A couple of weeks ago I wrote down some of the random thoughts I had while I was out on a long bike ride. One of those was, “The older one gets, the more important a heart rate monitor is.”
I shared that thought with some folks on my weekly group ride. It prompted some questions and conversations about heart rate, heart zone training, and heart rate monitors. This post is about those topics.
I was first convinced to pay attention to heart rate zones during a double-century ride with Fast Freddie Rodriguez. He explained that the vast majority of the training he did as a successful pro racer was based on zone 2 heart rate training. Since then it has been the metric that I use more than any other to guide my training.

What is Heart Rate-based Training?
Training based on heart rate is almost exactly what the name implies. Rather than worrying about speed, power, or cadence (running or pedaling) you focus on keeping your heart rate within a specific range. That range can vary within a workout. For example, a training plan that I follow when preparing for long gravel races calls for 20 minutes of zone 2 heart rate followed by 5 minutes in zone 4 and 5 before returning to zone 2 (repeated three times).
Most of the training programs and tools that I’ve used follow a model of five heart rate zones of 1 through 5. 1 is basically a warm-up zone and 5 is your absolute maximum effort. I’ve seen some programs that use seven zones, but that seems like too much to try to keep track of while exercising.
The Idea Behind Heart Rate-based Training
The big idea behind heart rate-based training is to spend a lot time in zone 2. By doing that you build up a strong base that can be relied upon when you do need to up the pace. Then when you do need to up the pace you can stay there longer because you haven’t burned a ton of energy going from 0 to 5 since you 2 has become relatively easy to reach and hold.
Global Cycling Network and Global Triathlon Network both have excellent videos on these topics. I’ve included those videos below.
How to Track Heart Rate
To get the most accurate heart rate readings, a chest strap monitor is the best option. However, some people find them uncomfortable. I don’t find them uncomfortable, I just find them to be less convenient than wearing a watch that has a heart rate monitor function. I wear a Garmin Fenix series watch that easily pairs to my bike’s Wahoo computer.
The downside to using a watch heart rate monitor is that it’s not as accurate as a chest strap monitor. A watch has to be worn correctly (snuggly) in order to be accurate. And because it’s on your wrist there is a lag in reading accuracy. For example, I know what Zone 5 feels like but I don’t see the Zone 5 reading appear until I’ve already been there for 10-15 seconds. The other influencing factor of watch heart rate monitors is the complexion of your skin. In the summer when my arms are really tan, the monitor is not as accurate as in the winter when I’m as pale as a fish’s belly.
How the Heart Pumps Blood
Should you be interested in teaching a basic lesson about heart rate to your students, TED-Ed has a good primer on the topic. That lesson is embedded below.
Bottom Line
The big takeaway from learning about heart rate-based training is that you don’t have to go hard all the time in order to make big improvements in your fitness. In fact, going hard all the time is probably a detriment to making improvements in your fitness. The winning formula seems to be: Have fun, watch your heart rate, and be consistent.
And with that, I’m going for a walk.