There's been some question about the accuracy of heart rate formulas, specifically the idea that 220 is actually maximum for all of us. For this reason, it's important to use these numbers as a starting point and combine them with other methods to get a more accurate number for you. Here's how:
1. Use your heart rate monitor during a normal workout and note your heart rate during your warm up.
2. Take your intensity to a level that feels comfortable to you and use a mental Perceived Exertion Scale to rate where you are--it should be around a 4-5. Make a note of your heart rate at this intensity.
3. Now increase your intensity (go faster, add resistance or find a hill and hustle up) until you're at a 7-8 on the Perceived Exertion Scale. Make a note of your heart rate.
4. Now, increase your intensity even more by going as hard and fast as hard as you can until you feel you're at a 9. Note your heart rate.
Using these numbers, you can get an idea of how your heart rate correlates to your intensity and you can tweak your THR zone to find a new low end (which will match 4-5 on the Perceived Exertion Scale). This low end becomes homebase for each workout. Using the heart rate from the highest intensity (matching 9 on the Perceived Exertion Scale) you have a new a high end--a heart rate you can achieve only for a brief period of time. This new THR zone will help you work even more efficiently. Creating workouts using your target heart rate