Guide to Heart Rate Training for Runners9 min read

As the saying goes, “practice makes perfect,” and this can definitely be said of running. The more you run, the better you get at it in terms of how long you can, how fast you can run, etc. Now let’s think about that, why does running more enable you to run longer and faster? It really all comes down to the heart. The heart is a muscle, and as with all muscles, the more you use it, the more efficient it gets. In this article, we’ll explore heart rate training, how it works, what the benefits are and why you should train using a heart rate monitor.

Balancing Act

When it comes to running, there are so many different ways to train. There’s fartlek runs, tempo runs, long runs, recovery runs, VO2 max runs, etc. All of these types of runs all have one common characteristic: they challenge your heart but in different ways. Ultimately, improving your ability to run faster and longer is basically a balance of heart rate training and structural foundation, which is your body’s ability to withstand the constant pounding from running increased mileage. In a perfect world where you never get injured and your heart never gets tired, you could basically just run VO2max runs every day and you would see exponential increases to your fitness within a span of days. The problem is that our bodies can’t handle maximum efforts every day lest we get injured or suffer from overtraining. So it’s all about finding that perfect balance.

Getting Started with Heart Rate Training

So how do you improve your heart’s efficiency? Well, to do that, you can simply follow training plans that will work out your heart or you can get scientific about it and train by heart rate, also known as heart rate training. I’m a huge fan of heart rate training since it allows you to better understand how your body and heart are reacting to your workout.

To get started with heart rate training, you’ll need to buy a heart rate monitor. There are two types of heart rate monitors:

1. Chest Strap – One that you have wrapped around your chest with the sensors near your heart
2. Wrist-Based – Generally just a watch that measures your HR from the top of your wrist

A chest strap heart rate monitor, such as the Garmin Heart Rate Monitor, is significantly more accurate than a wrist-based heart rate monitor, such as the Garmin 235, since it generally has better contact and it’s nearest to the source. With wrist-based heart rate monitors, the technology has definitely gotten better but I’ve found that the heart rate can still be volatile while the chest strap is much more stable. In my opinion, if you’re serious about heart rate training, you should go with the chest strap heart rate monitor.

Heart Rate Zones

Once you have your heart rate monitor, it’s time to determine your heart rate zones so you will know if you’re training at the right intensity levels. There are two methods to determine your heart rate training zones:

1. Maximum Heart Rate (MHR)
2. Heart Rate Reserve (HRR)

Your maximum heart rate is generally calculated by the formula: 220 minus your age. However, from my experience, that really understates your maximum heart rate by 10-20 beats per minute and it’s much better to do an exercise to figure out what your max heart rate is. A few exercises you can do to get a more accurate read of your max heart rate is to sprint up a hill with a steep incline for 400 meters, jog down and repeat this three times. By the time you finish the 3rd 400 meter run up the hill, take a look at your heart rate and that should give you an idea of your maximum heart rate range. Another exercise you can do is to simply run a 5k all out. By the end of the race, your HR reading is likely within your maximum heart rate range. After either one of these exercises, I would add 3-5 beats per minute to determine your “true” max heart rate.

Your heart rate reserve is your maximum heart rate minus your resting heart rate. Your resting heart rate is generally the heart rate you have right after you wake up from a night’s sleep. So let’s say your maximum heart rate is 200 and your resting heart rate is 60, then your heart rate reserve is 140. 

To determine your heart rate range for each zone level using the maximum heart rate method, you would take the zone level percent from the table below and multiply it by your MHR. So for example, using 200 as our MHR, a level 3 bottom end of the range would be 75% x 200 = 150 and the upper end would be 172.

To determine the heart rate zone range once you know your HRR, you multiply the HRR by the table’s HR %. So for level 3, using our example from earlier, you would multiply 140 by 70% to get 98 and then you add back your resting heart rate which is 60, so 98 + 60 = 158. So 158 to 172 would be your heart rate range for zone 3.

