Understanding Target Heart Rate
Your target heart rate is a range of heartbeats per minute that is recommended during aerobic exercise. It's a crucial metric for ensuring you're exercising at an intensity that is safe and effective for your fitness goals. Exercising within your target heart rate zone helps improve cardiovascular health, burn calories efficiently, and enhance endurance.
How to Calculate Your Target Heart Rate
There are a couple of common methods to estimate your target heart rate. The most widely used involves calculating your maximum heart rate and then determining a percentage of that maximum.
1. Estimating Maximum Heart Rate:
A simple formula to estimate your maximum heart rate (the highest your heart should beat during intense exercise) is:
220 – Age
2. Karvonen Formula (Heart Rate Reserve Method):
This method is often considered more accurate as it takes your resting heart rate into account. It uses your Heart Rate Reserve (HRR), which is the difference between your maximum heart rate and your resting heart rate.
Heart Rate Reserve (HRR) = Maximum Heart Rate – Resting Heart Rate
Then, to find your target heart rate at a specific intensity (e.g., 85% of your HRR):
Target Heart Rate = (HRR * Intensity %) + Resting Heart Rate
For example, if you are 30 years old, have a resting heart rate of 65 bpm, and want to train at 85% of your heart rate reserve:
- Maximum Heart Rate = 220 – 30 = 190 bpm
- Heart Rate Reserve (HRR) = 190 – 65 = 125 bpm
- Target Heart Rate = (125 * 0.85) + 65 = 106.25 + 65 = 171.25 bpm
This calculator uses the Karvonen formula to provide a more personalized target heart rate zone. The "Maximum Heart Rate (%)" input allows you to specify the desired intensity level for your workout.
Understanding Target Heart Rate Zones:
- Moderate Intensity: Typically 50-70% of your maximum heart rate. You can talk but not sing.
- Vigorous Intensity: Typically 70-85% of your maximum heart rate. You can only say a few words without pausing for breath.
Always consult with a healthcare professional before starting any new exercise program.
function calculateTargetHeartRate() {
var age = document.getElementById("age").value;
var restingHeartRate = document.getElementById("restingHeartRate").value;
var maxHeartRatePercentage = document.getElementById("maxHeartRate").value;
var resultDiv = document.getElementById("result");
// Clear previous results
resultDiv.innerHTML = "";
// Input validation
if (age === "" || restingHeartRate === "" || maxHeartRatePercentage === "") {
resultDiv.innerHTML = "Please fill in all fields.";
return;
}
age = parseInt(age);
restingHeartRate = parseInt(restingHeartRate);
maxHeartRatePercentage = parseInt(maxHeartRatePercentage);
if (isNaN(age) || isNaN(restingHeartRate) || isNaN(maxHeartRatePercentage)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (age <= 0 || restingHeartRate <= 0 || maxHeartRatePercentage 100) {
resultDiv.innerHTML = "Please enter valid positive numbers. For percentage, use a value between 1 and 100.";
return;
}
// Calculate Maximum Heart Rate (MHR)
var maxHeartRate = 220 – age;
// Calculate Heart Rate Reserve (HRR)
var heartRateReserve = maxHeartRate – restingHeartRate;
// Handle edge case where resting heart rate might be higher than calculated max heart rate
if (heartRateReserve < 0) {
heartRateReserve = 0; // Or display an error, depending on desired behavior
}
// Calculate Target Heart Rate
var targetHeartRate = (heartRateReserve * (maxHeartRatePercentage / 100)) + restingHeartRate;
// Ensure target heart rate is not negative (though unlikely with valid inputs)
if (targetHeartRate < 0) {
targetHeartRate = 0;
}
resultDiv.innerHTML = "
Your Target Heart Rate:
" +
"Estimated Maximum Heart Rate:
" + maxHeartRate.toFixed(0) + " bpm" +
"Heart Rate Reserve:
" + heartRateReserve.toFixed(0) + " bpm" +
"At " + maxHeartRatePercentage + "% of your heart rate reserve, your target heart rate is approximately:
" + targetHeartRate.toFixed(0) + " bpm";
}
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