💓 Heart Rate Reserve Calculator

Use the Karvonen method to calculate a personalized training heart rate from your age and resting heart rate. FitnessView uses this kind of data to make zone-based training feel a lot less guessy.

Formula: Target HR = resting HR + ((max HR - resting HR) × intensity)

Calculator

Zone 1: 50-60% HRR | Zone 2: 60-70% | Zone 3: 70-80% | Zone 4: 80-90% | Zone 5: 90-100%

Age

Resting HR (bpm)

Intensity %

Why This Matters

Heart rate reserve is better than a straight max-heart-rate percentage for a lot of people because it accounts for your resting baseline. That makes the target feel more personal and less generic.

If your resting heart rate changes with stress, sleep, or training block load, the target can move too. That is useful, because your body does not train in a vacuum.

Reference Ranges

      Quick read: Zone 1: 50-60% HRR | Zone 2: 60-70% | Zone 3: 70-80% | Zone 4: 80-90% | Zone 5: 90-100%
    

Example Calculations

Input	Result
Age 30, resting HR 60, 70% effort	Target heart rate: 151 bpm
Age 45, resting HR 55, 65% effort	Target heart rate: 139 bpm

How FitnessView Helps

FitnessView can show your workout averages, HR trend lines, and how often you are landing in the right zone for the day.

That makes it easy to keep easy days easy and hard days honest.

Tips

Use a resting heart rate taken first thing in the morning for the cleanest estimate.
If you are returning from a break, start with Zone 2 before pushing into threshold work.
Compare the result to your Apple Watch workout averages in FitnessView.
Recalculate whenever your resting heart rate shifts for more than a couple of weeks.

Frequently Asked Questions

Which max heart rate formula does this use?

It uses the common 220 minus age estimate so the math stays simple. If you have a better measured max HR, swap that in and the result becomes even more useful.

Is resting HR important?

Yes. A lower resting HR usually pushes the same percentage effort to a slightly different bpm target than someone with a higher resting HR.

Can I use this with Apple Watch?

Yes. Use your watch for the actual workout and compare the live or post-workout numbers in FitnessView.

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