3.5 billion. That’s the average number of times your heart will beat in its lifetime. We calculate heartbeat in terms of contraction of your heart per minute, which’s called heart rate. According to the American Heart Association, a normal human heart rate at rest is anywhere between 60-100 beats per minute (bpm). But it may also go above or below that range because of the body’s needs to maintain its equilibrium for sustaining daily life functions. For instance, heart rate varies according to a person’s age, sex, physical fitness, sleep, anxiety, and stress etc.
When it comes to getting on the treadmill or hitting the trail, your heart begins to beat fast. The harder you push, the faster your heart beats. And if you’re wearing a fitness tracker, you can see your heart rate during that fitness activity. But should you take into account your heart rate while embarking on your next fitness journey?
“Heart-rate training is a way to combine subjective and objective measures of training,” says Debra Atkinson, a certified strength and conditioning coach in Boulder, Colorado.
Unlike setting a pace or covering a specific distance to achieve a particular fitness goal, heart rate training can guide your workout, track its corresponding effort level required, and help you execute on it effectively for maximum benefit.
You don’t have to just go all in and train harder. Becca Capell, a NASM-certified personal trainer, and senior product manager at iFit, says that heart rate training “helps make your easy workouts easier, your hard workouts harder, and ensures that you’re actually working out at the correct intensity for your goal.”
Now that you know you’re on to something objective and trackable, how do you actually find your training heart rate and the effort level associated with it?
What’s Training Heart Rate
Before going all in on the hardcore data and numbers, let’s understand training heart rate.
Also called as target heart rate (THR), training heart rate is the heart rate level during an exercise or fitness activity, which yields the maximum benefits from a workout. It’s a “sweet spot” between overburdening and not exercising hard enough, says Seth Martin, M.D., M.P.H., and Johns Hopkins cardiologist.
“Target heart rate tells you about how hard your heart should be beating when you exercise. So the higher your heart beats during an exercise or a physical activity, the better fit you’ll be,” says Michael Blaha, M.D., M.P.H.
How to Calculate Your Training Heart Rate?
There are different ways to calculate the training heart rate or target heart rate. But before that, you’ve to find out a variable called maximum heart rate, which depends on a person’s age, sex, and fitness level, etc.
Find your Maximum Heart Rate
The maximum heart rate can be calculated using Fox formula. It’s an age-based formula to find your maximum heart rate (MHR) by subtracting a constant number (220) from your age (in years).
Maximum Heart Rate (MHR) = 220 – Age (in years)
For example, the maximum heart rate of a 25-year-old man is:
220 – 25 (Age) = 195bpm (beats per minute)
It means the maximum heart rate of a 25 years old man is 195bpm.
But here’s the catch: It may not be as accurate and simple as it sounds.
Here’s why: MHR or maximum heart rate may vary when it comes to two different intensive workouts. For example, if you’re running, your body may push beyond that apparent maximum heart rate that you had just calculated. However, in other cases, your heart rate may stay well below that maximum heart rate. It’s because, despite age, MHR also depends on your body size, fitness level, previous medical history, and altitude, etc.
“The heart rate tolerance is specific to each individual and is best determined by experience,” says William O. Roberts, M.D., M.S., a professor in the Department of Family Medicine and Community Health at the University of Minnesota.
That being said, MHR may slightly vary if you factor in other things along with age.
A better way is to use the above formula to calculate your maximum heart rate and also monitor your heart rate during an exercise. If your estimated maximum heart rate is anywhere near the level at which you workout, you should be fine.
If you still want to find a more accurate maximum heart rate, consider taking a cardiac exercise stress test in the lab.
Resting Heart Rate
Resting heart rate can be effective in finding out your training heart rate when using the Karvonen method. For an average healthy adult, the resting heart rate is between 60 and 100 beats per minute.
THR is usually calculated as a percentage range of maximum heart rate, which is expressed as intensity. We’ll list all the percentage ranges for you to work with according to your specific needs.
Now that you know all the requirements for calculating your training heart rate (THR), let’s dive deep into the different methods for calculating THR – one by one.
According to this method, THR can be calculated as a range of 65–85% intensity.
Let’s take an example of a 25-year old adult.
HRmax = 220 – age
HRmax = 220 – 25 =195bpm
For 65% Intensity: HRmax × 0.65 = 195bpm x 0.65 = 126.75 THR
For 85% Intensity: HRmax × 0.85 = 195bpm x 0.85 = 165.75 THR
Based on this formula a 25-year old have THR between 126.75 and 165.75.
But this formula doesn’t estimate your THR accurately. Because:
- It takes only age into account while ignoring other factors such as gender, fitness, medical history, etc.
- The formula doesn’t have any published research backing it.
- A recent study shows that it underestimates THR for people aged above 40 while overestimating it in younger adults.
This method of estimating THR is based on factoring in another variable called resting heart rate (RHR). They use an intensity range of 50-85%.
