#heart-rate-zones-calculator {
font-family: Arial, sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 600px;
margin: 20px auto;
background-color: #f9f9f9;
}
#heart-rate-zones-calculator h2 {
text-align: center;
color: #333;
margin-bottom: 20px;
}
.input-group {
margin-bottom: 15px;
display: flex;
align-items: center;
justify-content: space-between;
}
.input-group label {
display: inline-block;
margin-right: 10px;
color: #555;
min-width: 150px; /* Ensure labels are aligned */
}
.input-group input[type="number"],
.input-group input[type="text"] {
padding: 8px;
border: 1px solid #ccc;
border-radius: 4px;
width: 100px; /* Fixed width for input fields */
box-sizing: border-box;
}
button {
display: block;
width: 100%;
padding: 10px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
cursor: pointer;
margin-top: 20px;
}
button:hover {
background-color: #0056b3;
}
#results {
margin-top: 25px;
padding-top: 15px;
border-top: 1px solid #eee;
color: #333;
}
#results h3 {
margin-bottom: 15px;
color: #007bff;
}
#results p {
margin-bottom: 8px;
}
.zone {
font-weight: bold;
}
function calculateHeartRateZones() {
var age = parseFloat(document.getElementById("age").value);
var restingHeartRate = parseFloat(document.getElementById("restingHeartRate").value);
var maxHeartRate = parseFloat(document.getElementById("maxHeartRate").value);
var errorMessages = "";
var resultsDiv = document.getElementById("results");
// Clear previous messages
document.getElementById("zone1").innerHTML = "";
document.getElementById("zone2").innerHTML = "";
document.getElementById("zone3").innerHTML = "";
document.getElementById("zone4").innerHTML = "";
document.getElementById("zone5").innerHTML = "";
document.getElementById("errorMessages").innerHTML = "";
// Input validation
if (isNaN(age) || age 120) {
errorMessages += "Please enter a valid age between 1 and 120 years.";
}
if (isNaN(restingHeartRate) || restingHeartRate 200) {
errorMessages += "Please enter a valid resting heart rate between 30 and 200 bpm.";
}
if (isNaN(maxHeartRate) || maxHeartRate 220) {
errorMessages += "Please enter a valid estimated or measured maximum heart rate between 100 and 220 bpm.";
}
// If there are errors, display them and stop
if (errorMessages !== "") {
document.getElementById("errorMessages").innerHTML = errorMessages;
return;
}
// If max heart rate is not provided, estimate it using Tanaka's formula (208 – 0.7 * age)
// However, the prompt requires a maxHeartRate input, so we'll use it if provided.
// If you want to use the estimation *only* if the field is empty, you'd add:
// if (isNaN(maxHeartRate) || maxHeartRate <= 0) {
// maxHeartRate = 208 – 0.7 * age;
// if (maxHeartRate 220) maxHeartRate = 220;
// }
// Calculation of Heart Rate Reserve (HRR)
var heartRateReserve = maxHeartRate – restingHeartRate;
// Calculate zones based on Karvonen formula (uses HRR) and common percentage guidelines
// Zone 1: Very Light (50-60% of HRR + RHR)
var zone1_lower = Math.round((heartRateReserve * 0.50) + restingHeartRate);
var zone1_upper = Math.round((heartRateReserve * 0.60) + restingHeartRate);
// Zone 2: Light (60-70% of HRR + RHR)
var zone2_lower = Math.round((heartRateReserve * 0.60) + restingHeartRate);
var zone2_upper = Math.round((heartRateReserve * 0.70) + restingHeartRate);
// Zone 3: Moderate (70-80% of HRR + RHR)
var zone3_lower = Math.round((heartRateReserve * 0.70) + restingHeartRate);
var zone3_upper = Math.round((heartRateReserve * 0.80) + restingHeartRate);
// Zone 4: Hard (80-90% of HRR + RHR)
var zone4_lower = Math.round((heartRateReserve * 0.80) + restingHeartRate);
var zone4_upper = Math.round((heartRateReserve * 0.90) + restingHeartRate);
// Zone 5: Maximum (90-100% of HRR + RHR)
var zone5_lower = Math.round((heartRateReserve * 0.90) + restingHeartRate);
var zone5_upper = maxHeartRate; // Use actual max HR as upper limit
// Ensure zones don't exceed Max Heart Rate
zone1_upper = Math.min(zone1_upper, maxHeartRate);
zone2_upper = Math.min(zone2_upper, maxHeartRate);
zone3_upper = Math.min(zone3_upper, maxHeartRate);
zone4_upper = Math.min(zone4_upper, maxHeartRate);
zone5_upper = Math.min(zone5_upper, maxHeartRate);
// Ensure lower bounds are not below resting heart rate or upper bounds
