Your heart rate measures how hard your body is working. During exercise, your heart rate increases to meet the demands of your muscles. How much your heart rate increases depends on the intensity of your exercise and your overall state of health.
A higher heart rate during exercise can lead to greater fitness, metabolic efficiency, and cardiovascular health. But it’s just one piece of the puzzle.
Lower-intensity exercise—like yoga, Pilates, and walking—may not increase your heart rate as high as other workouts, but can still deliver a number of important benefits for your health.
With Oura’s Automatic Activity Detection, Oura captures your average heart rate and heart rate zones after an activity is automatically tracked or manually added. Under the Activity details, you’ll see a heart rate chart and how many minutes you spent in each of six heart rate zones (from 0 to 5).
What Are Heart Rate Zones?
When you exercise, your body’s demand for energy and oxygen increases to support your working muscles. To meet this demand, your heart has to pump more blood to the muscles so they are sufficiently oxygenated. This causes an increase in your heart rate.
Your heart rate can increase substantially depending on the type of exercise you’re doing, with different cardio zones reflecting the intensity and benefits of each workout.
There are many ways to categorize the different heart rate zones, but generally, they are based on how close you are to your maximum heart rate (MHR). Your MHR is the highest number of times your heart can beat per minute during physical activity, and is highly correlated with your age.
Oura categorizes heart rate zones based on a formula that includes your maximum heart rate and your age, among other metrics.
How Can You Calculate Your Maximum Heart Rate (MHR)?
One simple way to calculate your MRH is by using a formula: Subtract your age from 220. For example, for a 50-year-old, it would be 220 minus 50, so 170 beats per minute would be their MHR.
The most accurate way to calculate your MHR is by doing a stress test in an exercise lab. A stress test uses an electrocardiogram (ECG) to monitor your heart rate while you walk on a treadmill or cycle on a stationary bike. A medical professional overseeing this will have you increase the intensity until you reach your maximum output.
If you know your max heart rate, you can edit it in the Oura App. Go to Settings > Activity > Max heart rate to enter your own value and calculate more specific heart rate zones.
RELATED: Heart Rate Recovery: Why It Matters and How to Calculate Yours
What Are Heart Rate Zones on Oura?
In the Oura App, you’ll see six heart rate zones. All six deliver benefits to your overall health.
While vigorous exercise is great, remember that low-intensity activities and everyday movement can improve your energy and mood, help you manage your weight, and benefit your metabolic health. By monitoring cardio zones, you can optimize your workouts for both performance and recovery. Get your baseline with Oura’s activity-tracking smart rings.
In general, zones 0-1 are considered low-intensity, zones 2-3 are considered moderate intensity, and zones 3 and above are considered high intensity.
The ranges assigned to each zone are calculated using an age-based estimate of your max heart rate (max HR).
| Zone | Percentage of Max Heart Rate | Description | |||
| Zone 0 | ≤ 49% of max HR | You’re either fully at rest or moving slowly. This zone is associated with recovery. | |||
| Zone 1 | ≥ 50-59% of max HR | You’re moving at a light, steady pace, promoting circulation without much strain. It’s still easy to speak in full sentences. This zone is associated with metabolic health, and is common in warm-ups, cool-downs, and low-intensity activities. | |||
| Zone 2 | ≥ 60-69% of max HR | You’re moving at a light-to-moderate pace that may cause mild strain but feels sustainable. At this intensity, you’re still able to talk in full sentences, but it feels a bit harder than zone 1. This zone builds endurance and supports metabolic and cardiovascular health. | |||
| Zone 3 | ≥ 70-79% of max HR | You’re expending moderate-to-high amounts of energy and feeling more strain. Your breathing is more labored and it’s becoming difficult to maintain a conversation. Zone 3 benefits your cardiovascular fitness and muscle strength. | |||
| Zone 4 | ≥ 80-89% of max HR | You’re exerting near-max effort—moving with high intensity and really challenging your body. Time spent in this zone has high cardiovascular benefits but should be balanced with recovery. At this intensity your breathing is much quicker and you can only speak a few words at a time. | |||
| Zone 5 | ≥ 90-100% of max HR | You’re working at an all-out effort, and your heart and respiratory system are working at maximum capacity. This zone should leave you breathless while fortifying your cardiovascular and metabolic health. | |||
Where Does the Anaerobic Zone Begin?
