Knowing your target heart rate will help you ensure that you don't overdo it during your workout. Here is a simple way to calculate your target heart rate.
Take your heart rate in a resting position. To find your resting heart rate, choose a time when you haven't recently been moving around or exercising. First thing when you wake up is a great time, but even after watching TV for a bit will work. Find your pulse and count the number of beats in 15 seconds. Then multiply it by 4 to get the total number of times your heart beats in a minute. That's your resting heart rate (HR).
Figure out your Standard Maximal Heart Rate. Now you need to figure out your maximum heart rate. Start with the number 220, and subtract your age from it. Then take the resting heart rate that you calculated earlier and subtract it from this number. This number is referred to as your Standard Maximal Heart Rate.
Determine the low end of your target heart rate. Take the answer you got in step #2 (standard maximal heart rate), multiply it by .060, and then add your resting heart rate to it. This is the low end of your target heart rate.
Determine the upper end of your target heart rate. To find your maximum target heart rate, use the answer you got in step #2 (standard maximal heart rate) and multiply it by 0.70. Then add your resting heart rate to the result. The number you end up with is the upper end of your target heart rate.
Know what to do with the information. Now that you have calculated the lower and upper end of your target heart rate, you just need to know what to do with the numbers. You have calculated your target heart rate zone, which is where you need to aim to have your heart rate while you're working out. If it falls below your target heart rate zone, you're not working hard enough and you won't meet your weight loss and fitness goals. On the other hand, if you target heart rate is above this optimal zone that you just calculated, you're overworking yourself and you're putting your health at risk. Try to keep your heart rate within the target heart rate zone that you just calculated so that you'll maximize your workout efforts without risking your heart health.
Consider a few other tips. Working out properly includes knowing your target heart rate. But you should also be aware of a few other fitness tips. If your heart rate is in the target zone, then you should be able to tell just by how you're breathing. You should be breathing a bit heavier, but still be able to carry on a conversation comfortably. And if you have relatively good fitness levels, aim to work out at 80% of your maximal heart rate 3 times a week, for at least 20 minutes. Working at just below your upper heart rate maximum will do you the most good when it comes to meeting your health goals.