zone1_lower = Math.max(zone1_lower, restingHeartRate);
zone2_lower = Math.max(zone2_lower, zone1_upper); // Ensure no overlap
zone3_lower = Math.max(zone3_lower, zone2_upper);
zone4_lower = Math.max(zone4_lower, zone3_upper);
zone5_lower = Math.max(zone5_lower, zone4_upper);
// Display results
document.getElementById("zone1").innerHTML = "Zone 1 (Recovery/Very Light): " + zone1_lower + " – " + zone1_upper + " bpm";
document.getElementById("zone2").innerHTML = "Zone 2 (Endurance/Light): " + zone2_lower + " – " + zone2_upper + " bpm";
document.getElementById("zone3").innerHTML = "Zone 3 (Tempo/Moderate): " + zone3_lower + " – " + zone3_upper + " bpm";
document.getElementById("zone4").innerHTML = "Zone 4 (Threshold/Hard): " + zone4_lower + " – " + zone4_upper + " bpm";
document.getElementById("zone5").innerHTML = "Zone 5 (Maximum/Very Hard): " + zone5_lower + " – " + zone5_upper + " bpm";
}
Heart Rate Running Zones Calculator
Your Heart Rate Training Zones:
Understanding Heart Rate Training Zones for Running
Heart rate training zones are a crucial tool for runners looking to optimize their training, improve performance, and enhance recovery. By training within specific heart rate ranges, you can target different physiological systems and ensure you're working at the right intensity for your goals.
How It Works
These zones are typically calculated based on your maximum heart rate (MHR) and resting heart rate (RHR). The Karvonen formula, which uses your Heart Rate Reserve (HRR), is a popular and effective method. HRR is the difference between your MHR and RHR (HRR = MHR – RHR). Your training zones are then expressed as a percentage of this reserve, plus your RHR.
The Zones Explained
- Zone 1 (50-60% of HRR + RHR): This is your recovery zone. Effort is very light, and you can easily hold a conversation. It's ideal for active recovery days, cooling down, or very light aerobic work.
- Zone 2 (60-70% of HRR + RHR): Known as the endurance zone. This is where you build your aerobic base. You can talk in short sentences. Most of your running, especially long runs, should be in this zone to improve your body's ability to use fat for fuel and build endurance.
- Zone 3 (70-80% of HRR + RHR): The tempo or moderate zone. You can speak in single words. This zone improves your aerobic capacity and lactate threshold, making you more efficient at faster paces.
- Zone 4 (80-90% of HRR + RHR): This is the threshold or hard zone. Speaking is difficult. Training here significantly improves your lactate threshold, allowing you to sustain faster paces for longer. It's often used for race pace work.
- Zone 5 (90-100% of HRR + RHR): The maximum or very hard zone. Breathing is heavy, and talking is impossible. This zone is for very short, intense bursts of effort to maximize VO2 max and speed. It requires significant recovery.
Important Considerations
- Maximum Heart Rate: Your maximum heart rate can be estimated using formulas like 220 – age (a very general estimate) or Tanaka's formula (208 – 0.7 * age). However, the most accurate way is through a lab test or a field test conducted by a professional. Using a measured MHR will yield more accurate zones.
- Resting Heart Rate: Measure your RHR first thing in the morning before getting out of bed for the most accurate reading.
- Individual Variation: These are guidelines. Listen to your body. Factors like fatigue, hydration, and temperature can affect your heart rate.
Using this calculator will help you identify these critical zones, allowing you to structure your training runs effectively to meet your running goals, whether it's building endurance, improving speed, or recovering efficiently.
Example: For a 30-year-old with a resting heart rate of 60 bpm and a measured maximum heart rate of 190 bpm:
- Age: 30
- Resting Heart Rate: 60 bpm
- Max Heart Rate: 190 bpm
- Heart Rate Reserve (HRR) = 190 – 60 = 130 bpm
- Zone 1 (50-60%): (130 * 0.50) + 60 = 125 bpm to (130 * 0.60) + 60 = 138 bpm
- Zone 2 (60-70%): (130 * 0.60) + 60 = 138 bpm to (130 * 0.70) + 60 = 151 bpm
- Zone 3 (70-80%): (130 * 0.70) + 60 = 151 bpm to (130 * 0.80) + 60 = 164 bpm
- Zone 4 (80-90%): (130 * 0.80) + 60 = 164 bpm to (130 * 0.90) + 60 = 177 bpm
- Zone 5 (90-100%): (130 * 0.90) + 60 = 177 bpm to 190 bpm