/* General Styles for WordPress Compatibility */
.hr-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #fff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.hr-calculator-header {
text-align: center;
margin-bottom: 25px;
color: #2c3e50;
}
.hr-input-group {
margin-bottom: 20px;
}
.hr-input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #34495e;
}
.hr-input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box; /* Fix padding issues */
}
.hr-input-group input:focus {
border-color: #3498db;
outline: none;
}
.hr-btn-calculate {
display: block;
width: 100%;
padding: 15px;
background-color: #e74c3c;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background 0.3s;
}
.hr-btn-calculate:hover {
background-color: #c0392b;
}
.hr-results {
margin-top: 30px;
padding: 20px;
background-color: #f9f9f9;
border-radius: 6px;
display: none; /* Hidden by default */
border-left: 5px solid #e74c3c;
}
.hr-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 15px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.hr-result-row:last-child {
border-bottom: none;
margin-bottom: 0;
}
.hr-result-label {
font-weight: 600;
color: #555;
}
.hr-result-value {
font-weight: bold;
color: #2c3e50;
font-size: 1.1em;
}
.hr-zone-card {
background: #fff;
padding: 15px;
margin-top: 15px;
border-radius: 4px;
border: 1px solid #eee;
}
.hr-zone-title {
color: #e74c3c;
font-weight: bold;
margin-bottom: 5px;
}
.hr-zone-desc {
font-size: 0.9em;
color: #666;
}
/* Content Article Styles */
.hr-article-content {
max-width: 800px;
margin: 40px auto 0;
line-height: 1.6;
color: #333;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.hr-article-content h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #ecf0f1;
padding-bottom: 10px;
}
.hr-article-content h3 {
color: #34495e;
margin-top: 25px;
}
.hr-article-content p {
margin-bottom: 15px;
}
.hr-article-content ul {
margin-bottom: 20px;
padding-left: 20px;
}
.hr-article-content li {
margin-bottom: 10px;
}
.hr-highlight-box {
background-color: #e8f6f3;
border-left: 4px solid #1abc9c;
padding: 15px;
margin: 20px 0;
}
function calculateTargetHeartRate() {
// 1. Get input values
var ageInput = document.getElementById('hr-age').value;
var rhrInput = document.getElementById('hr-rhr').value;
// 2. Validate Age
if (ageInput === "" || isNaN(ageInput)) {
alert("Please enter a valid age.");
return;
}
var age = parseFloat(ageInput);
if (age 110) {
alert("Please enter a realistic age between 10 and 110.");
return;
}
// 3. Calculate Maximum Heart Rate (MHR)
// Formula: 220 – Age
var mhr = 220 – age;
// Variables for zones
var fatBurnLow, fatBurnHigh, cardioLow, cardioHigh;
var methodText = "";
// 4. Check if Resting Heart Rate (RHR) is provided for Karvonen Formula
if (rhrInput !== "" && !isNaN(rhrInput)) {
var rhr = parseFloat(rhrInput);
if (rhr = mhr) {
alert("Please check your Resting Heart Rate. It seems invalid relative to your age.");
return;
}
// Karvonen Formula: Target = ((MHR – RHR) * %Intensity) + RHR
var hrr = mhr – rhr; // Heart Rate Reserve
// Fat Burn (60% – 70%)
fatBurnLow = Math.round((hrr * 0.60) + rhr);
fatBurnHigh = Math.round((hrr * 0.70) + rhr);
// Cardio (70% – 80%)
cardioLow = Math.round((hrr * 0.70) + rhr);
cardioHigh = Math.round((hrr * 0.80) + rhr);
methodText = "Calculation Method: Karvonen Formula (More Accurate)";
} else {
// Standard Formula: Target = MHR * %Intensity
// Fat Burn (60% – 70%)
fatBurnLow = Math.round(mhr * 0.60);
fatBurnHigh = Math.round(mhr * 0.70);
// Cardio (70% – 80%)
cardioLow = Math.round(mhr * 0.70);
cardioHigh = Math.round(mhr * 0.80);
methodText = "Calculation Method: Standard MHR (220-Age)";
}
// 5. Update the UI
document.getElementById('res-mhr').innerHTML = mhr + " bpm";
document.getElementById('res-fatburn').innerHTML = fatBurnLow + " – " + fatBurnHigh + " bpm";
document.getElementById('res-cardio').innerHTML = cardioLow + " – " + cardioHigh + " bpm";
document.getElementById('method-used').innerHTML = methodText;
// Show results container
document.getElementById('hr-results-display').style.display = 'block';
}
How to Calculate My Target Heart Rate for Weight Loss
When it comes to weight loss, not all exercise is created equal. While moving your body is always beneficial, understanding how to calculate your target heart rate for weight loss allows you to work smarter, not just harder. By training in specific heart rate zones, you can optimize your body's ability to burn fat as a primary fuel source.
Why does Heart Rate matter? Your heart rate is a direct indicator of exercise intensity. Different intensities trigger different metabolic systems in your body. Training too lightly might not burn enough calories, while training too hard might shift your body into burning glycogen (sugar) instead of fat reserves.
Understanding the "Fat Burning Zone"
You may have seen charts on treadmills referencing the "Fat Burning Zone." But what does that actually mean? Physiologically, this zone corresponds to a moderate intensity level where your body relies primarily on fat oxidation for energy.
- Fat Burning Zone (60% – 70% of Max HR): In this range, roughly 85% of the calories you burn come from fat. It is a comfortable pace where you can hold a conversation (Zone 2). It's ideal for long-duration workouts.
- Aerobic/Cardio Zone (70% – 80% of Max HR): As intensity increases, you burn more total calories per minute, but the percentage of calories from fat drops to about 50%. This zone improves cardiovascular health and lung capacity.
The Math: How the Calculation Works
There are two primary methods used to calculate these zones. Our calculator above uses the standard method by default but upgrades to the Karvonen formula if you input your resting heart rate.
1. The Standard Method (MHR)
This is the simplest way to estimate your zones. First, calculate your Maximum Heart Rate (MHR):
MHR = 220 - Age
Then, multiply by the intensity percentage. For example, for a 40-year-old wanting to hit 60% intensity:
(220 - 40) x 0.60 = 108 BPM
2. The Karvonen Formula (More Accurate)
This method is superior because it accounts for your fitness level by including your Resting Heart Rate (RHR). A lower RHR generally indicates better fitness.
Target HR = ((Max HR - Resting HR) x %Intensity) + Resting HR
If you have a low resting heart rate, the Karvonen formula will give you a slightly higher, more appropriate target range than the standard method.
How to Measure Your Heart Rate
To use the results from the calculator effectively, you need to monitor your pulse during exercise. You can do this by:
- Wearable Tech: Smartwatches and chest straps provide real-time data and are the most convenient option.
- Manual Check: Pause briefly, find your pulse at your wrist (radial) or neck (carotid), count the beats for 10 seconds, and multiply by 6.
Strategic Tips for Weight Loss
While the "Fat Burning Zone" burns a higher percentage of fat, higher intensity workouts burn more calories overall. A balanced plan often yields the best results:
- LISS (Low-Intensity Steady State): Aim for 45-60 minutes in the Fat Burning Zone (60-70%) 2-3 times a week. This is less stressful on the body and great for beginners.
- HIIT (High-Intensity Interval Training): Incorporate short bursts of high intensity (80-90%) followed by rest. This creates an "afterburn" effect (EPOC) where your body continues to burn calories after the workout.