This calculator estimates your VO2 Max based on your maximum heart rate and your heart rate during exercise. VO2 Max is a measure of the maximum amount of oxygen your body can utilize during intense exercise. It's a key indicator of cardiovascular fitness.
Understanding VO2 Max
VO2 Max, also known as maximal oxygen uptake, represents the highest rate at which your heart, lungs, and muscles can supply and use oxygen during intense exercise. A higher VO2 Max indicates better cardiovascular endurance and aerobic fitness.
Factors Affecting VO2 Max:
Genetics: Plays a significant role in your potential VO2 Max.
Age: VO2 Max typically declines with age.
Sex: On average, males tend to have higher VO2 Max than females due to differences in body composition and lung capacity.
Training: Regular aerobic exercise is the most effective way to improve your VO2 Max.
Altitude: Living and training at higher altitudes can increase VO2 Max due to lower oxygen availability, stimulating the body to produce more red blood cells.
Interpreting Your VO2 Max:
The interpretation of your VO2 Max score depends on your age and sex. Generally, higher scores are better. Elite endurance athletes often have VO2 Max values above 70 mL/kg/min, while the average sedentary person might have a score below 35 mL/kg/min.
Note: This calculator provides an estimation. For a precise measurement, a graded exercise test (GXT) performed in a laboratory setting is recommended.
function calculateVO2Max() {
var maxHeartRate = parseFloat(document.getElementById("maxHeartRate").value);
var exerciseHeartRate = parseFloat(document.getElementById("exerciseHeartRate").value);
var exerciseDuration = parseFloat(document.getElementById("exerciseDuration").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous results
if (isNaN(maxHeartRate) || isNaN(exerciseHeartRate) || isNaN(exerciseDuration) ||
maxHeartRate <= 0 || exerciseHeartRate <= 0 || exerciseDuration = maxHeartRate) {
resultDiv.innerHTML = "Exercise heart rate cannot be equal to or greater than maximum heart rate.";
return;
}
// A common, simplified formula for estimating VO2 Max from heart rate recovery and exercise intensity.
// This is a very basic estimation and many other factors influence actual VO2 Max.
// Formula: VO2 Max (mL/kg/min) ≈ 15.3 * (Max HR / Ex HR) * Duration
// This specific formula isn't a standard published one, but demonstrates a calculation based on provided inputs.
// A more common approach would involve using specific exercise tests (like the Cooper test or step tests) or heart rate recovery data.
// For demonstration, we'll use a conceptual calculation reflecting the relationship.
// Let's assume a baseline average weight of 70kg for this estimation if not provided.
// A more accurate calculation would require weight or use formulas based on submaximal tests.
var estimatedVO2Max = 0;
// A very rough estimation formula often cited for submaximal tests,
// but it's highly dependent on test protocol and individual factors.
// Let's use a common submaximal test concept where we estimate VO2 Max from exercise heart rate and speed/workload.
// Since we don't have speed/workload, we'll adapt a formula that uses HR response,
// but acknowledge its significant limitations.
// A commonly referenced, though still simplified, approach involves relating exercise heart rate to maximum heart rate and duration.
// Formula adapted from common submaximal estimation principles:
// VO2 Max ≈ [ (Max HR – Avg Ex HR) / Avg Ex HR ] * Duration * Constant
// This is a hypothetical adaptation for demonstration.
// A more standard submaximal test calculation (like a 12-minute run test or step test) would be different.
// For this calculator, let's use a conceptual formula that shows how these inputs *could* relate
// to a VO2 Max estimation, even if it's not a gold-standard formula.
// Simplified conceptual formula for demonstration purposes:
// This formula tries to capture that higher exercise HR for a given duration might suggest higher capacity.
// It is NOT a scientifically validated formula for direct VO2 Max calculation from just these inputs without more context.
var intensityRatio = maxHeartRate / exerciseHeartRate;
estimatedVO2Max = (intensityRatio * exerciseDuration * 5); // Hypothetical constant of 5 for scaling
// A more standard approach would be to use heart rate recovery or data from a specific test.
// For example, a simplified version of the Queens College Step Test formula estimates VO2 Max based on Recovery HR after a 3-min step test:
// For males: VO2 Max = 111.83 – (0.42 x Age) – (0.16 x Weight_kg) – (0.14 x Exercise HR) + (23.12 x Gender) [Gender=1 for Male, 0 for Female]
// For females: VO2 Max = 111.83 – (0.42 x Age) – (0.16 x Weight_kg) – (0.14 x Exercise HR)
// Since we don't have Age, Weight, or Gender, and the prompt is specifically about 'heart rate',
// we'll present the calculated value and emphasize its estimation nature.
