健身是一种时尚，也是一种乐趣，它使你在健全身体的同时，也使你获得一份轻松快乐的健康心情。但是，健身也要有度，“过则损”。心脏监护器倒是一个好帮手。想知道怎么用吗?不妨看看：

Tend your ticker with a heart monitor

Heart-rate monitors help put workouts in perspective.

They are “the ultimate personal trainer,” said David Wright, a certified fitness specialist and Army master fitness trainer. “The main reason for using a heart-rate monitor is for safety.”

A basic heart-rate monitor consists of a transmitter strapped to the chest or over the breastbone. It send signals to a receiver, usually worn on the wrist. The receiver displays the heart rate – the rate at which your heart is sending blood to your muscles and lungs.

A monitor also can reduce the risk of injury.

“What happens most of the time,” Wright said, “is that the novice will go out and practice at a rate that is way too high. When you overexert yourself, you are at risk for injury, and you could be putting your heart at risk.”

The monitor “can also be used as a way to motivate,” Wright said. “You are able to assess and monitor your own training. It is something a beginner can use and an advanced runner can use.”

Most important, once you buy your monitor, you must find the proper heart rate for your workouts. To do this, Wright recommends this formula:

· Determine the maximum heart rate by substracting your age from 220. For example, a 50-year-old would have a maximum heart rate of 170 beats per minute. You do not want your heart rate to exceed the maximum during exercise.

· Determine you resting heart rate. Sit quietly in the morning before consuming stimulants such as caffeine. Count the number of times your heart beats in one minute. A 50-year-old might have a resting heart rate 0f 75 beats per minute.

· Substract the resting rate from the maximum. (170-75=95 beats per minute). The 95 beats per minute is your hear-rate reserve.

· Multiply the heart-rate reserve by the intensity level at which you want to exercise. For example, a beginner might want to exercise at a 60 percent intensity level (95 beats x 60 percent = 57 beats per minute).

· Add the resting heart rate. (75) to the intensity level (57). In this example, 132 is the target heart rate.

· “The 50-year-old man would not want to go above 132 beats per minute when he exercises,” Wright said. “Most importantly, whatever you do, find your zone. If you exercise any higher than the recommended heart rate, you put yourself at risk for injury.”