Standard (Training regularly, no major issues)
Recovering from major illness/surgery/medication
Frequent injuries, illness, asthma, or inconsistent training
Training consistently for 2+ years with progress & no injury
Max Aerobic Heart Rate (MAF)
0bpm
This is your hard ceiling for Zone 2 training. Do not exceed this number during base runs.
Target Aerobic Training Zone
0 – 0bpm
Keep your heart rate within this range for 80% of your training volume.
function calculateTarenZone() {
// Get Inputs
var ageInput = document.getElementById('athleteAge');
var healthSelect = document.getElementById('healthStatus');
var resultBox = document.getElementById('tthrResult');
var ageError = document.getElementById('ageError');
var age = parseInt(ageInput.value);
var adjustment = parseInt(healthSelect.value);
// Reset Error
ageError.style.display = 'none';
resultBox.style.display = 'none';
// Validation
if (isNaN(age) || age 100) {
ageError.style.display = 'block';
return;
}
// Calculation Logic (180 Formula)
// 1. Start with 180
// 2. Subtract Age
// 3. Apply Adjustment
var baseFormula = 180;
var mafHeartRate = baseFormula – age + adjustment;
// Calculate the Zone Range (Usually MAF-10 to MAF)
var lowerZoneLimit = mafHeartRate – 10;
// Validating logical output (Heart rate shouldn't be absurdly low/high)
if (mafHeartRate < 100) mafHeartRate = 100; // Fail-safe floor
if (lowerZoneLimit < 90) lowerZoneLimit = 90;
// Update UI
document.getElementById('mafResult').innerText = mafHeartRate;
document.getElementById('zoneRange').innerText = lowerZoneLimit + " – " + mafHeartRate;
// Show Results
resultBox.style.display = 'block';
}
Understanding the Triathlon Taren Heart Rate Method
The Triathlon Taren (Mottiv) heart rate philosophy is heavily grounded in the Maffetone Method, also known as the 180 Formula. This approach prioritizes building a massive aerobic engine by training at a low heart rate, often referred to as "Zone 2" training. For age-group triathletes, this method helps prevent injury, reduces burnout, and ultimately leads to faster race times by increasing fat adaptation.
Why Use Low Heart Rate Training?
Many triathletes make the mistake of training in the "Grey Zone" (Zone 3)—too hard to recover from efficiently, but too easy to elicit top-end speed adaptations. The Triathlon Taren calculator helps you find your specific Maximum Aerobic Function (MAF) heart rate. By keeping your heart rate below this number for the majority of your training (approx. 80/20 rule), you improve your body's ability to use fat as fuel, sparing glycogen for the later stages of a race.
How the Calculation Works
The formula begins with the number 180. From there, you subtract your age. However, simply subtracting your age isn't enough; you must adjust for your physiological history. This calculator applies the standard adjustments used in this methodology:
-10 bpm: If you are recovering from a major illness (like heart disease) or surgery.
-5 bpm: If you are injured, regress in training often, get sick more than twice a year, or suffer from asthma.
0 bpm: If you have been training consistently (at least 4 times a week) for up to two years without any of the problems listed above.
+5 bpm: If you have been training for more than two years without problems and have made measurable progress in competition.
Using Your Results
Once you have your MAF Heart Rate calculated above, this number becomes your "ceiling." During your long runs and bike rides, your goal is to stay within the range provided (usually 10 beats below your MAF up to the MAF number). If your heart rate spikes above this number, you must slow down or walk until it drops back into the zone. Over time, you will find yourself running faster at the same low heart rate—a clear sign of increased aerobic efficiency.