Understanding Heart Rate Zones
Heart rate zones are ranges of your heart rate, expressed as a percentage of your maximum heart rate. They are commonly used in fitness and training to guide exercise intensity and ensure you're working at the right level for your goals. There are typically five heart rate zones, each offering different physiological benefits:
- Zone 1 (Very Light): 50-60% of Max Heart Rate. This zone is for active recovery and is very easy.
- Zone 2 (Light): 60-70% of Max Heart Rate. This zone is for building an aerobic base and endurance.
- Zone 3 (Moderate): 70-80% of Max Heart Rate. This zone improves aerobic fitness and is often called the "tempo" zone.
- Zone 4 (Hard): 80-90% of Max Heart Rate. This zone increases anaerobic threshold and power.
- Zone 5 (Maximum): 90-100% of Max Heart Rate. This zone improves speed and performance, but is very intense and short-lived.
The most common way to estimate your maximum heart rate (MHR) is using the formula: 220 – your age.
To calculate your specific heart rate zones, you'll need your estimated maximum heart rate.
function calculateHeartRateZones() {
var age = document.getElementById("age").value;
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
// Input validation
if (age === "" || isNaN(age) || age = 120) {
resultDiv.innerHTML = "Please enter a valid age between 1 and 120.";
return;
}
var maxHeartRate = 220 – parseFloat(age);
var zones = {
zone1: { min: maxHeartRate * 0.50, max: maxHeartRate * 0.60 },
zone2: { min: maxHeartRate * 0.60, max: maxHeartRate * 0.70 },
zone3: { min: maxHeartRate * 0.70, max: maxHeartRate * 0.80 },
zone4: { min: maxHeartRate * 0.80, max: maxHeartRate * 0.90 },
zone5: { min: maxHeartRate * 0.90, max: maxHeartRate * 1.00 }
};
var resultHTML = "
Your Estimated Heart Rate Zones (beats per minute – bpm):
";
resultHTML += "Estimated Maximum Heart Rate: " + Math.round(maxHeartRate) + " bpm";
resultHTML += "
";
resultHTML += "- Zone 1 (Very Light, 50-60%): " + Math.round(zones.zone1.min) + " – " + Math.round(zones.zone1.max) + " bpm
";
resultHTML += "- Zone 2 (Light, 60-70%): " + Math.round(zones.zone2.min) + " – " + Math.round(zones.zone2.max) + " bpm
";
resultHTML += "- Zone 3 (Moderate, 70-80%): " + Math.round(zones.zone3.min) + " – " + Math.round(zones.zone3.max) + " bpm
";
resultHTML += "- Zone 4 (Hard, 80-90%): " + Math.round(zones.zone4.min) + " – " + Math.round(zones.zone4.max) + " bpm
";
resultHTML += "- Zone 5 (Maximum, 90-100%): " + Math.round(zones.zone5.min) + " – " + Math.round(zones.zone5.max) + " bpm
";
resultHTML += "
";
resultHTML += "
Note: This is an estimation. For personalized advice, consult with a healthcare professional or certified trainer.";
resultDiv.innerHTML = resultHTML;
}
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