A Brief Overview of The Heart and Heart Rate
The heart is a muscle that contracts like a pump over 100,000 times per day to deliver oxygen, fuel, and essential nutrients to every cell in the body. Circulation, made possible by the heart, also carries away waste products of metabolism, such as carbon dioxide.
Your heart rate is the measure of how many times your heart beats in a minute. Heart rate measurements are used to understand overall heart & vascular health, as indicators of physical fitness, and as a guide to monitor exercise intensity.
Advantages of Using a Heart Rate Monitor
Heart rate is one of the best measures of how hard your body is working, especially during fast-paced movements such as cardio workouts. Knowing your heart rate in real-time helps you to know when to increase or decrease your intensity depending on your goals or the type of exercise you’re doing.
Training For Specific Goals
Each heart rate zone comes with its own unique benefits. Very low-intensity training for long periods can burn fat and improve mitochondria (cellular energy). Moderate-intensity exercise, such as aerobic, is known for its cardiovascular benefits. More strenuous exercise zones can give the same cardiovascular benefits as aerobic exercise in less time. Additionally, more strenuous exercises provide greater fat-burning value for hours after working out, known as a post-workout burn. A heart rate monitor can ensure you get within specific zones to reap the benefits of the higher zones. However, it can also serve as a restraint from pushing too hard when the desired goal is recovery or mitochondria enhancement, such as Zone 2 training.
Training With Intensity
Tracking your heart rate in real-time during exercise can significantly impact motivation. There’s something about having target numbers and knowing when you need to push just a little harder to get into the range to reach maximum benefits. Chasing a particular heart rate can be a driving force to get an extra 10-20% effort. The added effort makes for a more strenuous session and helps many people get more out of their workouts.
While some people use heart rate monitors to push themselves, others can use them to know when to back off. Exercising too close to your max causes fatigue, which leads to a breakdown of form and technique. Lifting heavy weights or performing technical moves while exhausted is dangerous, increasing your risk of injury. Understanding heart rate zones and knowing your real-time heart rate can allow you to train safely, especially if you have a history of injuring yourself or a heart condition that needs to stay below a particular threshold.
Over time, you can use the data from your heart rate monitor to track your fitness progress. Improved heart rate recovery times, ability to work out comfortably at higher intensities, or spending more time in a specific zone can all indicate improved fitness levels.
Understanding Heart Rate Zones
Heart rate zones are based on percentages of your maximum heart rate. 100% would be your absolute highest heart rate when you’re exerting 100% maximal effort with nothing left to give.
Finding Your Max Heart Rate
You can estimate your maximum heart rate based on age. For example, subtracting your age from 220 will give you a rough estimate. However, it’s recommended to get more precise with testing. For example, you can monitor your heart rate during strenuous workouts to get your personal maximal heart rate. This will require you to push yourself, for example, during a HIIT (high-intensity interval training) session. You’ll usually be able to dial in your personal maximal heart rate within three sessions. Keep in mind that if you’re new to fitness, this number may change as you develop more tolerance to exercise.
Resting Heart Rate & Daily Activities
Before discussing each heart rate zone, it’s helpful to know that your resting heart rate is between 30-40% when completely calm and relaxed. This is when your body is performing basic biological functions for survival. It is best to assess first thing in the morning, and it fluctuates with the time of day, stress levels, training, hydration, etc.
The normal range at rest is 60-100 bpm. A lower resting heart rate is a great indicator of aerobic conditioning and cardiovascular health. For example, 30-40 bpm is the range of an elite endurance athlete. 50 bpm is considered good aerobic fitness, and 60 bpm or less is acceptable fitness. It’s recommended that a resting heart rate of greater than 80 bpm should talk to your doctor.
Your heart rate will get between 40-50% with basic daily activities such as conversing or walking to the bathroom.
Zone 1 (Low-intensity zone)
50-60% of your max heart rate
This is the lowest-intensity zone for exercise and is usually sustainable for long periods. Zone 1 activities are often used to promote recovery the day after intense workouts. Examples are restorative yoga, stretching, or a leisurely walk. Exercising in this zone promotes circulation, removes waste products from muscles, and helps maintain overall cardiovascular health. Moving through full ranges of motion while in zone 1 can be relaxing and meditative, helping to relieve stress and improve mental health. This level of intensity is suitable for all fitness levels, including beginners or those returning from injury, making it a safe starting point for most people.
Zone 2 (Health improvement zone)
60-70% of your max heart rate.
Zone 2 training is between light and moderate, depending on your fitness level. For most people, a full conversation could be held with little difficulty. Examples include a brisk walk, light jog, hiking, or cycling at a sustainable pace.
The primary goal of training in Zone 2 is to improve aerobic fitness by enhancing the body’s ability to use fat as a fuel source and improve cardiovascular system efficiency.
