When it comes to workouts, intensity is key. And the best way to measure it is by monitoring your heart rate. Heart rate zones—the range that reflects your training intensity—allow you to back your workout with science. You might feel like you pushed yourself during 30-minutes of treadmill running, but looking at your heart rate zones can tell you if your perceived rate of exertion actually measures up. Being sweaty and out of breath count towards something, but numbers don’t lie.
Keeping track of your heart rate, and knowing what zone you should be in based on your goals, can help you maximize your workout, as well as spell results. The first step is to calculate your resting heart rate.
Measure Your Resting Heart Rate
Before you hit the tread, make sure that you know your resting heart rate—your heart rate when you’re breathing normally and not exercising. A good rule of thumb: The lower the number, the better. According to Heart.org, the lower your resting heart rate, the better the condition of your heart and the less work it takes to maintain a steady heartbeat. Athletes have been seen to have heart rates around 40 beats per minute (BPM) while a more sedentary life can leave you pushing 100 BPM. For most people, a resting heart rate of anywhere from 60-100 beats per minute is standard.
To check your heart rate, place your index and middle finger on the side of your neck, on your wrists, inside your elbow, or at the top of your foot. Count the number of beats in 60 seconds.
Max Heart Rate
“Your max heart rate is the most beats per minute [that] your heart can beat safely,” says Aaptiv Trainer John Thornhill. Your average max heart rate is 220 minus your age. Knowing your maximum heart rate is important so that you can determine where your heart rate should be based on your exercise intensity. Once you know that, you can gauge where your heart rate should land in the four heart rate zones.
Heart Rate Zones:
There are four different heart zones, based on your maximum heart rate.
Zone 1: 60-70 percent of max heart rate
“Zone one is where your heart rate should be for warming up and walking,” Thornhill says. “If you were having a conversation, you could speak easily and fluidly.”
Zone 2: 70-80 percent of max heart rate
Zone two is still conversational, but you begin to breathe more actively. “Here is where your heart rate will be for low-intensity cardio or strength training,” Thornhill adds.
Zone 3: 80-90 percent of max heart rate
“Zone three can be defined as comfortably challenging, equivalent to tempo training while running, on the elliptical, or cycling,” Thornhill says. If you were having a conversation, you would only be able to say a few short sentences at a time.
Zone 4: 90-100 percent of max heart rate
Zone four is all out max effort. “This zone can also be defined as breathless,” says Thornhill. “You’ll barely be able to say a few words. This zone can only be sustained for, at max, a few minutes at a time.”
What zone should you be in?
“Understanding your heart rate in relation to zones is very useful for exercise purposes to determine what level of physical activity your body can handle,” Thornhill says. “Beginners and people new to fitness should stick to zones one and two while they get acclimated to conditioning. People who are consistently active, or competitive athletes, will benefit from training in zones three and four.”
When it comes to resistance training, Thornhill recommends finding your strength in zone two. Cardio workouts, he says, should fall between zones two and three. One exception he lists: speed training. “If you are training for distance running and looking to improve your time, you may want to include interval training into your routine, with small cardio bursts in zone four,” Thornhill says. One caveat: “if you are pregnant, it’s best to keep your heart rate, when active, under 155 BPM,” he adds.
When measuring heart rate, it’s also important to consider outside factors. While heart rate zone standards are based on age, they can also differ based on other factors, including emotions, air temperature, and even body position. According to Heart.org, your heart rate can increase by a few beats when your emotions are at extremes (happy or sad), as temperatures heat up, and even during the first 15 to 20 seconds of standing.
Your heart rate is the key to better understanding how your body reacts to exercise. Pay attention to it to help you hit those PRs.