Zones 4 and 5 are commonly known as „the anaerobic zone.” More precisely, it begins at your second lactate threshold (LT2), which is the point where lactate starts building up in your blood faster than your body can clear it. That line doesn’t fall at the same percentage of max heart rate for everyone: for some people Zone 4 is squarely anaerobic, for others only Zone 5 is.
RELATED: What Counts as Low, Moderate & High Intensity Exercise?
Which Heart Rate Zone Improves VO₂ Max?
All of them can. VO₂ max is the maximum amount of oxygen your body can take in and use during exercise, and people can have different bottlenecks limiting it. One person might have a relatively over-developed cardiovascular system, but be limited by poor mitochondrial function and density. This person would benefit most from HIIT. Another person might have excellent mitochondrial capacity, thanks to the demands of a sport like ice hockey, but be limited by their cardiovascular system. This person’s VO₂ max would be hugely boosted by Zone 1–3 work.
Oura’s automatic VO2 Max feature, currently in Oura Labs for Oura Ring Gen3 and later, estimates your VO₂ max passively from your regular GPS-enabled walks, runs, and hikes.
Aerobic vs. Anaerobic
Aerobic means „with oxygen.” Anaerobic means „without oxygen.” In exercise physiology, the terms describe how your muscles are producing energy at a given moment. Aerobic activity uses oxygen to fuel steady, sustained effort—walking, easy running, most of a long ride. Anaerobic activity draws on energy stored in the muscle itself to fuel short, intense bursts: quicker to access, but limited in supply, and impossible to sustain for long.
| Aerobic (Zones 1–3) | Anaerobic (Zones 4–5) | |
|---|---|---|
| Oxygen | Oxygen-fueled: supply meets demand | Oxygen-limited: demand outruns supply |
| Primary fuel | Fat and carbohydrate, plus lactate as fuel | Stored ATP and phosphocreatine, then muscle glycogen |
| ATP yield | Very high—30+ ATP per glucose molecule | Very low, 2–3 ATP per glucose unit |
| How long it can last | Minutes to hours | Seconds to roughly a minute |
| Byproducts | Carbon dioxide and water | Lactate and hydrogen ions, plus an oxygen deficit to repay |
| Talk test | Full sentences to short sentences | A few words, then none |
| Recovery cost | Low to moderate; can be done most days | High |
Do You Need a High Heart Rate While Exercising?
Having a high heart rate isn’t a requirement for an effective workout. However, research points to clear advantages to getting your heart rate up during a workout, as different cardio zones activate specific physiological responses that enhance endurance, strength, and overall heart health.
What are the potential advantages of higher-intensity exercise?*
- Improves overall cardiorespiratory fitness: A 2014 study in the British Journal of Sports Medicine found that high-intensity training was twice as effective as moderate-intensity exercise for improving cardiorespiratory fitness specifically as measured by VO2 max.
- Improves insulin sensitivity: A 2017 study showed that HIIT counteracted elevated glucose, insulin, and free fatty acids in male participants, helping maintain insulin sensitivity even in an insulin-resistant state.
- Delivers benefits in a time-efficient manner: As few as four minutes of a Tabata-style HIIT has been shown to improve VO2 max and anaerobic capacity by 28%, outperforming moderate-intensity workouts.
- Lowers LDL cholesterol levels and blood pressure
*”High-intensity exercise” is not the same as anaerobic HR zones
What are the potential drawbacks of higher-intensity exercise?
It’s important to note that while high-intensity exercise benefits nearly everyone, it may exacerbate underlying health conditions for some individuals; hard efforts (Zones 4–5, where a person can only speak a few words at a time) can carry risks when certain health conditions aren’t under control.
People with heart conditions, such as chest pain, a recent heart attack, worsening heart failure, an irregular or racing heartbeat, a heart valve problem, or an enlarged or weakened section of the aorta (the body’s main artery), should talk with a doctor before increasing intensity. The same goes for people with uncontrolled high blood pressure, blood sugar well outside their target range, or a fever or infection. In most cases, the goal isn’t to stop exercising for good. It’s to stabilize the condition and get medical clearance so activity can be built up safely.