The heart rate zones:

Zone Level	Maximum Heart Rate	Heart Rate Reserve
1	60-68%	50-61%
2	69-74%	62-69%
3	75-86%	70-80%
4	87-93%	81-90%
5	94%+	91%+

Running Intensity Levels

Generally when it comes to heart rate zones:

1. Zone 1 is considered intensity levels that are very light, such as walking. 
2. Zone 2 is for easy runs also known as recovery runs 
3. Zone 3 is your sweet spot for aerobic training or moderate runs
4. Zone 4 is your anaerobic threshold or tempo runs
5. Zone 5 is your VO2 max or speed workouts

Most of your runs should be in Zone 2 or 3 in any given week as these are the zones in which you’ll be able to increase your fitness the most without taxing your body too much. Zone 2 runs, while easy, should still provide a light fitness improvement and are usually thrown in there to help you recover from the previous day’s harder workout.

For those training for longer distance runs such as half marathons or marathons, your long runs will generally be deep in Zone 3 and potentially touching Zone 4 towards the end of the run since your heart rate tends to drift higher due to cardiac drift.

More on Cardiac Drift

Cardiac drift is basically where your heart rate drifts higher despite similar intensity levels. This is likely due to increased core body temperature and the body needing to cool the skin. In the image below, you can see my heart rate trend over the course of a ~2 hour run where my average heart rate is drifting upwards gradually despite running around the same pace.

Over the course of a marathon for example where you’re running mostly even paces, your average heart rate per mile will likely increase by 20+ bpm by the end of the race from where you started. If the marathon is warmer than normal, your average heart rate will likely drift up faster.

Benefits of Heart Rate Training

Heart rate training is incredibly beneficial for anyone who is serious about running and wants to be more scientific with their performance and running statistics. By training at specific heart rate zones consistently, you can continue to push to improve your fitness while balancing recovery. On days after a hard workout, it’s best to slow down and run at an easy pace, trusting your heart rate to keep you accountable since it’s a much more accurate measure of effort vs. perceived effort. If you’re not running in the  lower end of the zone 2 range, you’re most likely working too hard on your following run which may make you more prone to injuries if you’re doing too many higher intensity workouts without proper rest or recovery workouts.

One of the major heart rate training benefits that I’ve observed is simply watching your aerobic capacity improve based on the pace you can maintain at certain heart rates. When you first start using a HR monitor, you may notice your average 8:00 minute/mile pace may have you at a 160-165 heart rate. Then after a few months of training, you’ll find that you can now do 8:00 minute miles at a 150-155 heart rate. That observation alone is incredibly motivating since you can see your body becoming more efficient and able to maintain faster paces at a lower heart rate.

Another benefit is that heart rate training always trumps “perceived effort” or “pace” in my opinion. For example, as a marathon runner, I’ve set goals such as 3 hours and 30 minutes for a marathon which translates to an 8:00/mile split throughout the race. In a number of races, I’ve been very consistent in hitting 8:00 miles only to “hit the wall” around mile 20-22. When I started monitoring my HR throughout the marathon, I knew from experience that my HR had to start in the low 160s and would slowly creep up as I ran more miles during the race. If I was running and I noticed my heart rate was hitting the 170s early on, I would slow my pace down. While this is not ideal, sometimes conditions and how you’re feeling that day will just result in not being to maintain a faster pace at a designated heart rate. By keeping my heart rate at the designated targets for “marathon pace,” I was able to ensure that I didn’t overexert myself early on which resulted in negative splits.

Finally, one last benefit to heart rate training is that it just enables you to train at the appropriate heart rates given the training exercise you’re doing. If you’re doing a tempo run, you’ll know if you’re going too fast or too slow based on your HR. It’s important to neither train “too fast” or “too slow”; the former tires you out too much which increases recovery time, and the latter slows your progress toward your race day goals.

In Closing

There are many ways to train when it comes to running. Using a heart rate monitor is just one of the ways to train. I personally believe it is the most scientific and precise way to train but to each their own. Hopefully if anything, this article has provided you at least with some insight into the benefits of HR training.