In a world of sports now dominated by copious amounts of data, sometimes it can be beneficial to take a step back and train off of your own internal clock: your heart rate. Heart rate training in this world of technology may feel outdated or old-school, but perhaps it is just what the doctor ordered. There will be days when you simply can not hit your target power numbers on the bike, or your paces during a tempo run no matter how hard you try. In these cases, it can be beneficial to let your heart rate drive the session in order to still get a similar and effective training response to the workout.
If you are new to heart rate training then let this be your guide to ensuring you can get the best out of your workout when using heart rate zones.
What is Heart Rate Training?
First and foremost, let us say this now: your heart rate is unique to you just like a fingerprint. For example, Athlete A’s threshold heart rate may be 180 beats per minute, while Athlete B’s threshold heart rate is 155 beats per minute. Neither the higher or lower number indicates which athlete is in better shape. So before you start comparing heart rate on Strava, always keep this in mind! Heart rate is controlled and influenced by many different variables which we will explain later.
Second key point: You cannot make age-based heart rate calculations. Not every 20 year old or 45 year old will have the same max heart rate, and using this logic can sometimes put individuals at risk for complications if working off of this guiding number. It is always best to have your heart rate lab tested and measured.
Let’s review some cardiac terminology:
Heart Rate: number of times your heart beats per minute, bpm
Resting Heart Rate: your heart rate while you are at rest. Best measured first thing in the morning, or at night.
Max Heart Rate: highest heart rate you can physically obtain
Threshold Heart Rate: refers to the heart rate that you achieve during either threshold power (on the bike) or threshold pace (running.) This heart rate does not have definitive terms as it does of resting or max heart rate. Many different apps, like the SYSTM Training App, use the abbreviation (LTHR) to stand for Lactate Threshold Heart Rate.
Heart Rate Training Zones: ranges of heart rate values that are defined by either an individual’s max heart rate or their threshold heart rate.
How Your Heart Works
Your heart is a four-chambered organ within the circulatory system. The right side of your heart receives blood from the body and pumps it to the lungs for aeration. The left side of the heart receives the oxygenated blood from the lungs and then proceeds to deliver this blood to your body’s tissues. Your blood will function as a signaling system for the heart, any changes within the pH of the blood will alert your heart, due to chemoreceptors. Your body contains hundreds of thousands of receptors that will monitor changes in your body’s internal environment. Any changes to the baseline will cause a cascading effect internally, and will either send signals to the heart to increase or decrease your heart rate. This is important to remember that your heart rate is reactive. It is a response to a change in intensity, so do not be alarmed if you do not immediately hit your threshold heart rate when you just begin an effort, or recovery heart rate when you have just finished an effort.
Why Should I Train With Heart Rate?
When training with heart rate remember to still keep tabs on your own personal RPE (rate of perceived exertion.) Since many different factors can influence your heart rate (sleep, hydration, temperature, caffeine, and stress to name a few.) Recognizing how these variables can affect your heart rate can help you to better understand if your heart rate is higher or lower during a session and whether this is a sign to press on or back off.
Using Heart Rate can be a great tool for recovery days and weeks. Recovery, or “down weeks,” are a crucial part of any training program and should not be overlooked or overworked. Using heart rate can help ensure that you are staying well within easy zones in order to maximize your recovery so that you can hit your next training block hard.
Using heart rate can be an excellent gauge for, “sweet spot,” or long steady efforts where the goal is to remain under your FTP for the entirety of the interval. It is also a good choice to use heart rate when performing endurance or “base” training to make sure you are not pushing too hard.
Using heart rate for short high-intensity efforts will not be the best choice. Why? Your heart rate will not reach its peak most of the time until the effort is already over. The types of efforts this includes will be short duration intervals (less than 4 minutes), high-intensity intervals (anything more than 110% above FTP,) or efforts with constant surging.
Another key takeaway is that heart rate is unique to each activity and testing protocol. For example, having your lactate threshold heart rate taken in a lab for cycling would not be able to translate to your running LTHR. Why? Running utilizes more muscles for movement, which requires more oxygen and therefore would send signals to the heart to increase your heart rate. Therefore your LTRH for running will be higher than in cycling and in turn would change all of your heart rate zones.
Tracking Your Heart Rate
If you are interested in finding your resting heart rate begin by tracking your heart rate every morning or night. You can simply find your heartbeat either on your neck or wrist (thumb side), and count how many beats within 10 seconds. Take this number and multiply it by 6 to figure out how many beats in a 60 second time period. Looking for something a bit more accurate? Check out the line of Tickr heart rate monitors that can easily be used to track all of your training whether on the bike or on the run! Tracking trends in heart rate over time with varying intensity levels is a great way to understand how your body responds to training and when periods of rest and recovery are needed.
If you are looking to figure out your LTHR, then check out the SYSTM Half Monty test. This is a test anyone can perform in the comforts of their own home without having to visit a lab. The test is a cycling test and will consist of a ramp test, where every minute the resistance will become harder (increasing the power based off of your estimated FTP) until failure. After the ramp test and a few minutes of recovery, the test will have you perform a heart rate constrained 20-minute steady effort.
Heart Rate Zones
Even if you have not used heart rate in your training previously, you probably have heard a training partner use the term “zones” before. These zones relate to varying levels of heart rate based off of percentages of either your max heart rate or threshold heart rate.
Zone 1: Active Recovery
Intensity Level: <70% of LT (lactate threshold heart rate) or <55% of FTP (bike power)
Completing activities in zone 1 should feel very easy like you are barely trying. This is where most of your true recovery days should occur!
Zone 2: Endurance
Intensity Level: <70-80% of LT or 55-75% of FTP
Activities in zone 2 should feel like your “all-day pace.”
Zone 3: Tempo
Intensity Level: 87-95% of LT or 75-91% of FTP
Activities in zone 3 are at a pace that you could maintain for a few hours, but you wouldn’t want to be there all day.
Zone 4a: Sub Lactate Threshold
Intensity Level: 95-100% of LT or 91-100% of FTP
Activities in Zone 4a are efforts you could sustain for 60-90 minutes at most
Zone 4b: Supra Lactate Threshold
Intensity Level: 100-105% of LT or 100-110% of FTP
Activities in Zone 4b are efforts you could hold for 30-60 minutes when you are completely fresh. If not fresh…then you would like these efforts to end quickly.
Zone 5: VO2 Max
Intensity Level: 105-MAX% of LT or 110-135% of FTP
Activities in Zone 5 are efforts you could sustain for 3-8 minutes continuously
Zone 6: Anaerobic Capacity / Neuromuscular Power
Intensity Level: N/A or 135-Infinite of FTP
Activities in Zone 6 are all-out efforts such as sprints that last anywhere from 1-30 seconds or stand-alone 3-minute efforts that are a bit more controlled than an all-out sprint
Mac Cassin is the Chief Cycling Physiologist at Wahoo Sports Science. He holds a degree in Integrative Physiology from the University of Colorado-Boulder and has won multiple National Championships. The experience of juggling athletic goals with collegiate and career responsibilities has taught Mac that peak performance is achievable even for those who cannot focus exclusively on training. While concentrating on exercise physiology in an academic setting, Mac competed at the World Championships, Pan American Championships, and World Cups on both the road and track.