How to find target heart rate.

How hard should you exercise and how do you know?

You'll need a way to measure exercise intensity (heart rate is only one of three measurement methods) and then you'll need to decide how hard to exercise. Let's discuss intensity first.

So, how do you measure exercise intensity? Well, there are three methods to find intensity—lungs, heart and brain.

The first way to find exercise intensity is through the lungs. It works by measuring the amount of air you use when exercising and is the most accurate of all methods. This method requires an oxygen mask and lots of other equipment, so it's not very practical.

The second way to find exercise intensity is through the heart. It works by measuring your heart rate and, while in principle is accurate, in reality, it varies with the collection method. The collection method usually consists of a sensor (the most common consists of metal plates attached to a handle you grip, but there are many possibilities). Another, less practical way to measure your heart rate is to stop and take your pulse. Although it's easier to measure your heart rate than your oxygen intake, it's still not ideal.

The third way to find exercise intensity is through the brain. It works—not by sticking sharp probes in the brain—but by self evaluation. Amazingly, studies show it's about as accurate as the first two methods. No equipment is needed, just come up with a number from one to ten, where one is very low intensity and ten is full intensity.

Now that you understand how to measure intensity, how hard should you exercise?

This depends on a number of factors, like what kind of shape you're in, what medicines (including over-the-counter) you take, and what your goals are. Without knowing your situation, I can't give you an exact target, but I commonly recommend starting with an intensity of "moderate".

So what values match a moderate exertion? Using the "brain" method, simply workout at the 3-5 level. Using the lung or heart methods is trickier. First, you need to determine your maximum level (usually with pre-test), then you need to select one of several formulas (e.g. percent of maximum, or percent of capacity). Age is a parameter in some formulas. I won't go into more details due to the size and complexity of the descriptions. Let the experts worry about these first two methods of measuring intensity.

Summary: You started out asking about target heart rate, and I took you on a quick tour of the different ways to measure exercise exertion levels, ultimately showing that target heart rate may not be the best method.

Recommendation: Measure how hard you're exercising with the "brain" method—merely come up with a number from one to ten that best shows your level of exertion. Consider a moderate (3-5) level at first.

If workouts are boring, or not enjoyable, or they aren't helping you meet your goals (say, weight loss), find someone experienced at exercise to help. Don't settle for second best—if it's not working, or it's not enjoyable, it's not right—make changes today!

Author's Bio: 

Greg Mumm is a fitness trainer who's spent a lifetime collecting knowledge that can help you lose weight and gain energy. He even wrote a book, available at