This post explains how to get past simplistic and outdated math formulas, and figure out your true heart rate zones for cycling training. To do this, we will explain how to apply the science-based Tanaka and Karvonen formulas to calculate accurate heart rate zones that match your age and your fitness level. That way, you can be sure you are not wasting your time, and ensure you get the training results you want.
If you’re riding regularly and want to get fitter without wasting time, understanding your true heart rate zones is a game-changer. Most of us regularly see our heart rate zones on Garmin, Zwift, or Strava, but have you ever wondered:
“Are these heart rate zones actually correct for me?”
I have definitely asked this question. For example, I try to do a lot of Zone 2 training, and I know that Zone 2 is when you are cycling and can talk, but you cannot sing. Well, last week I was riding with my HR at a level that corresponded to Zone 4, my Threshold Zone, as I could tell from my Garmin watch. But I was still able to talk comfortably to Mrs. Average Joe Cyclist for the entire ride. She said that it was just because nothing can shut me up.
According to my watch, I was riding in my Threshold zone – so how come I was able to talk non-stop to Maggie? This really confused me, and made me question the accuracy of my heart rate training zonesWell, it is possible she is right … but it did cause me to doubt the accuracy of my zones again. So, I went back and pulled all my research together to make sure I was getting it right. Based on all my research, let me show you a smarter, more personalized way to calculate your true heart rate zones. These methods are especially useful if you’re over 40 and fit.
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Step 1: Ditch the Basic “220 Minus Age” Formula
Most apps use:
Max Heart Rate = 220 – age
From this basis, a simple formula is used to derive all of your training heart rate zones. But this formula is both simplistic and outdated, especially for active cyclists. For example, if you’re 50, it gives you a max heart rate of 220 — 50, which is 170 bpm. Or, if you are 65, your max heart rate would be 155.
These numbers are likely to be too low if you are fit, or if you are over 40. If you are both fit and over 40, the numbers could be way too low. That is what turned out to the case for me.
Step 2: Calculate a More Accurate Max Heart Rate Using the Tanaka Formula
The Tanaka Formula is widely considered to be more accurate for measuring the max heart rate of people older than 40.
Tanaka formula →
208 – (0.7 × age)
So if you’re 50:
208 – (0.7 × 50) = 208 – (35) = 173 bpm (as compared to 170 if you use the standard formula)
And if you’re 65:
208 – (0.7 × 65) = 208 – (45.5) = 162.5 bpm (as compared to 155 if you use the standard formula)
As you can see, the difference increases as age increases. This was because the Tanaka study found that “the currently used equation underestimates HRmax in older adults.”
So the Tanaka formula gives you a more accurate max heart rate estimate if you are older.
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Step 3: Use the Karvonen Formula to Find Your Zones
Now let’s personalize your zones using your resting heart rate (you can get this from your Garmin watch or fitness tracker). A lower resting heart rate means you’re fitter, and your zones should reflect that!
At what heart rates should you actually train?
This is where many zone charts become confusing — because they skip the explanation and jump straight to numbers. To avoid that, we’ll use the Karvonen formula, which is one of the most practical ways to calculate personalized heart-rate training zones.
Unlike simple “percent of max HR” charts, Karvonen accounts for resting heart rate, which makes a big difference for fit, active people.
What Is Heart Rate Reserve (and Why Does It Matter)?
The key concept in the Karvonen method is Heart Rate Reserve (HRR).
Heart Rate Reserve is simply the range of heartbeats your heart has available for exercise.
Heart Rate Reserve = Max HR − Resting HR
Think of it as your heart’s usable “engine range” — everything between resting and all-out effort.
The Karvonen Formula (Plain English Version)
The full formula looks like this:
That looks a bit complicated, but conceptually, it’s very simple:
Take a percentage of your heart rate reserve
Then add your resting heart rate back in
That’s it.
Example 1: Fit 50-Year-Old Woman
We’ll assume:
Age: 50
Resting HR: 59 bpm
Fitness level: good
First: Calculate Max HR (Tanaka)
Next: Calculate Heart Rate Reserve
That 114 bpm is the range we’ll use to calculate training zones.