THR = ((HRmax − HRrest) × % intensity) + HRrest
THR = (195 – 70) x 0.50 + 70 = 132.5 THR
THR = (195 – 70) x 0.85 + 70 = 176.25 THR
(HRmax – HRrest) = HRreserve
Based on this formula, a 25-year should have THR between 132.5 and 176.25.
For someone with an HRmax of 180 and an HRrest of 70 (and therefore an HRreserve of 110):
50% Intensity: ((180 − 70) × 0.50) + 70 = 125 bpm
85% Intensity: ((180 − 70) × 0.85) + 70 = 163 bpm
Training Heart Rate Zone
It’s another method which is the most common one and makes more sense if you’re training, exercising, jogging, or running. It has five different zones based on your maximum heart rate:
- Zone 1: 50 to 60 percent of maximum heart rate (THR = 98-117bpm)
Activities in this zone consist of easy exercises and recovery from an injury.
- Zone 2: 60 to 70 percent of maximum heart rate (THR = 117-137bpm)
Activities in this zone consist of basic endurance training and fat loss exercises.
- Zone 3: 70 to 80 percent of maximum heart rate (THR = 137-156bpm)
Activities in this zone consist of aerobic exercises such as swimming, hiking, kickboxing, and running, etc.
- Zone 4: 80 to 90 percent of maximum heart rate (THR = 156-176bpm)
Activities in this zone consist of anaerobic exercises like heavy weight lifting, strength training, and high intensity movements.
- Zone 5: 90 to 100 percent of maximum heart rate (THR = 176-195bpm)
Activities in this zone consist of maximum efforts that help develop speed and power.
These five zones give people a more realistic approach based on their specific training needs and requirements. Each zone requires a different level of physical exertion and will help you train for recovery, weight loss, muscle gain, and toughness.
Which Heart Rate Zone Should you Train in?
With those five heart rate training zones, you have the choice to pick one and start your workout. However, it depends on your fitness goals. If you look at all the zones, you’ll see that anything below zone 4 is low intensity, aerobic, and easy. However, as we move up, zone 4 and 5, the workout becomes intense, anaerobic, and challenging. With that being said, you should vary the length and intensity of your workouts for maximum benefit. You may start with tempo training (for muscle and strength building), and then move toward a low intensity, aerobic exercise. The point is to alternate intense workout with relatively easy ones to allow for recovery, adaptation, and gaining strength.
To customize your training based on the heart rate zone, keep the following targets in mind:
Gain Strength and Tone up Muscles Mass:
Experts recommend doing at least three to four sessions of resistance training per week. These workout sessions should be on alternate days to avoid overburdening your muscles and allow for recovery. In resistance training, you’re inducing muscular contraction by using resistance. It helps in endurance and muscular strength. Strength training exercises are challenging and of high intensity. For example, set ups, squats, and push ups, etc.
Fitness and Aerobic Endurance:
Aerobic exercises improve endurance, flexibility, and speed. These workouts use oxygen to generate energy for the body. That’s why it’s important to monitor your target heart rate zone, so you don’t end up overburdening your muscles by moving into the anaerobic zone. Cardiovascular exercises or aerobic exercises are best for such fitness goals. Examples are swimming, hiking, jumping, kickboxing, and bicycling, etc.
Trim fats and Get fit:
Do you want to shed some extra pounds and remain fit? Good. You need to couple cardio with resistance training. We consume extra bad calories each day that makes us obese over time. To lose weight, you need to focus on exercises that burn those calories. Begin with intense cardio exercises like running, hiking, and cycling, etc. Most of the fat loss exercises fall in zone 2, where you’ve to maintain a 60-70% intensity of the maximum heart rate. Also, support it with squats and push-ups for the best results.
Dr. Aaron Baggish, M.D., cardiologist, and assistant professor of Medicine at Harvard Medical School outlines a simple workout plan after you determine your training heart rate zone.
- a five-minute warm-up to gradually raise your heart rate to at least 60% of your maximum
- 30 minutes of exercising within your target zone
- a five-minute cool-down to lower your heart rate to normal.
He recommends starting at the low end (60%) of your target zone and then slowly move up to 75%, but make sure you’re not overworking. Plus, you can do your workout in intervals if you can’t stay in your target zone for 30 minutes. “As your conditioning improves, you will be able to stay longer in your heart rate zone until eventually you can do the entire 30 minutes,” says Dr. Baggish.
Heart Rate Monitoring
You should monitor your fitness activity, workout duration, and heart rate, which is a good idea because you need those numbers to understand your fitness level and objectives.
1. Manual Method:
Find your heart rate without using any assistive devices or pulse monitors. The most common technique is called radial pulse, which is used to find your heart rate by putting your pointer and middle finger on the inside of your opposite wrist. Pulse at the neck and foot can also be checked to calculate your heart rate, but it’s not very common. It’s good to take your pulse a few minutes after your workout starts and also before it ends. This will help you take accurate heart rate readings. Use a stopwatch or any timing device to count your heart rate. Also, count for at least 10 to 15 seconds and you’ll get the idea of your heart rate per minute by multiplying the rate with either six (in case of 10 seconds count) or four (in case of 15 seconds count).