Anyone who experiences chest pain, unusual shortness of breath, dizziness, or fainting during hard exercise should stop and seek medical care right away. In some cases, extremes of exercise may predispose healthy individuals to increased risk of other health conditions.
| Member Story: Dave K., an avid CrossFitter, saw an abnormally high spike in his resting heart rate. This prompted a doctor’s visit, who diagnosed him with atrial flutter. He was advised to switch to lighter-intensity exercise until he recovered. |
What are advantages of lower-intensity exercise?
Lower-intensity training, such as walking or stretching, may not be as heart-pounding as a HIIT session, but it delivers several health benefits.
- Activates the parasympathetic nervous system: When this system is activated, your heart rate and blood pressure lowers, and important autonomic functions, like digestion, occur.
- Improves markers of heart health: A meta-analysis published in the European Journal of Epidemiology found that walking for 30 minutes a day, five days per week, decreases the risk of coronary heart disease by 19 percent.
- It’s accessible: Many people of all fitness levels can do low-intensity exercise, such as walking and stretching, and reap the benefits.
- Improves sleep quality: A study in the journal Sleep Health, researchers found that low-impact, low-intensity physical activity improved multiple markers of sleep quality.
- Promotes recovery: Low-intensity exercise can reduce post-workout muscle soreness by keeping your muscles flexible, speeding up the overall recovery process.
READ MORE: How Sleep Helps Muscle Recovery and Growth
The Bottom Line
While you don’t always need to see a high heart rate during exercise to get healthier and fitter, a workout routine that combines high heart rate activities (>80% of MHR) with lower heart rate activities (<70% of MHR) leads to the best health and performance outcomes.
In fact, during lower-intensity exercise, your heart rate may not be substantially elevated but it still has an array of health benefits that make it a vital component of your fitness routine. Lower-intensity exercise improves heart health, is suitable and safe for all, and can help combat stress without needing to put your body under strain.
Frequently Asked Questions
What is a heart rate zone?
A heart rate zone is a range of heartbeats per minute that corresponds to the intensity of your exercise. These HR zones are typically calculated as a percentage of your maximum heart rate (MHR), which is the fastest your heart can beat during physical activity. Different zones provide different health benefits, from improving endurance to boosting cardiovascular fitness.
How do I find my maximum heart rate?
A simple way to estimate your maximum heart rate is to subtract your age from 220. For example, if you are 35, your estimated MHR would be 185 beats per minute. For a more precise measurement, a medical professional can perform a stress test.
What are the benefits of a high heart rate during a workout?
Exercising at a higher intensity, which results in a higher heart rate, can significantly improve cardiorespiratory fitness, insulin sensitivity, and muscle mass. High-intensity workouts are also time-efficient and can boost your VO2 max (maximal oxygen consumption), indicating a stronger cardiovascular system.
Do I need to get my heart rate up to have a good workout?
No, you don’t always need a high heart rate to get an effective workout. Lower-intensity activities like walking, yoga, and stretching still offer important benefits like reducing stress, improving sleep quality, and aiding in muscle recovery. A balanced routine that includes both high- and low-intensity exercise is often the best approach for overall health and performance.
Is 170 bpm anaerobic or aerobic?
It depends on your maximum heart rate. Using the 220−age estimate, 170 bpm is about 85% of max for a 20-year-old (Zone 4, high intensity), about 94% for a 40-year-old (Zone 5, all-out), and at or above the estimated maximum for someone in their fifties. As a rough rule, it’s an anaerobic effort for most adults over 35, but the estimate carries ±10–12 bpm of error.
How long should I do a high-intensity workout for?
A typical HIIT workout alternates work and recovery for a total of about 20 to 60 minutes. The American College of Sports Medicine describes work intervals of 5 seconds to 8 minutes at 80–95% of your estimated max heart rate, with recovery periods about as long at 40–50%. ACSM suggests building an aerobic base first, then starting with one HIIT workout a week and adding a second as you feel ready. If you have a known heart condition, or symptoms like chest pain, dizziness, or unusual shortness of breath, talk with your doctor first.
How is Cardio Effort different from heart-rate zones?
Cardio Effort considers the duration and intensity of an eligible workout, using heart-rate response when available. Heart-rate zones show how much time you spent at different intensity levels during a workout.
This article is for informational purposes only and is not medical advice. Oura is not a medical device and does not diagnose, treat, or prevent any condition. Talk with a healthcare provider before beginning a high-intensity exercise program, particularly if you have a cardiovascular condition or risk factors.