Finally: Calculate Training Zones
Each zone is calculated by taking the relevant percentage of 114 (the heart rate reserve), then adding 59 (the resting heart rate).
| Zone | % Effort | Calculation | Heart Rate |
|---|---|---|---|
| Zone 1 (Recovery) | 50–60% | (114×0.50)+59 → (114×0.60)+59 | 116–127 bpm |
| Zone 2 (Endurance) | 60–70% | (114×0.60)+59 → (114×0.70)+59 | 127–139 bpm |
| Zone 3 (Tempo) | 70–80% | (114×0.70)+59 → (114×0.80)+59 | 139–150 bpm |
| Zone 4 (Threshold) | 80–90% | (114×0.80)+59 → (114×0.90)+59 | 150–162 bpm |
| Zone 5 (VO₂ Max) | 90–100% | (114×0.90)+59 → (114×1.00)+59 | 162–173 bpm |
Example 2: Fit 65-Year-Old Man
Now let’s repeat the exact same process for a second example.
Assumptions:
Age: 65
Resting HR: 59 bpm
Fitness level: good
First: Max HR (Tanaka)
Next: Heart Rate Reserve
Finally: Calculate Training Zones
Each zone is calculated by taking the relevant percentage of 104 (the heart rate reserve), then adding 59 (the resting heart rate).
| Zone | % Effort | Calculation | Heart Rate |
|---|---|---|---|
| Zone 1 (Recovery) | 50–60% | (104×0.50)+59 → (104×0.60)+59 | 111–121 bpm |
| Zone 2 (Endurance) | 60–70% | (104×0.60)+59 → (104×0.70)+59 | 121–132 bpm |
| Zone 3 (Tempo) | 70–80% | (104×0.70)+59 → (104×0.80)+59 | 132–142 bpm |
| Zone 4 (Threshold) | 80–90% | (104×0.80)+59 → (104×0.90)+59 | 142–153 bpm |
| Zone 5 (VO₂ Max) | 90–100% | (104×0.90)+59 → (104×1.00)+59 | 153–163 bpm |
Why Karvonen Works Better for Fit People
Two people can be the same age but have very different resting heart rates. By as many as 40 beats, in some people. Karvonen accounts for that.
Lower resting HR → wider usable range
Higher resting HR → narrower range
This is why Karvonen zones often feel more realistic than simple “percent of max” charts — especially for endurance athletes, cyclists, walkers, and runners who train frequently.
When I use the Tanaka and Karnoven Formulas, my Zone 2 range starts a full 14 beats per minute higher than what I previously assumed. So when I thought I was doing Zone 2 training, I was actually not exercising at all. I was only doing a relaxing recovery spin. Most importantly, when I thought I was in Threshold zone (Zone 4), I was actually still in Zone 2. No wonder I could still talk non-stop. It had nothing to do with my inability to shut myself up!
The Most Important Zone: Zone 2
Regardless of your age, Zone 2:
Feels easy but not lazy, so it is sustainable for long sessions
Allows full-sentence conversation
Builds aerobic endurance
Improves fat metabolism
The most important impacts of Zone 2 happen “under the hood,” but are hugely important. For a start, it builds the capillary network in your muscles, so they become more efficient. Also, it builds the mitochondria, which are known as the powerhouses of your cells. Growing more mitochondria, and improving the ones you already have, is good because this increases their ability to burn fat and produce energy efficiently using oxygen. This in turn boosts endurance and reduces stress on your body, so you can ride for longer and then recover faster. And ultimately, actually age better.
If you only get one zone right, make it this one!
Zone 2 rides are fun and relaxing, and yield multiple health and fitness benefits. And you can talk as well!Key Takeaway for Figuring Out Your True Heart Rate Zones for Cycling Training
To calculate accurate heart-rate training zones:
Use Tanaka to estimate max HR
Subtract resting HR to get heart rate reserve
Apply the Karvonen formula
Let the math guide you — not generic charts
Once you understand where the numbers come from, heart-rate training stops feeling arbitrary and starts making sense.
Final Thoughts
Getting fitter doesn’t mean riding harder all the time. It means riding smarter—and that starts with knowing your real heart rate zones.
Whether you’re training for a century ride, working on endurance, or just burning fat, using these personalized zones with your favorite tech tools will give you better results, faster recovery, and fewer setbacks.
You’ve already got the passion—now you’ve got the numbers to back it up.
Ride on!
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Other Useful Posts to Help You Fine Tune Your Cycling Training
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Related Post: The Best Cycling Workouts for Longevity: Why Zone 2 Might Be the Most Powerful Ride of Your Life
Related Post: Complete Guide to Using Power Zones for Cycling Training
Related Post: Stop Spinning Your Wheels: How Cycling Training Zones Can Take You From Casual Rider to Race-Ready
Sources Used in this Post:
Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001 Jan;37(1):153-6. doi: 10.1016/s0735-1097(00)01054-8. PMID: 11153730.
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