Understand your training intensity by calculating your heart rate zones.
Your Heart Rate Zones:
Zone 1 (Very Light): Recovery, warm-up, cool-down.
Zone 2 (Light): Aerobic base building, fat burning.
Zone 3 (Moderate): Improving aerobic fitness and endurance.
Zone 4 (Hard): Improving speed and anaerobic threshold.
Zone 5 (Maximum): Peak performance, high-intensity intervals.
function calculateHeartRateZones() {
var age = document.getElementById("age").value;
var restingHeartRate = document.getElementById("restingHeartRate").value;
var ageError = document.getElementById("age");
var restingHeartRateError = document.getElementById("restingHeartRate");
// Clear previous error messages
ageError.style.borderColor = "#ccc";
restingHeartRateError.style.borderColor = "#ccc";
if (age === "" || isNaN(age) || age <= 0) {
alert("Please enter a valid age.");
ageError.style.borderColor = "red";
return;
}
if (restingHeartRate === "" || isNaN(restingHeartRate) || restingHeartRate <= 0) {
alert("Please enter a valid resting heart rate.");
restingHeartRateError.style.borderColor = "red";
return;
}
age = parseFloat(age);
restingHeartRate = parseFloat(restingHeartRate);
// Karvonen Formula
var maxHeartRate = 220 – age;
var heartRateReserve = maxHeartRate – restingHeartRate;
// Zone 1: 50-60% of HRR
var zone1Min = Math.round((0.50 * heartRateReserve) + restingHeartRate);
var zone1Max = Math.round((0.60 * heartRateReserve) + restingHeartRate);
// Zone 2: 60-70% of HRR
var zone2Min = Math.round((0.60 * heartRateReserve) + restingHeartRate);
var zone2Max = Math.round((0.70 * heartRateReserve) + restingHeartRate);
// Zone 3: 70-80% of HRR
var zone3Min = Math.round((0.70 * heartRateReserve) + restingHeartRate);
var zone3Max = Math.round((0.80 * heartRateReserve) + restingHeartRate);
// Zone 4: 80-90% of HRR
var zone4Min = Math.round((0.80 * heartRateReserve) + restingHeartRate);
var zone4Max = Math.round((0.90 * heartRateReserve) + restingHeartRate);
// Zone 5: 90-100% of HRR
var zone5Min = Math.round((0.90 * heartRateReserve) + restingHeartRate);
var zone5Max = Math.round((1.00 * heartRateReserve) + restingHeartRate);
// Ensure zone limits don't exceed maxHeartRate
zone5Max = Math.min(zone5Max, maxHeartRate);
document.getElementById("zone1").innerHTML = "Zone 1: " + zone1Min + " – " + zone1Max + " BPM";
document.getElementById("zone2").innerHTML = "Zone 2: " + zone2Min + " – " + zone2Max + " BPM";
document.getElementById("zone3").innerHTML = "Zone 3: " + zone3Min + " – " + zone3Max + " BPM";
document.getElementById("zone4").innerHTML = "Zone 4: " + zone4Min + " – " + zone4Max + " BPM";
document.getElementById("zone5").innerHTML = "Zone 5: " + zone5Min + " – " + zone5Max + " BPM";
}
Understanding Heart Rate Zones
Heart rate zones are ranges of heartbeats per minute (BPM) that correspond to different levels of exercise intensity. Training within specific heart rate zones helps you achieve various fitness goals, whether it's improving cardiovascular health, burning fat, or enhancing athletic performance.
How to Calculate Your Heart Rate Zones
The most common method for calculating heart rate zones uses your age to estimate your maximum heart rate and then factors in your resting heart rate using the Karvonen Formula.
1. Estimate Maximum Heart Rate (MHR)
A simple and widely used formula to estimate your maximum heart rate is:
MHR = 220 - Age
For example, if you are 30 years old, your estimated MHR is 220 – 30 = 190 BPM.
2. Measure Your Resting Heart Rate (RHR)
Your resting heart rate is the number of times your heart beats per minute when you are completely at rest. The best time to measure this is first thing in the morning before you get out of bed. For accuracy, measure it for a full minute and take the average over a few days. A typical resting heart rate for adults is between 60 and 100 BPM.
3. Calculate Heart Rate Reserve (HRR)
Heart Rate Reserve is the difference between your Maximum Heart Rate and your Resting Heart Rate.
HRR = MHR - RHR
Using our example of a 30-year-old with an RHR of 60 BPM:
HRR = 190 BPM - 60 BPM = 130 BPM
4. Determine Your Heart Rate Zones
Now, you can calculate your five heart rate training zones using your HRR and RHR. The percentages below represent a percentage of your Heart Rate Reserve added to your Resting Heart Rate.
Zone 1 (50-60% of HRR): Recovery and light warm-up/cool-down.
Zone 2 (60-70% of HRR): Light intensity, building aerobic base, good for fat burning.
Zone 3 (70-80% of HRR): Moderate intensity, improving aerobic fitness and endurance.
Zone 4 (80-90% of HRR): Hard intensity, improving speed and anaerobic threshold.
Zone 5 (90-100% of HRR): Maximum intensity, for peak performance and very short, high-intensity intervals.
Using the Karvonen Formula and our example (Age 30, RHR 60, MHR 190, HRR 130):
Zone 1: 50-60% of 130 + 60 = 65-78 + 60 = 125 – 138 BPM
Zone 2: 60-70% of 130 + 60 = 78-91 + 60 = 138 – 151 BPM
Zone 3: 70-80% of 130 + 60 = 91-104 + 60 = 151 – 164 BPM
Zone 4: 80-90% of 130 + 60 = 104-117 + 60 = 164 – 177 BPM
Zone 5: 90-100% of 130 + 60 = 117-130 + 60 = 177 – 190 BPM
Remember, these are estimates. Individual responses to exercise can vary. It's always a good idea to consult with a healthcare professional or a certified fitness trainer before starting a new exercise program.