Why do a majority of endurance sport coaches want/require you to train with a Heart Rate (HR) monitor?

It’s a great question! I know a lot of athletes who have fancy Garmin watches who don’t wear their straps. Personally, I think they are making a big mistake here. Now, HR isn’t a 100% accurate and there is certainly some day-to-day variability (i.e., heat, stress, time of day, etc.); but, overall, HR training is effectivearv

Why should you wear that annoying little strap that is probably chafing your skin? Here are some good reasons:

• Wearing a HR strap ensures that your easy days are easy and your hard days are hard. Most athletes (myself included) have a tendency to work too hard on easy days and not hard enough on hard days. By knowing your HR zones you can ensure that you are working at the correct intensity levels to ensure the best physiological adaptations in your body.
• Wearing a HR strap will aid you in determining what level of intensity you should be working at during exercise. We’ll discuss HR zones later below, but each HR zone specializes and trains different physiological adaptations and metabolic pathways in the body. For example, if you want to improve aerobic or endurance fitness then you should train primarily in Zone 2 (at or below aerobic threshold).
• Wearing a HR strap can help you lose weight and “teach” your body to utilize fat for fuel. Now, we should emphasize the word “can.” Everyone’s metabolism is slightly different and not everyone will have the same results. While working at a lower intensity, HR between 55-65% of maximal HR, the body will utilize more fat molecules to fuel the body instead of glycogen. This is important for long-course triathletes. Staying in lower intensities will allow the body to use more fat vs glycogen (carbs) since fat is essentially an infinite fuel source vs. glycogen, which is a finite fuel source. Note: If you are not an endurance athlete and looking to lose weight, then you want to utilize a different method. We’ll discuss that another time.

As I mentioned above, there are HR zones. Depending who you ask, there may be slightly different versions of the HR Zones. Below is what I use with my athletes:

• Zone 1 – Active Recovery (aerobic) or 50-60% of Maximum Heart Rate (MHR)
• Zone 2 – Aerobic Endurance or 60-70% of MHR
• Zone 3 – Aerobic Stamina/Tempo Pace or 70-80% of MHR
• Zone 4 – Economy (anaerobic) or 80-90% of MHR
• Zone 5 – Speed (anaerobic) or 90-100% of MHR

You might also see zones broken down by lactate threshold. Lactate threshold is the point in training intensity where lactic acid (or commonly called lactate) starts to accumulate in the bloodstream. In a nutshell, lactic acid is a by-product of metabolism at certain exercise intensities.

In order to determine an athlete’s HR zones, an athlete must undergo a Maximal Heart Rate Test. These, of course, can be done in the laboratory setting, but most athletes don’t have the time or money to do so. A field test works for most people.

You’ve probably read in a billion books and magazines that you can calculate your HR using a simple mathematical formula. You can, but, it’s not the most accurate, because the results can vary due to genetic differences between individuals and also between different activities. However, if you’re interested you can calculate your MHR using Karvonen’s Formula:

MHR = 220 – age or

The newer gender specific calculation:

Male = 214 – (0.8xage)

Female = 209 – (0.9xage)

For a more accurate test, I suggest conducting a Maximal Heart Rate Test for each running and cycling. Generally, your MHR will be about 5 beats per minute (bpm) higher during running than cycling.

Disclaimer: Heart rate tests are very stressful on the body. PLEASE get cleared by your medical provider before attempting any HR testing. This is especially important if you have any known heart conditions. Attempt at your own risk.

Here is the below protocol I generally use with my athletes for both cycling and running.

• 5 minutes – warm up slowly to a pace where at the end you breathe a little hard, but are able to complete a full sentence without grasping for air
• 5 minutes – maintain pace, but increase a bit during the less 60-90 seconds
• 5 minutes – increase pace to labored breathing
• 5 minutes – on a gradual incline, increase your pace from breathing hard to breathing very hard
• 2 minutes – all out sprint on incline to maximum pace you can hold for 2 minutes
• 1 minute – push absolute maximum speed (this should feel like hell)
• 10-15 minutes – cool down at an easy pace to bring HR down and breathing should return to normal

This could be done on a flat surface or a treadmill, but I find that a gradual hill works best because my own personal HR increases higher when running on a hill.

The same protocol above can also be utilized on the bike. I recommend using an indoor trainer, but certainly it can be completed outside as well. It is important to maintain a consistent cadence, usually between 85-95rpm (aiming for 90rpm), throughout the test. As you progress through the test protocol, increase your gearing to a harder gear.

Once you have completed your test, download your data. If you have a coach, give the data file to your coach for analysis. If you use TrainingPeaks then you can easily figure out your HR zones through their software. If not, you can do it the manual way. Take your MHR value and multiple it by each zones’ percentage. For example:

MHR = 190

Your zones may vary slightly depending on what HR zone calculations are used. Some zone calculations will break Zone 5 into Zone 5a, 5b, and 5c. If you work with a coach, your coach will help you with this. The above is just one method you can use. Once you know your HR zones, you can begin training. Now, if you have a power meter on your bike, then you will probably train using power metrics and thus you must complete a Functional Threshold Power (FTP) test. More on that later this week!

~ Happy Training!