Exercising in Zone 2 is also unique in that it’s the sweet spot for increasing mitochondrial density and function. Mitochondria are the energy-producing powerhouses of cells. Dysfunction in mitochondria is linked to various diseases, metabolic disorders, and dementia, which is why this is sometimes called the health improvement zone. Some experts suggest a more precise range for zone 2 is 65-75%.
The recommended duration of Zone 2 training can vary widely, but it’s generally characterized by longer, sustainable sessions that help to build aerobic endurance. Spending 60-90 minutes in this zone twice a week is recommended to take full advantage of the health improvement benefits. However, it’s essential to tailor the length of your workouts to your individual fitness level, goals, and how your body responds to training.
Zone 3 (Aerobic zone)
70-80% of your max heart rate.
Zone 3 is often called the fitness zone because this is where intensity starts to pick up, causing you to breathe more heavily. Exercising in this zone improves cardiovascular fitness, endurance, and the body’s ability to efficiently utilize oxygen. It helps enhance your aerobic capacity and stamina, making it useful for endurance athletes, such as distance runners, cyclists, and triathletes.
The demand for energy increases in this zone, and your body relies on aerobic metabolism at an elevated rate. The aerobic energy system uses oxygen + glucose from fat to generate energy. Maximal benefits are usually obtained after exercising in the zone for 40-60 minutes.
Zone 4 (Anaerobic threshold)
80-90% of your max heart rate.
Zone 4 training is high-intensity exercise characterized by hard but not maximal effort. Training here improves stamina, performance, and the efficiency of your cardiovascular system. Zone 4 is typically utilized in interval form, mixing short bursts of high-intensity effort with periods of lower intensity to recover, commonly used in various sports and advanced fitness regimens.
Training in this zone has been popularized by Orange Theory due to its “post-burn” effects. This is when your body continues to burn calories for several hours after exercising. A second benefit of training in this zone is that you can get cardiovascular benefits similar to Zones 2 or 3 in a shorter period.
The intensity of Zone 4 requires your body to use the anaerobic system for energy production. With less oxygen, your body needs glycogen (complex carbohydrates) from the liver and muscles. This means that your body burns a much lower percentage of fat compared to the other zones.
The amount of time a person can use this system varies and depends on their overall health and conditioning and the intensity of their efforts. On average, this zone is only sustainable for 2-10 minutes. As with any high-intensity training, it’s important to be conditioned and to consult with a healthcare or fitness professional to ensure it’s appropriate for your health and fitness levels.
Zone 5 (Max effort)
90-100% of your max heart rate.
Zone 5 targets your maximal oxygen uptake, increases aerobic capacity, and improves endurance performance. Training in this zone involves short, intense bursts of effort that are unsustainable for longer than seconds or minutes for most people. Athletes train in this zone sparingly to improve speed, power, and performance. Zone 5 is unnecessary for most people simply interested in health and wellness.
The Best Heart Rate Zone for Burning Fat
Your body burns fuel from fat and carbohydrates in each zone. However, you’ll burn the highest percentage of fat in the lower zones, such as Zones 1 and 2. For example, in Zones 1 and 2, the calories burned from fat will usually fall between 60-80%. In Zones 3 and 4, the body relies on more glycogen, and the percentage of fat burned falls between 20-50%.
It’s important to note that these percentages can vary based on individual fitness levels and metabolism. Also, while lower-intensity exercises might burn a higher percentage of fat, higher-intensity exercises burn more calories overall, which can contribute to more fat loss in the long term.
The Value of Heart Rate Recovery
Heart rate recovery (HRR) is a measure of how quickly the heart rate lowers after exercise, reflecting cardiovascular fitness and the health of the autonomic nervous system. The faster the heart rate returns to resting level, particularly within the first minute after ceasing activity, the more efficient and healthy the cardiovascular system is considered to be.
Ideally, your heart rate will drop by at least 30 bpm in the first minute after strenuous exercise. Endurance athletes will drop 50-60 bpm.
Improving heart rate recovery can generally be achieved through regular cardiovascular training, although factors like age and medication also play a role in its variability.
Which Heart Rate Monitor Should I Use?
Is It Always Necessary To Use A Heart Rate Monitor?
Although heart rate monitors are extremely valuable in enhancing cardiovascular fitness, there are some circumstances in which a heart rate monitor may be an unnecessary distraction. For example, certain movements and exercises are more valuable when done with mindfulness. Focusing on your heart rate during mobility, yoga, or accessory movements could be distracting.
Strength training is another example in which monitoring your heart rate may be less necessary. Your heart rate is not as reliable of an indicator of your max effort for certain exercises, such as a bench press. That being said, it can be a useful tool to watch and discover what your personal heart rate gets to with each individual lift.
Finally, some people are greatly in tune with their bodies or find that monitoring their heart rate is unnecessary or time-consuming for them. Keep in mind that exercise of any kind and in any zone is valuable. The ultimate goal is to move. If monitoring your heart rate is helpful or motivating, get at it. If not, you do you.