitors can be useful to people who have had a cardiac event or condition and have been prescribed heart rate guidelines by their physicians. The monitors also can help novices match how their bodies feels with how hard their hearts are working. Athletes training for ultra-endurance or high-performance sports can use heart rate monitors to pace their performance and ward off dehydration.

Heart rate monitors include a device that is strapped over the chest and a second device that looks like a wrist watch and displays the readings. They can cost anywhere from $75 for a basic model to hundreds ofdollars for models that include software for charting progress and recording workouts. Some can be worn in water. "A heart rate monitor can be a bell, a whistle to help motivate you," Frey said. "Whatever it takes."

For more information on Indiana University Bloomington's Department of Kinesiology, visit http://www.indiana.edu/~kines/