Target Heart Rate For Fat Burning
There is a lot of confusion about the "fat burning zone" and the "cardio zone" that the charts on the machines refer to. The idea that you burn more fat at a lower heart rate is a half-truth that doesn't tend to be very helpful.
When you do a cardio workout, you're using your fat stores and your food energy for calories. At a lower heart rate, you burn a higher percentage of those calories from fat. However, at a higher heart rate, you burn more total fat calories, as well as plenty of those food calories that just would have been stored as fat, anyway. Basically, it makes sense to stop worrying about what "kind" of calories you're burning, and to just burn as many as possible.
In my opinion, the main reason for the "fat burning zone" on the cardio machines is to encourage you to not give up and to keep working out, even if it's hard for you to get your heart rate up high. And hey, that's not such a bad thing. Something is always better than nothing, so just do your best!
Many people have asked me how to determine their "target heart rate" for cardio. They don't want to waste their cardio workout by not working hard enough, or even by working too hard.
First of all, sometimes it's better to use the "perceived rate of exertion scale." This is especially important for people who are taking blood pressure medications that regulate their heart rate. Basically, imagine a scale of 1-10. 1 is sitting there, bored. 10 is working so hard that you'll have to quit at any moment. You should be around a 5-6 most of the time during your cardio. If you're doing interval training, you should alternate between a 5-6 and an 8-9.
If you aren't on blood pressure medications and your doctor has given you the OK for cardio exercise, you can use the Target Heart Rate formula. Basically, it is a minimum heart rate that you should try to reach as you are doing your cardiovascular exercise. It will help make sure that you're burning a maximum number of calories.
Here is a formula for figuring out your target heart rate:
THR= 220- age - RHR x .75 + RHR
THR stands for target heart rate, and RHR stands for resting heart rate. Start by checking your pulse, which is your heart rate when you've been resting. For best results, test this when you've been sleeping or sitting for a little while. Check how many beats you feel in a minute. (Or, time for 30 seconds and then multiply that number by 2)
Then, follow the formula above. Subtract your age from 220. Then subtract your pulse. Then multiply that number by .75 (or .85 if you are in great shape). Then add your pulse back in.
The reason this method takes your pulse into account is to make your target heart rate more accurate. Instead of just lumping you into a group with everyone else your age, it personalizes the target heart rate to your changing fitness level.
Once you figure out your target heart rate, that should be the minimum goal. If you get above your target heart rate, but feel fine, that's okay. Of course, if you have a heart condition, you need to work with your doctor to set your cardio goals.