Heart Rate Zones
Your five training zones based on maximum heart rate. Reframed as a baseline for tracking progress, not a target to force yourself into.
Your details
Adding your resting HR uses the Karvonen method for more personalized zones.
Your Heart Rate Zones
Why Zone 2 matters most
Zone 2 is where fat oxidation is highest and your aerobic base is built. It should feel like you can hold a conversation but not sing. For most people, this is the zone with the highest return on time invested. Progress means your Zone 2 ceiling rises over weeks and months as your cardiovascular fitness improves.
What this means
These zones represent your estimated heart rate ranges for different exercise intensities. They are calculated from your age-predicted maximum heart rate. Your zones are a starting point for understanding effort levels, not rigid boundaries.
What to consider
Track your zones over time rather than treating them as fixed targets. As your fitness improves, you will be able to do more work at lower heart rates. That shift is one of the clearest signals of cardiovascular progress. If you are new to heart rate training, start by simply noticing which zone you are in during your usual activities.
Medications that may affect your zones
Beta-blockers (metoprolol, atenolol, propranolol) significantly lower both maximum heart rate and resting heart rate. If you are on a beta-blocker, your actual zones will be substantially different from these estimates. Heart rate-based zone calculations are unreliable on beta-blocker therapy. Consider using Rate of Perceived Exertion (RPE) instead.
Calcium channel blockers (diltiazem, verapamil) can also lower heart rate, though typically less than beta-blockers.
Stimulant medications (ADHD medications, decongestants) may elevate resting heart rate, which can shift your Karvonen zones.
If you are on heart rate-affecting medications, discuss training zones with your healthcare provider. RPE-based training may be more appropriate.
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About this tool
Formulas
Standard method: Max HR = 220 - age. Zones calculated as percentages of max HR.
Karvonen method (when resting HR is provided): Target HR = ((Max HR - Resting HR) × intensity%) + Resting HR. This method accounts for individual fitness level through resting heart rate.
Zone Definitions
Zone 1 (50-60%): Recovery, warm-up, cool-down. Zone 2 (60-70%): Aerobic base, fat oxidation, conversational pace. Zone 3 (70-80%): Tempo, moderate effort. Zone 4 (80-90%): Threshold, hard effort, limited conversation. Zone 5 (90-100%): Maximum effort, short bursts only.
Known Limitations
220 minus age is a population average with a standard deviation of ±10-20 bpm. Individual max HR varies significantly and decreases with age in a non-linear way. The formula becomes less accurate at older ages. Not appropriate as a hard training target for people on cardiac medications. A proper max HR test with a healthcare provider is the most accurate alternative.
Sources
Fox SM, et al. "Physical activity and the prevention of coronary heart disease." 1971 (220-age formula). Karvonen MJ, et al. "The effects of training on heart rate." 1957.
Educational tool only. Not for diagnostic purposes. Consult a healthcare provider for medical decisions.