More Geeking Out: Using Heart Rate Zones

This is the third part of a series on heart rate monitors. Here are Part 1 and Part 2 if you missed them.

A heart rate monitor is a window into your heart. It’s fascinating to put on your HR monitor and wear it through a regular day. You’ll see what various activities do to your heart rate. What’s your HR when you’re just sitting at your desk? How about when you walk up a flight of stairs or carry a 2-yr old? What happens when you open your credit card bill? Spike!

But knowing HR zones is how you can really apply and use a monitor as a fitness tool. Once you have a good fix on both your resting HR and your max HR, you can create HR or effort zones for yourself. This will allow you to be more precise and specific in how you train. Here’s how to do that.

1. Take your resting HR for three days in a row and average it–that will be your RHR for this equation. Let’s just say that number is 60.

2. Get your HRmax either by using the highest number you’ve seen in a sustained hard workout, or by using the equation 208 – (.7 x your age). Let’s say that number is 200.

3. Subtract your RHR from your HRmax to get your HR reserve. So, for the numbers above: 200 – 60 = 140. The HRreserve number is 140.

4. Take a specific target HR zone, let’s say you want to stay between 70-80% of maximum HR. First get the lower number in the range by multiplying HRreserve by 70% (.7) and then adding the resting HR back to that number. For our example numbers, that would be (140 x .7) + 60 = 158.

5. Get the upper number in that range by multiplying HRreserve by 80% (.8) and adding the resting HR back to that number. For our example, that’s (140 x .8) + 60 = 172.

6. Now we know that to be in that 70-80% zone, our hypothetical athlete needs to keep her HR between 158bpm and 172bpm.

You’ll also find that these zones correlate to different paces. A long/slow or marathon pace run might be at 60-70% of max. Tempo runs where you are pushing your lactate threshold would be at 70-80% of your max. Harder track intervals will be at 80-100%.

Other factors can effect your heart rate. Heat is definitely one. If you aren’t used to working out in 80 degree weather, you’ll notice a difference–your heart is working harder. If you are sick or battling an infection, you’ll often find that your HR is higher for any given activity. Likewise, if you are over-training (doing too many intense workouts without adequate rest and recovery), you’ll see HR readings that are higher for any given activity. In fact, you can use a daily RHR reading as a guide for your training and overall health status. If your RHR is usually around 63bpm and one morning you see that it’s 68bpm (or more than 5bpm higher than normal), you might take that as a sign you need to have an easier training day and keep an eye out for any symptoms of an infection. You may need to prioritize rest and immune system care.

Finally, as you get to know your HR at any given effort level or pace, you can see your fitness improve. It used to be that running at a 10:00 pace would result in a HR of 157bpm. Now I can run at 9:00 pace and keep my HR under that.

Your Recovery Heart Rate is another strong determiner of fitness. As you have more experience using your HRM, take note of your HR immediately after exercise, and then check it again two minutes later. The closer your HR is to your resting HR, the better your fitness. So as you improve, you should see that number drop (i.e.; you get back to resting HR faster). If you find you usually reach a certain number of bpm at the 2-minute mark, then one day you don’t recover as quickly, it’s another sign that you may need more recovery time between hard workouts.

That’s fitness right before your eyes!

If you have specific questions about heart rate monitors or training with HR zones, get in touch.