As a Myzone user, you’ve probably heard the term “maximal heart rate.” Sounds pretty self-explanatory, right? But when you begin to think about the term a little more, what does maximal heart rate (MHR) really mean to us as exercisers? Let’s peel back some of the layers of MHR.
Q: What is MHR and how do we measure it?
Your MHR should be viewed as the upper limit of what your cardiovascular system can handle during physical activity.
Myzone uses a formula derived by the HUNT Fitness Study to automatically establish your age predictive MAX HR:
211 - [0.64 x your age]
When you enter your age during the registration process, Myzone automatically calculates your MHR. It’s important for you to have a MHR value in the Myzone system, as Myzone uses it to determine your heart rate zones while working out.
Q: Will my Max heart rate change over time?
Your maximum heart rate will reduce as you get older. It will not change aside from this although your ability to maintain a higher heart rate will increase with training.
Q: How does MHR relate to the Myzone Zones?
The Myzone zones (GRAY, BLUE, GREEN, YELLOW, & RED) are directly tied to your estimated MHR in the Myzone system. Here’s a breakdown:
- GRAY Zone: 50-59% of MHR
- BLUE Zone: 60-69% of MHR
- GREEN Zone: 70-79% of MHR
- YELLOW Zone: 80-89% of MHR
- RED Zone: 90-100% of MHR
Q: What are some factors that affect MHR?
- Age: our MHR tends to decrease as we grow older.
- Altitude: Acute exposure to high altitudes may cause a temporary decrease in our MHR. We will also have a higher heart rate during submaximal exercise at a high altitude. With continued exposure to high altitude, our MHR should increase and our heart rate during submaximal exercise should decrease compared to when we were first exposed to high altitude.
- Mode of exercise: The MHR we can achieve during different exercise modalities does vary to some extent. For example, exercisers tend to achieve a higher MHR when running compared to cycling due to more muscle mass utilized in running. Exercises like swimming and upper-body Kranking may also elicit a lower MHR due to the smaller muscle mass of the upper body. We recommend that you set your MHR value to be appropriate for the modality of exercise you perform most often.
- Medications: Some medications will limit the MHR you can and should achieve during exercise. An example is beta-blockers, which decrease your MHR lower than the age-predicted maximum used by Myzone. Be sure to ask your doctor if any of your medications will impact your MHR.
Q: How do I know if my MHR is wrong in the Myzone system?
Although the estimated MHR equation used by Myzone should be accurate for most people, you may need to adjust your estimated MHR somewhat. You’ll be able to determine this by comparing your rate of perceived exertion (RPE) to your Myzone zone during exercise.
A general rule of thumb is:
If your RPE indicates low-to-moderate intensity exercise but your zone indicates high intensity exercise, you need to raise your MHR. Ex: you feel like you are working at a 6 but you are in the YELLOW zone.
If your RPE indicates high intensity exercise but your zone indicates low-to-moderate intensity exercise, you need to lower your MHR. Ex: you feel like you are working at an 8 but you are in the BLUE zone.
Q: How can I check if my estimated MHR is correct?
You can determine if your estimated MHR is correct by comparing Myzone effort zones to your rate of perceived exertion (RPE) during cardiorespiratory exercise. That last part – “during cardiorespiratory exercise” – is important, because RPE doesn’t always match up with exercise intensity during muscular fitness or resistance training.
Rate of perceived exertion uses a scale of 1-10 (1 = lightest intensity, 10 = maximal intensity). For example, you should feel like you’re at about a 6 on the RPE scale when you’re exercising in the BLUE zone (60-69% of estimated MHR), and you should feel like you’re at about a 9 or 10 on the RPE scale when you’re in the RED zone (90%+ of estimated MHR).
If you’re a new Myzone user, pay attention to your Myzone effort zones and your RPE during your first few cardiorespiratory workouts. Do they align closely? Is there an obvious discrepancy?
Q: How do I adjust my MHR in the Myzone system?
If your fitness facility uses Myzone, your trainer or fitness manager will be able to adjust your MHR on the Partner Page of Myzone.org. If you don’t belong to a fitness facility, or if they don't have Myzone yet, you can contact Myzone support by submitting a case ticket and ask the agent to adjust your MHR: https://myzonesupport.zendesk.com/hc/en-us
Keep in mind, if you hit a heart rate value above your estimated MHR during your workout and maintain it for at least 40 seconds, Myzone will automatically update your estimated MHR to the new number you achieved.
In certain cases, you may need to set a limit on your MHR so that you exercise at an intensity that is safe for you. We encourage you to talk to your doctor about exercise and see if you should not be exercising above a certain heart rate. If this is the case, you can ask an employee at your fitness facility to set a MHR limit for you, or you can contact Myzone support.