How I Trained by Heart Rate

I frequently talk about heart rate in my training recaps, so I wanted to do a post for those who are interested in heart rate training. I'll start with the good news: It's easy! When I first started running, before I ever knew anything about running, I trained by heart rate for my first 5K. By simply looking at my Garmin to check my heart rate during runs, I learned what number meant "You're going too fast and need to slow down or else you won't finish the 5K" and just made sure not to go over that number. Easy!

I have read articles on heart rate training that make it sound very complicated, and I'm sure there's a lot more to it that I don't do. I keep it simple. I'm not an expert, but I've found it to be very helpful in my training. Here's how I did it.

Why train by heart rate?
Your body improves differently based on different types of runs. For example, easy runs improve muscle fiber development, energy utilization, capillary development, cardiovascular strength, and structural fitness (from an earlier post on the Hansons Half Marathon Method book.) Very hard runs increase fast twitch muscle fibers, which increase speed. It may be easy to tell the difference between an easy and hard run based on effort, but there other categories, or zones, of effort, and it's hard to tell the difference between them all, at least for me. With a heart rate monitor, you know exactly how easy or hard you're running. So if your training plan calls for an easy run, you know you're getting the benefits of easy running. Check the Running for Fitness site for a description of the different heart rate zones and the benefits.

You can measure improvements. You'll see how hard your body is working at certain paces and can then track how your effort goes down at the same pace. In my last training cycle, my target race pace became easier and my easy run pace increased, and I was able to verify that through my heart rate data (blog post about that here). 

It can help in races. At a half marathon I did during a training run in March, my strategy was to run an easy pace until mile 10 then speed up and finish strong. This race was one of the few that I felt was very successful, even though it was just a practice run and I didn't get a PR. My heart rate monitor helped me achieve my strategy. We all know how easy it is to start too fast in races. When you wear a heart rate monitor, you can easily see if you're running faster than you should be.

What do you need?
Most running watches have a heart rate monitor option. Most of them are straps you wear on your chest. I have heard that some phones can even measure heart rate by putting your finger on it, but the chest strap seems to be the most widely used. I personally don't mind a chest strap, but if yours bothers you, you might try putting Body Glide or something similar under it.
Diagram showing how a chest strap heart rate monitor works
Calculate your maximum heart rate. There are lots of different ways to figure this out. I have read that the best is to run increasingly fast intervals and then look at your heart rate after the third interval. I haven't done that. I used the formula that Runner's World believes is the most accurate: MHR = 205 - (.5 x your age). I don't stress too much about the accuracy of my max heart rate. I have done several formulas, and they're all in the same general range.

Find your resting heart rate. This is easy. When you first wake up in the morning--before you a move a muscle--find your pulse and activate the stopwatch on your phone. Count the number of beats for one minute. That's your resting heart rate. Do it a few times over a week to make sure it's accurate (or average the results if they're different).

You need to know what type of runs your plan calls for. Some plans will prescribe a very specific heart rate, while others will give general descriptions like "easy run" or "long run." I mapped those types of runs to the heart rate zone chart.

The last step is calculating what your heart rate should be on different types of runs. I used the Running for Fitness calculator for this. This method uses a percentage of heart rate reserve, which is a calculation of max and resting heart rates. Here's an article from RW about heart rate reserve if you want to learn more. But you basically plug in your resting heart rate and max heart rate into the calculator, and it will tell you what your heart rate should be for each zone. If you don't know your resting heart rate, you can just guess (60 is the default number in the tool) or just manually calculate percentage based on max heart rate.

How do you use it on runs?
The hardest part is remembering your target heart rate when you're out running. Do your calculations before you go, and keep in mind the last number in the range. For example, if you're doing an easy run and the highest number in your easy run range is 138, you want to make sure your heart rate doesn't go over that number. If it does, slow down, either by slowing your pace or adding walk breaks if you need to. It's acceptable for your heart rate to rise over the range a bit on hills, but otherwise really try to not go over your max number.

Actually, remembering your heart rate numbers may not be the hardest part. For me, an already slow runner, slowing down my pace was very difficult because it was such a blow to my ego. Before I started heart rate training, I thought my easy pace was an 11:30 mile. But when I started going by heart rate, I had to drop down to 13:00-13:30, and sometimes even 14:00 on hills. When you want to see your paces increase, it's hard to see them slowing down so much. The solution? Set your watch to not show pace. On my easy run days, I have my Garmin set to show only heart rate and distance and only see my pace at the mile splits and at the end. The upside to running a slower pace is that your body physiologically adapts, and you'll see your easy run pace increase. Mine is now 12:00-12:30, a full minute/mile faster than when I started earlier this year.

I think I will always use my heart rate monitor because I find it so useful and plan to use it during my next race.

For more info and another perspective, check out Nichole's blog at Grey Shirt Running. She also trained by heart rate and swears by it. She posted some really good information on heart rate training and the stats that measurably show how it helped her.

I hope this is helpful to some of you!