For nearly a century, riders were doing races like the Tour de France based only on perceived exertion. They would go out, and ride to their limits based entirely off of how they felt. And they were very fast doing so.
Then came more technology. Heart rate monitors, power meters, and more, all designed to help you understand your abilities and learn from them. But it's not simple, and what's worse is everyone is different. Learning how to use them then is a process of individual trial and error. So, how do you use a heart rate monitor (HRM)? You start with data.
You need a baseline before you do anything. Since everyone's body is different, what might be a max, or threshold heart rate for you, might be a low heart rate for me. Head out the door with your HRM and do some workouts. Push it to the limit if you can a few times, just to get an idea of where your upper numbers are. The idea is to identify a few key heart rates:
- What your max heart rate is
- What heart rate you can sustain for an hour
These two numbers will help you then develop your heart rate "zones."
Look over the data you've collected from a few workouts and begin working with some common guideline formulas. I like Joe Friels formula, but it's not perfect, it's just a starting point for developing your zones. Ultimately, over time you will learn how your body feels at certain efforts and heart rates, and you can adjust your zones accordingly.
One formula I would never recommend is something based purely on your max heart rate. Without a field tests of what you can do for an hour all out in addition to what your max is, setting up your zones is challenging. Here is Joe's formula:
- Zone 1 Less than 81% of LTHR
- Zone 2 81% to 89% of LTHR
- Zone 3 90% to 93% of LTHR
- Zone 4 94% to 99% of LTHR
- Zone 5 100% to Max
Knowing what ranges you live within while performing will allow you to appropriately gauge your efforts. Again, that 1 hour heart rate is important, and that is your Lactate Threshold Heart Rate (LTHR). Your lactate threshold is when your body is now producing more lactate than it can get rid of quickly. You can ultimately only last about an hour at this level of intensity before your muscles are toast. Knowing where that is, will allow you to optimize training. Most research shows that for the fastest gains in endurance sports, working just below this level will help you develop and get stronger, very quickly. Thus, determining what your heart rate is at that level, will help you target slightly under that heart rate during your workouts.
For example, here are what my numbers look like according to Joe Friel:
- Zone 1: 0-144
- Zone 2: 145-158
- Zone 3: 157-166
- Zone 4: 167-176
- Zone 5: 177-194
Now, over the years I have found that my numbers are slightly different from these zones. So I've tweaked them to give myself a better baseline for using a HRM effectively. Here is what I use to train:
- Zone 1: 124
- Zone 2: 155
- Zone 3: 170
- Zone 4: 179
- Zone 5: 194
Not vastly different, but enough to make a difference while training. I recommend starting there then, sorting out your zones, then moving on to tweaking them down the line.
Going out and training with this data is a whole different animal. How you should train; what zones you should be in for your workouts; how much time per week you should be in each zone; all great questions that completely depend on what your goals are.
This is the point where having a coach to guide you and teach you how to target your specific goals is crucial. As a general rule of thumb, time spent in zones 4 and 5 will make you strong quickly. But that kind of work will fatigue you quickly, and if you don’t balance it with time in zones 2 and 3, you will burnout quickly and will be grumpy in normal life! Trust me on that one.
So a balanced approach is typically safe. It is smart to spend time recovering each week, typically between hard workouts, so those days are your zone 1 only days. Other days might be zone 2 with a bunch of sustained intervals in zone 4 sprinkled in. Then you might do short zone 5 burst intervals one day. There are a million different types of targeted workouts you can do now, all based on those simple heart rate numbers.
While a HRM can give you an excellent indication of how hard you are working, and are generally consistent day to day, your heart rate will change, lag, or just be low based on a variety of external variables. Hydration, fatigue, freshness, diet, temperature; all of these can impact how your heart rate responds on a given day. So keep that in mind if you see inconsistencies from one day to the next.
Much more could be said, and books have been written on the subject, but these are the basics. Use them wisely and carefully, and always ensure your heart is healthy enough for rigorous heart rate based training before attempting to push it to it’s absolute limits!