Understanding your maximum heart rate (MHR) is a crucial component of designing an effective and safe exercise program. Your MHR is the highest number of times your heart can beat per minute during maximal exertion. It's a foundational metric for determining your target heart rate zones during workouts. For example, if you're aiming for an intensity that's 70% of your MHR, knowing your MHR allows you to accurately calculate that target.
.calculator-container {
font-family: sans-serif;
max-width: 500px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ccc;
border-radius: 8px;
background-color: #f9f9f9;
}
.calculator-container h2 {
text-align: center;
margin-bottom: 20px;
color: #333;
}
.calculator-inputs {
margin-bottom: 20px;
}
.input-group {
margin-bottom: 15px;
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
.input-group input[type="number"] {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
}
button {
width: 100%;
padding: 12px 20px;
background-color: #4CAF50;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
transition: background-color 0.3s ease;
}
button:hover {
background-color: #45a049;
}
#result {
margin-top: 20px;
padding: 15px;
border: 1px solid #d4edda;
border-radius: 4px;
background-color: #d4edda;
color: #155724;
font-size: 18px;
text-align: center;
font-weight: bold;
}
function calculateMaxHeartRate() {
var ageInput = document.getElementById("age");
var resultDiv = document.getElementById("result");
var age = parseFloat(ageInput.value);
if (isNaN(age) || age <= 0) {
resultDiv.textContent = "Please enter a valid age.";
resultDiv.style.backgroundColor = "#f8d7da";
resultDiv.style.color = "#721c24";
return;
}
// The most common and simplest formula for estimating Max Heart Rate
// MHR = 220 – Age
var maxHeartRate = 220 – age;
resultDiv.textContent = "Your estimated Max Heart Rate is: " + maxHeartRate + " bpm";
resultDiv.style.backgroundColor = "#d4edda"; // Greenish background for success
resultDiv.style.color = "#155724"; // Dark green text
}