Unlike chronological age, which measures exactly how long you have been alive, biological age (also known as physiological or phenotypic age) refers to how old your body seems. It is a reflection of how your cells and tissues have aged based on lifestyle, genetics, and environmental factors.
Key Factors Influencing Your Body Age
Cardiovascular Health: A lower resting heart rate often indicates a more efficient heart and better aerobic fitness.
Dietary Habits: High intake of antioxidants and low consumption of processed sugars can "slow down" the biological clock.
Physical Activity: Regular exercise helps maintain telomere length, which is a key marker of cellular longevity.
Stress Management: High cortisol levels from chronic stress are linked to premature aging and age-related diseases.
Example Calculations
Example 1: The Healthy Optimizer
A 45-year-old male who exercises 5 days a week, sleeps 8 hours, has a resting HR of 55, and eats a plant-rich diet may have a biological age of 38.
Example 2: The Sedentary Lifestyle
A 45-year-old male who does not exercise, smokes, sleeps 5 hours, and has high stress levels may have a biological age of 54.
How to Lower Your Biological Age
The good news is that biological age is plastic—it can change. By improving your sleep quality, increasing your VO2 max through zone 2 training, and reducing systemic inflammation through diet, you can effectively "reverse" your body's internal clock over time.
function calculateBiologicalAge() {
var chronoAge = parseFloat(document.getElementById('chronoAge').value);
var rhr = parseFloat(document.getElementById('restingHR').value);
var sleep = parseFloat(document.getElementById('sleepHours').value);
var exercise = parseFloat(document.getElementById('exercise').value);
var diet = parseFloat(document.getElementById('dietScore').value);
var stress = parseFloat(document.getElementById('stress').value);
var smoking = document.getElementById('smoking').value;
var sex = document.getElementById('sex').value;
if (isNaN(chronoAge) || isNaN(rhr) || isNaN(sleep) || isNaN(diet) || isNaN(stress)) {
alert("Please fill in all fields with valid numbers.");
return;
}
var ageAdjustment = 0;
// Heart Rate Factor (Normal range 60-70)
if (rhr 80) ageAdjustment += 3;
else if (rhr > 100) ageAdjustment += 5;
// Exercise Factor
if (exercise == 0) ageAdjustment += 4;
else if (exercise == 1) ageAdjustment += 1;
else if (exercise == 3) ageAdjustment -= 2;
else if (exercise == 5) ageAdjustment -= 4;
// Sleep Factor (Optimal 7-8)
if (sleep = 7 && sleep 9) ageAdjustment += 1;
// Diet Factor (1-10)
if (diet >= 8) ageAdjustment -= 3;
else if (diet = 8) ageAdjustment += 3;
else if (stress <= 3) ageAdjustment -= 1;
// Smoking Factor
if (smoking === "current") ageAdjustment += 7;
else if (smoking === "former") ageAdjustment += 2;
// Sex adjustment (Statistically females often have lower bio-age markers)
if (sex === "female") ageAdjustment -= 1;
var finalBioAge = chronoAge + ageAdjustment;
// Ensure we don't return an impossible age
if (finalBioAge = 18) finalBioAge = 18;
var resultDiv = document.getElementById('bioResult');
var valueDiv = document.getElementById('bioValue');
var descDiv = document.getElementById('bioComparison');
resultDiv.style.display = "block";
valueDiv.innerHTML = Math.round(finalBioAge * 10) / 10 + " Years";
var diff = finalBioAge – chronoAge;
if (diff 2) {
descDiv.innerHTML = "Your biological markers suggest your body is aging faster than average. Focus on improving sleep and reducing stress to lower this score.";
valueDiv.style.color = "#e67e22";
} else {
descDiv.innerHTML = "Your biological age is right on track with your chronological age. Small lifestyle tweaks could help you optimize further.";
valueDiv.style.color = "#2980b9";
}
resultDiv.scrollIntoView({ behavior: 'smooth' });
}