If you don't know your Maximum Heart Rate (MHR), it will be estimated using the formula: 220 – Age.
Understanding the Fat Burning Zone
The fat-burning zone refers to a specific range of heart rate intensity during exercise where your body is estimated to burn a higher percentage of calories from fat. This zone is typically achieved at a moderate intensity.
To calculate your fat-burning zone, we first need to determine your Estimated Maximum Heart Rate (MHR). A common formula for MHR is 220 minus your age.
Once MHR is established, the fat-burning zone is generally considered to be between 60% and 70% of your MHR. For example, if your MHR is 180 bpm, your fat-burning zone would be:
Lower end: 180 bpm * 0.60 = 108 bpm
Upper end: 180 bpm * 0.70 = 126 bpm
Exercising within this zone can be beneficial for endurance and for increasing your body's ability to utilize fat for fuel. However, remember that higher intensity exercise burns more total calories, even if a lower percentage comes from fat. It's important to find an exercise intensity that you can sustain and enjoy.
function calculateFatBurningZone() {
var age = document.getElementById("age").value;
var maxHeartRateInput = document.getElementById("maxHeartRate").value;
var resultDiv = document.getElementById("result");
var fatBurningZoneText = document.getElementById("fatBurningZone");
var fatBurningZonePercentageText = document.getElementById("fatBurningZonePercentage");
if (age === "" || !isNumeric(age) || parseInt(age) 0) {
calculatedMaxHeartRate = parseInt(maxHeartRateInput);
} else {
calculatedMaxHeartRate = 220 – parseInt(age);
if (calculatedMaxHeartRate <= 0) {
alert("The estimated maximum heart rate is not valid based on your age. Please check your age or manually enter your maximum heart rate.");
return;
}
}
var fatBurningLowerBound = calculatedMaxHeartRate * 0.60;
var fatBurningUpperBound = calculatedMaxHeartRate * 0.70;
fatBurningZoneText.textContent = "Your estimated fat-burning heart rate zone is: " + Math.round(fatBurningLowerBound) + " – " + Math.round(fatBurningUpperBound) + " bpm";
fatBurningZonePercentageText.textContent = "(This is approximately 60% to 70% of your maximum heart rate)";
resultDiv.style.display = "block";
}
function isNumeric(value) {
return !isNaN(parseFloat(value)) && isFinite(value);
}