Peak exercise heart rate is the highest number of beats per minute (BPM) your heart can safely reach during maximum physical exertion. Tracking this metric is vital for athletes, fitness enthusiasts, and those undergoing cardiovascular rehabilitation to ensure they are training effectively without overstressing the heart muscle.
The Science Behind the Formulas
While the "220 minus age" formula is the most common, it is often criticized for its lack of precision across different age groups and fitness levels. This calculator provides three distinct scientific models:
Fox Formula (220 – Age): The standard baseline used globally since the 1970s.
Tanaka Formula (208 – 0.7 x Age): Developed in 2001, this formula is widely considered more accurate for adults over 40.
Gellish Formula (206.9 – 0.67 x Age): Often used for clinical stress testing and active populations.
What is the Peak Zone?
High-intensity training typically occurs between 85% and 100% of your maximum heart rate. This is known as the "Red Line" or "Peak Zone." Working in this zone improves your VO2 Max, increases anaerobic threshold, and boosts metabolic rate long after the workout ends (the EPOC effect).
Safety and Training Considerations
It is important to remember that these are estimates. Factors such as medication (especially beta-blockers), caffeine intake, stress, and hydration levels can significantly influence your actual heart rate. If you are just beginning an exercise program, experts recommend staying within the aerobic zone (50-70%) before attempting peak-intensity workouts.
Example Peak HR Calculation
For a 40-year-old using the Tanaka formula:
Max HR: 208 – (0.7 * 40) = 180 BPM
Peak Zone (90%): 180 * 0.90 = 162 BPM
function calculatePeakHR() {
var age = parseFloat(document.getElementById('hr-age').value);
var formula = document.getElementById('hr-formula').value;
var intensity = parseFloat(document.getElementById('hr-intensity').value);
var resting = parseFloat(document.getElementById('hr-resting').value) || 0;
if (isNaN(age) || age 120) {
alert("Please enter a valid age between 1 and 120.");
return;
}
var maxHR = 0;
// Apply Formulas
if (formula === "fox") {
maxHR = 220 – age;
} else if (formula === "tanaka") {
maxHR = 208 – (0.7 * age);
} else if (formula === "gellish") {
maxHR = 206.9 – (0.67 * age);
}
var peakValue = Math.round(maxHR * intensity);
var displayMax = Math.round(maxHR);
// Update UI
document.getElementById('hr-result-container').style.display = 'block';
document.getElementById('max-hr-val').innerHTML = displayMax + " BPM";
document.getElementById('peak-target-val').innerHTML = peakValue + " BPM";
// Generate Zones
var zones = [
{ name: "Light (50-60%)", low: 0.5, high: 0.6 },
{ name: "Moderate (60-70%)", low: 0.6, high: 0.7 },
{ name: "Aerobic (70-80%)", low: 0.7, high: 0.8 },
{ name: "Anaerobic (80-90%)", low: 0.8, high: 0.9 },
{ name: "Peak (90-100%)", low: 0.9, high: 1.0 }
];
var tableHtml = "";
for (var i = 0; i = zones[i].low && intensity 0.9 && zones[i].high == 1.0);
var rowClass = isCurrent ? "class='peak-zone'" : "";
tableHtml += "