Calculate Target Hr

Target Heart Rate Calculator

(Measure first thing in the morning before activity)

function calculateTargetHR() { var age = parseFloat(document.getElementById("userAge").value); var restingHR = parseFloat(document.getElementById("restingHR").value); var targetZoneLower = parseFloat(document.getElementById("targetZoneLower").value); var targetZoneUpper = parseFloat(document.getElementById("targetZoneUpper").value); var resultDiv = document.getElementById("targetHRResult"); if (isNaN(age) || age <= 0 || isNaN(restingHR) || restingHR <= 0 || isNaN(targetZoneLower) || targetZoneLower <= 0 || isNaN(targetZoneUpper) || targetZoneUpper = targetZoneUpper) { resultDiv.innerHTML = "The lower target zone percentage must be less than the upper target zone percentage."; resultDiv.style.backgroundColor = "#f8d7da"; resultDiv.style.borderColor = "#f5c6cb"; resultDiv.style.color = "#721c24"; return; } if (targetZoneLower > 100 || targetZoneUpper > 100) { resultDiv.innerHTML = "Target zone percentages should not exceed 100%."; resultDiv.style.backgroundColor = "#f8d7da"; resultDiv.style.borderColor = "#f5c6cb"; resultDiv.style.color = "#721c24"; return; } // Calculate Maximum Heart Rate (MHR) using the common formula var maxHR = 220 – age; // Calculate Heart Rate Reserve (HRR) var hrr = maxHR – restingHR; // Calculate Target Heart Rate Zone using Karvonen Formula var lowerTargetHR = (hrr * (targetZoneLower / 100)) + restingHR; var upperTargetHR = (hrr * (targetZoneUpper / 100)) + restingHR; resultDiv.innerHTML = "Your Estimated Maximum Heart Rate (MHR): " + maxHR.toFixed(0) + " bpm" + "Your Target Heart Rate Zone: " + lowerTargetHR.toFixed(0) + " – " + upperTargetHR.toFixed(0) + " bpm"; resultDiv.style.backgroundColor = "#e9f7ee"; resultDiv.style.borderColor = "#d4edda"; resultDiv.style.color = "#155724"; }

Understanding Your Target Heart Rate

Your Target Heart Rate (THR) is a range of heartbeats per minute that you should aim for during exercise to achieve optimal cardiovascular benefits. Exercising within your THR zone helps you improve your fitness, burn calories, and strengthen your heart and lungs effectively.

Why is it Important?

• Effective Workouts: Ensures you're working hard enough to see results without overtraining.
• Fat Burning: Different zones can optimize fat burning versus improving endurance.
• Safety: Helps prevent overexertion, especially for individuals new to exercise or with certain health conditions.
• Progress Tracking: Provides a measurable goal for your fitness journey.

How is it Calculated? (The Karvonen Formula)

While a simple formula (220 – Age) can estimate your Maximum Heart Rate (MHR), a more precise method for determining your Target Heart Rate Zone is the Karvonen Formula. This formula takes into account your Resting Heart Rate (RHR), which provides a more personalized approach to your fitness level.

1. Estimate Maximum Heart Rate (MHR): The most common formula is 220 - Your Age. For example, if you are 30 years old, your MHR is approximately 220 – 30 = 190 bpm.
2. Determine Heart Rate Reserve (HRR): This is the difference between your MHR and your Resting Heart Rate (RHR). HRR = MHR - RHR. Your RHR is best measured first thing in the morning before any activity. For instance, if your RHR is 60 bpm, your HRR would be 190 – 60 = 130 bpm.
3. Calculate Target Heart Rate Zone: This is done by multiplying your HRR by your desired exercise intensity percentage (e.g., 60% for moderate, 80% for vigorous) and then adding your RHR back.
   • Lower THR = (HRR × Lower Intensity %) + RHR
   • Upper THR = (HRR × Upper Intensity %) + RHR

Example Calculation:

Let's say you are 30 years old, have a Resting Heart Rate of 60 bpm, and want to train in the 60% to 80% intensity zone:

1. MHR: 220 – 30 = 190 bpm
2. HRR: 190 – 60 = 130 bpm
3. Lower Target HR (60%): (130 × 0.60) + 60 = 78 + 60 = 138 bpm
4. Upper Target HR (80%): (130 × 0.80) + 60 = 104 + 60 = 164 bpm

Your target heart rate zone for this workout would be 138 to 164 bpm.

Different Intensity Zones:

• Very Light (50-60% MHR): Warm-up, cool-down, recovery.
• Light (60-70% MHR): Improves basic endurance and fat burning.
• Moderate (70-80% MHR): Improves aerobic fitness, cardiovascular health.
• Hard (80-90% MHR): Improves anaerobic capacity and speed endurance.
• Maximum (90-100% MHR): Short bursts, only for highly fit individuals.

Always consult with a healthcare professional or fitness expert before starting any new exercise program, especially if you have underlying health conditions.