- 25 beats in 10 seconds = 250bpm.
- 15 beats in 15 seconds = 225bpm.
2. Digital Assistive Monitors:
a. Fitness Trackers:
You can use fitness trackers to monitor your heart rate without a problem. Fitness trackers come with different features and specifications. And there may be some stark differences among them. However, you need to choose the one that suits your requirements. It’s better to compare and check features of each fitness tracker to find an accurate one because you’ll need it all the time during your workout. Ideally, you need to monitor your heart rate frequently for the first 30-minute or so. The goal is to make sure your workout level is not too difficult or too easy for your fitness goals. You can then work from there and slow down or push harder, if the need be.
“Forget the gym cardio machine monitors that measure your heart rate when you grab a sensor. They are notoriously inaccurate,” says Dr. Aaron Baggish of Harvard-affiliated Massachusetts General Hospital.
Instead, Baggish recommends a chest strap along with a smartwatch or a fitness tracker for monitoring heart rate. Fitness trackers use sensors that illuminate your blood vessels with the help of an LED light. The sensors then measure the speed with which your blood is being pumped.
b. Chest Strap with a Smartwatch
A chest strap with a wristwatch is used to calculate your heart rate more accurately. Here’s how the combo works:
Chest straps are long, elastic bands that are wrapped around your chest. A transmitter in the chest strap sends electrical signals to your smartwatch through bluetooth. The smartwatch then displays your heart rate in digits.
Which Heart Rate Monitors are Accurate?
When it comes to choosing the right heart rate monitor, the first question you may have is which one is more accurate. Because we don’t want to invest in some sleazy monitors that, though look good, don’t get the job right. So we have different kinds of monitors to pick from.
- Fitness trackers
- Chest strap + wristwatch
Research published in the JAMA Cardiology compared different fitness monitors and found that the most accurate heart rate tracker was chest strap/wristwatch monitor with 99.6% accuracy. Other fitness trackers had an accuracy varied from 92% to 97% and were also off by 15-34bpm.
If you still like simply going with fitness trackers, keep in mind that there may be inconsistencies in their data. So you’ll need to make some necessary adjustments, if possible.
You can find the best fitness monitor for yourself based on the criteria below.
- Type: Monitors that come with chest bands are the most accurate ones for determining heart rate levels. However, those without chest wraps may also be good enough, especially if your basic requirements are anything but heart rate.
- Features: Dozens of new fitness trackers are rolled out every year. It means greater flexibility and innovation in terms of features. To make sure your tracker has the latest features, check out new models.
- Design: Fitness trackers vary based on the design. For example, there are certain monitors that can be used on the wrist as well as neck as a pendant. There are also clip on fitness trackers you can try.
Tips for Exercise in your Target Heart Rate Zones
Now that you’re ready to train with maximum benefits by using your heart rate zone, it’s better to take a step back and evaluate yourself. As we have mentioned earlier that the maximum heart rate may vary for people with different physical fitness, medical history, and gender, etc. For instance, if you’re on medication for any heart condition and want to start heart rate training, consider talking to your physician. He may also help you find your maximum heart rate by factoring in your medical history. For example, your maximum heart rate (with any heart condition) may be lower than the one you find yourself based on the formula. The bottom line: don’t push harder when you’re not required to.
- Find the sweet spot. At first, your aim should be to start training in your target heart rate zone. Then, stay put there for a while before moving on to another zone. Find that sweet spot and stick to it.
- Don’t finish your intense workout abruptly. Don’t quit your workout right after that strenuous strength training. It may backfire. Move gradually from an intense, anaerobic exercise toward an easy, aerobic training.
- Don’t procrastinate in the beginning. At first, it could be overwhelming to make sense of the data and conform with everything your tracker tracks. The best way is to just start and do it consistently.
- Focus on your body: Don’t underestimate your body when it comes to making decisions for your fitness goals. You may see that the data from your trackers may not necessarily be accurate. So better tune in to your body and see if it needs something that your fitness tracker alone can’t find out.
Heart rate training helps you maximize your fitness objectives without overburdening yourself. It means just because you need to lose weight, doesn’t mean you should be doing planks all the time. Unlike traditional training, heart rate based training will help you get ahead of the curve within no time. Though it’s not some quick way to gain muscles and lose weight, the objective-oriented approach to training helps you become better and stronger over time.
All you need is to identify your training heart rate zones, get clear on your goals and start the workout. Based on specific fitness needs, you may want to stay in one zone for some time and then move on to the next zone to further your fitness journey. The idea here’s to not stay in one zone for any longer because we also need to recover from an injury, train at an aerobic level, and reap maximum benefits.
So long as you’re tracking your heart rate zone, exercising regularly and eating the right food, you should be fine.