Not all heart rate maxes are created equal. Here’s how to find your true max.
Why Your Max Heart Rate Is Wrong
And how you can fix it
Depending on your exercise background, you may have maximum heart rate data from many sources. A four day stage race with a huge mountain day, an intense 45 minute criterium, an FTP test on your trainer, a particularly hard workout on Zwift, or a scientifically administered lab test. Combing through your Garmin, TrainingPeaks, TrainerRoad, Strava, or GoldenCheetah data, you’ll see these spikes touted as your maxHR value. They’re used to set your heart rate zones to keep you on track when you’re training. They seem clear and simple, but they may not be that accurate.
Factors Determining Heart Rate
Heart rate is a summative value that’s determined by many factors. Effort has the largest impact on your HR, as your body ramps it up based on need. But ambient temperature, hydration status, excitement (known as arousal in the physiology world), and fatigue all play a role in setting this value. In theory, your max heart rate should be independent of these factors but we all know that’s not the case.
Arousal and HR — The Science
A pair of studies performed on soccer players should large differences between their max heart rates when testing and when playing. Consistently, the players had higher heart rates when they were in games. Their bodies were more aroused and they were able to dig deeper when playing.
The first study, performed on 21 NCAA Division 1 athletes, tested maximum heart rates using a treadmill test and a shuttle run test, then compared those results to max heart rates seen when practicing and playing. Their maximal treadmill heart rates were 7 beats lower than their maximal playing heart rates. That’s enough to significantly shift HR zones around¹.
The other study was performed on 35 professional and college-aged Brazilian athletes and showed similar results. In these athletes, the college-aged players’ max heart rates were 6 beats higher in competition and the professional’s were 11 beats higher. Again, decidedly enough to tweak their heart rate zones². and this paper
Why Max HR Matters
Most people who train with heart rate use their max HRs to determine their heart rate zones. These zones are set as a percentage of maximal heart rate, a common practice in exercise physiology and endurance training. From there, you train within zones, 60–70% of max, etc. Since all future training is based on that maximum, it’s essential to get it right. The table below shows how a 10-beat error in HR max can change your zones.
Setting Your Max HR Correctly
Before you dive into your Garmin or Wahoo and start tweaking your max HR settings, let’s talk about what to do with this information. The most important thing to remember is that training and racing differ. The adrenaline from a race is enough to shove your max HR up. That’s not what you should be using in training. Your max HR is not the maximum that your heart has ever reached. If it were, everyone who has experienced ventricular tachycardia would be setting theirs above 300. Max HR is the value where your heart rate consistently maxes out and won’t go any higher. It shouldn’t be a one-off.
That one 45 minute crit where you sprinted for the second prime, got in a breakaway for the last 15 minutes, and went all out for the win, setting a new max HR along the way? That shouldn’t be the max you set in your Garmin, Wahoo, or Polar device, unless you’re getting close to it all the time. Your max HR, the HR that guides your training, should be set relative to your training. Use values you’ve gotten while on the trainer or local roads.
To find your true max HR, go back through your data and find the highest peaks that don’t correspond to a race day or the time a bear chased you up a climb. That’s the value you should program into your head unit to get the best training effect possible.
Luke is a cycling coach and physiologist from Richmond, VA who rides and races bikes all over the country. He’s an expert on the body in motion and its response to exercise and loves to share his knowledge with others. Find him @LukeHollomon everywhere.
