Calculating Zone Heart Rates

by

This calculator helps you determine your heart rate zones for training, based on your maximum heart rate (MHR) and resting heart rate (RHR).

function calculateHeartRateZones() { var age = document.getElementById("age").value; var restingHeartRate = document.getElementById("restingHeartRate").value; var resultDiv = document.getElementById("heartRateZonesResult"); resultDiv.innerHTML = ""; // Clear previous results if (isNaN(age) || age 100) { resultDiv.innerHTML = "Please enter a valid age between 1 and 100."; return; } if (isNaN(restingHeartRate) || restingHeartRate = 220) { resultDiv.innerHTML = "Please enter a valid resting heart rate between 1 and 220 bpm."; return; } // Karvonen Formula for Maximum Heart Rate (MHR) approximation // A common and simple estimation is 220 – age var maxHeartRate = 220 – age; // Heart Rate Reserve (HRR) var heartRateReserve = maxHeartRate – restingHeartRate; var zones = {}; // Zone 1: Very Light (50-60% of HRR) zones["Zone 1 (Very Light)"] = { lower: Math.round(restingHeartRate + (0.50 * heartRateReserve)), upper: Math.round(restingHeartRate + (0.60 * heartRateReserve)) }; // Zone 2: Light (60-70% of HRR) zones["Zone 2 (Light)"] = { lower: Math.round(restingHeartRate + (0.60 * heartRateReserve)), upper: Math.round(restingHeartRate + (0.70 * heartRateReserve)) }; // Zone 3: Moderate (70-80% of HRR) zones["Zone 3 (Moderate)"] = { lower: Math.round(restingHeartRate + (0.70 * heartRateReserve)), upper: Math.round(restingHeartRate + (0.80 * heartRateReserve)) }; // Zone 4: Hard (80-90% of HRR) zones["Zone 4 (Hard)"] = { lower: Math.round(restingHeartRate + (0.80 * heartRateReserve)), upper: Math.round(restingHeartRate + (0.90 * heartRateReserve)) }; // Zone 5: Maximum (90-100% of HRR) zones["Zone 5 (Maximum)"] = { lower: Math.round(restingHeartRate + (0.90 * heartRateReserve)), upper: maxHeartRate // Upper bound is MHR }; var resultHTML = "

Your Heart Rate Zones:

"; resultHTML += "Estimated Maximum Heart Rate (MHR): " + maxHeartRate + " bpm"; resultHTML += "Heart Rate Reserve (HRR): " + heartRateReserve + " bpm"; resultHTML += "
    "; for (var zoneName in zones) { resultHTML += "
  • " + zoneName + ": " + zones[zoneName].lower + " – " + zones[zoneName].upper + " bpm
    • "; } resultHTML += "
"; resultDiv.innerHTML = resultHTML; }

Understanding Heart Rate Training Zones

Heart rate training zones are ranges of your maximum heart rate (MHR) that correspond to different levels of exercise intensity. Training within these zones allows you to optimize your workouts for specific goals, whether it's building endurance, improving cardiovascular health, burning fat, or increasing speed and power.

Estimating Your Maximum Heart Rate (MHR)

The most common and straightforward method to estimate your MHR is the 220 minus your age formula. While this is a general guideline and individual variations exist, it provides a good starting point for calculating your training zones. For example, if you are 30 years old, your estimated MHR would be 220 – 30 = 190 bpm.

The Karvonen Formula and Heart Rate Reserve (HRR)

For a more personalized approach, the Karvonen formula takes into account your resting heart rate (RHR) to calculate your Heart Rate Reserve (HRR). The HRR is the difference between your MHR and your RHR. It represents the range of your heart rate that is available for exercise.

The formula for HRR is: HRR = MHR – RHR.

Once you have your HRR, you can calculate the heart rate for each zone by applying a percentage of your HRR to your RHR:

Target Heart Rate = (HRR × % Intensity) + RHR

The Five Heart Rate Training Zones

These zones are typically divided into five levels, each offering distinct physiological benefits:

  • Zone 1 (Very Light – 50-60% of HRR): This is an active recovery zone. It's ideal for warm-ups, cool-downs, and very light activity. It helps improve blood flow and reduce muscle soreness without causing significant stress.
  • Zone 2 (Light – 60-70% of HRR): This is your aerobic or endurance zone. You can sustain activity in this zone for extended periods. It's excellent for building aerobic capacity, improving endurance, and promoting fat burning. You should be able to hold a conversation comfortably.
  • Zone 3 (Moderate – 70-80% of HRR): This zone is often referred to as the "tempo" or "steady-state" zone. It improves aerobic fitness and increases lactate threshold, meaning your body becomes more efficient at clearing lactic acid. Conversations become more challenging, with shorter sentences.
  • Zone 4 (Hard – 80-90% of HRR): This is your anaerobic or threshold zone. It significantly improves your speed and power and raises your lactate threshold. You can only speak in very short phrases. Training here is intense and should be performed for shorter durations.
  • Zone 5 (Maximum – 90-100% of HRR): This zone represents maximum effort and is primarily for short bursts of very high-intensity exercise. It pushes your cardiovascular system to its limits and is crucial for improving performance in competitive events. You cannot speak more than a word or two.

Example Calculation

Let's calculate the zones for a 40-year-old individual with a resting heart rate of 65 bpm.

  • Age: 40 years
  • Resting Heart Rate (RHR): 65 bpm
  • Estimated Maximum Heart Rate (MHR): 220 – 40 = 180 bpm
  • Heart Rate Reserve (HRR): 180 – 65 = 115 bpm

Using the Karvonen formula:

  • Zone 1 (50-60%): (115 × 0.50) + 65 = 57.5 + 65 = 122.5 bpm to (115 × 0.60) + 65 = 69 + 65 = 134 bpm. Rounded: 123 – 134 bpm.
  • Zone 2 (60-70%): (115 × 0.60) + 65 = 69 + 65 = 134 bpm to (115 × 0.70) + 65 = 80.5 + 65 = 145.5 bpm. Rounded: 134 – 146 bpm.
  • Zone 3 (70-80%): (115 × 0.70) + 65 = 80.5 + 65 = 145.5 bpm to (115 × 0.80) + 65 = 92 + 65 = 157 bpm. Rounded: 146 – 157 bpm.
  • Zone 4 (80-90%): (115 × 0.80) + 65 = 92 + 65 = 157 bpm to (115 × 0.90) + 65 = 103.5 + 65 = 168.5 bpm. Rounded: 157 – 169 bpm.
  • Zone 5 (90-100%): (115 × 0.90) + 65 = 103.5 + 65 = 168.5 bpm to 180 bpm. Rounded: 169 – 180 bpm.

By inputting your age and resting heart rate into the calculator above, you can quickly determine your personalized heart rate training zones. Remember to listen to your body and consult with a healthcare professional or certified trainer if you have any concerns.

Leave a Comment