Calculating Exercise Heart Rate

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Your Calculation Results

Max Heart Rate: 0 BPM

Target Heart Rate: 0 BPM

function calculateExerciseHR() { var age = parseFloat(document.getElementById('userAge').value); var resting = parseFloat(document.getElementById('restingHR').value); var intensity = parseFloat(document.getElementById('intensityLevel').value) / 100; var resultArea = document.getElementById('hrResultArea'); if (isNaN(age) || isNaN(resting) || age <= 0 || resting <= 0) { alert("Please enter valid numbers for age and resting heart rate."); return; } // Using the Karvonen Formula (more accurate than 220-age alone) // Target HR = ((Max HR – Resting HR) * %Intensity) + Resting HR var maxHR = 220 – age; var heartRateReserve = maxHR – resting; var targetHR = Math.round((heartRateReserve * intensity) + resting); document.getElementById('maxHRVal').innerHTML = maxHR; document.getElementById('targetHRVal').innerHTML = targetHR; var description = ""; if (intensity = 0.60 && intensity < 0.80) { description = "Zone: Aerobic / Cardio. Ideal for cardiovascular fitness and weight management."; } else { description = "Zone: Anaerobic / Performance. High intensity, builds speed and power."; } document.getElementById('hrZoneDesc').innerHTML = description; resultArea.style.display = 'block'; }

Understanding Your Exercise Heart Rate

Knowing your target heart rate (THR) is essential for anyone looking to maximize their workout efficiency. Whether you are training for a marathon, trying to lose weight, or improving cardiovascular health, your heart rate serves as a real-time dashboard for your effort levels.

The Karvonen Formula Explained

While many people use the simple "220 minus age" formula, fitness professionals often prefer the Karvonen Formula. This method takes your Resting Heart Rate (RHR) into account, providing a more personalized "Heart Rate Reserve." This is crucial because a marathon runner and a sedentary individual of the same age will have very different fitness capacities based on their resting pulse.

• Max Heart Rate: 220 – Your Age.
• Heart Rate Reserve (HRR): Max HR – Resting HR.
• Target Heart Rate: (HRR × Intensity%) + Resting HR.

Training Intensity Zones

Depending on your fitness goals, you should aim for different intensity percentages:

Intensity Zone	Benefit
50% – 60%	Warm-up, fat metabolism, and recovery.
60% – 70%	Weight control and building basic endurance.
70% – 85%	Aerobic fitness and cardiovascular strength.
85% – 95%	Anaerobic threshold training for athletes.

Practical Examples

Example 1: The Active Adult
A 40-year-old with a resting heart rate of 65 BPM wants to exercise at 70% intensity.
Max HR = 180. HRR = 115.
Target = (115 * 0.70) + 65 = 146 BPM.

Example 2: The High-Intensity Athlete
A 25-year-old athlete with a resting heart rate of 50 BPM wants to train at 90% intensity.
Max HR = 195. HRR = 145.
Target = (145 * 0.90) + 50 = 181 BPM.

How to Measure Your Resting Heart Rate

To get the most accurate result from this calculator, you need your true Resting Heart Rate. The best time to measure this is first thing in the morning, before you get out of bed or consume caffeine. Place two fingers on your wrist (radial pulse) or neck (carotid pulse) and count the beats for 60 seconds. Repeat this over three mornings and take the average for the most precise data.

Note: Always consult with a healthcare professional before starting a new vigorous exercise program, especially if you have underlying health conditions or are taking medications that affect heart rate (such as beta-blockers).