Heart Rate Zone Calculator

Understanding the 5 Zones

Heart Rate training is about targeting specific physiological adaptations. 1. Zone 1(Recovery) : <60%.Promotes blood flow and active recovery. 2. Zone 2(Endurance Base) : 60 - 70 %.The "Fat Burning" zone.Builds mitochondrial density and capillary networks.You should be able to speak in full sentences. 3. Zone 3(Tempo / Grey Zone) : 70 - 80 %.Often called "junk miles" because it's too hard for recovery but too easy for threshold gains. 4. Zone 4(Threshold) : 80 - 90 %.Improves your ability to clear lactate. "Comfortably hard." 4. Zone 4(Threshold) : 80 - 90 %.Improves your ability to clear lactate. "Comfortably hard." 5. Zone 5(VO2 Max) : 90 - 100 %.Peak aerobic capacity.Can only be held for a few minutes.

💓 Heart Rate Training Zones

| Zone | Intensity(%) | Feeling | Benefit | | : --- | : --- | : --- | : --- | | Zone 1 | 50 - 60 % | Very Easy | Recovery, Warm - up | | Zone 2 ** | ** 60 - 70 %** | ** Conversational ** | ** Base Building, Fat Burn | | Zone 3 | 70 - 80 % | Moderate | Aerobic Capacity(Grey Zone) | | Zone 4 | 80 - 90 % | Hard | Lactate Threshold | | Zone 5 | 90 - 100 % | Maximum | VO2 Max, Anaerobic Speed |

🧮 Max HR vs.Heart Rate Reserve(Karvonen)

* Simple Max HR : 220 - Age. Often inaccurate. * Karvonen Formula**: Uses your **Resting Heart Rate (RHR) to determine your "reserve." * *Formula*: (MaxHR - RHR) * % Intensity + RHR * *Verdict*: Much more accurate for trained individuals.

The 80/20 Rule

Elite endurance athletes spend 80% of their time in Zone 2** and only **20% in Zone 4/5. Spending too much time in Zone 3 leads to stagnation and burnout.