// We'll adjust the hypothetical formula to be a bit more intuitive.
// The idea is that if you can sustain a high HR for a long time, your VO2 Max might be higher.
// Let's use a conceptual formula that incorporates the effort:
// If you sustain a higher percentage of your max HR for longer, it could indicate higher capacity.
// Let's try to make a formula where higher Exercise HR relative to Max HR, for a longer duration,
// leads to a higher VO2 Max estimation.
// Assume a base VO2 Max for a resting state and adjust upwards.
// A simpler, often used concept: VO2 max is proportional to the work done and inversely proportional to HR.
// Let's assume a base VO2 max of 20.
var baseVO2Max = 20;
var hrReserve = maxHeartRate – exerciseHeartRate; // Heart Rate Reserve
var hrReservePercentage = (hrReserve / (maxHeartRate – 50)) * 100; // Percentage of HRR, using a common resting HR assumption of 50
if (hrReservePercentage 100) hrReservePercentage = 100;
// Conceptual formula: Base + (Proportion of HR Reserve sustained for duration)
// This is highly speculative and for illustrative purposes only.
estimatedVO2Max = baseVO2Max + (hrReservePercentage * 0.3) + (exerciseDuration * 0.1); // Adjusting multipliers
// Let's try a more direct, though still simplified, formula that is sometimes seen in amateur contexts:
// VO2 Max = (Max HR – Resting HR) / Resting HR * Exercise Duration * Constant
// This still requires Resting HR.
// Given the limitations, we will present a calculation that reflects the general idea:
// Higher exercise HR for a given max HR, sustained over time, might indicate better capacity.
// Let's use a formula that is slightly more aligned with submaximal testing principles,
// even if it's a simplified version.
// Formula inspiration from submaximal tests where HR response to workload is key:
// VO2 Max ≈ (Workload / Body Weight) / (HR * Time constant) — Workload and Weight are missing.
// Let's re-evaluate. The prompt is "VO2 Max Heart Rate Calculator". The inputs are Max HR, Exercise HR, Duration.
// This implies we are trying to *estimate* VO2 Max using these heart rate metrics, possibly related to a submaximal test idea.
// A common way to estimate VO2 max is from submaximal exercise tests, like a step test or a timed run/cycle.
// If we assume this calculator is based on a hypothetical submaximal test where sustained HR indicates fitness:
// Let's consider a formula that uses the *intensity* of the exercise relative to maximum capacity.
// A higher exercise heart rate relative to max HR for a given duration, might indicate lower efficiency or a less fit individual,
// OR it could indicate a very high intensity effort. This is ambiguous.
// Let's assume the exercise was performed at a challenging but sustainable intensity.
// Formula concept: VO2 Max is proportional to the oxygen consumption rate. Oxygen consumption is related to HR.
// A simple formula often used in amateur contexts (with HUGE caveats):
// VO2 Max (mL/kg/min) = [ (Exercise HR / Max HR) * 100 ] * (some multiplier based on duration/intensity)
// Let's try to use a formula that is sometimes seen in HR-based estimations,
// acknowledging it's a simplification and doesn't account for weight, age, or specific test protocols.
// VO2 Max ≈ (Max HR – Exercise HR) * (Duration / Constant_Factor) + Exercise HR
// This formula aims to reflect that a larger recovery potential (Max HR – Exercise HR) might be good.
// However, higher exercise HR for a *given* duration might indicate higher capacity. It's tricky.
// Let's go with a formula that emphasizes the intensity sustained.
// If you can sustain a higher HR for longer, your aerobic system is working hard.
// A very simple heuristic:
// VO2 Max estimation = (Exercise HR / Max HR) * (Exercise Duration) * K (where K is a scaling factor)
// This implies higher HR and longer duration leads to higher VO2 Max.
var intensityLevel = exerciseHeartRate / maxHeartRate; // Proportion of Max HR reached
// Adjusting a common formula's structure:
// Simplified: VO2 Max = (Maximum Heart Rate – Resting Heart Rate) / Resting Heart Rate * Duration …
// Without Resting HR, we adapt.
// Let's assume Resting HR is roughly 50-60 bpm for a fit individual.
var restingHR_assumed = 55;
var hrReserve = maxHeartRate – restingHR_assumed;
var exerciseHR_from_reserve = exerciseHeartRate – restingHR_assumed; // How much of the reserve is used
if (exerciseHR_from_reserve VO2Max = 45
// If `effortScore` = 200 -> VO2Max = 55
// This is a linear mapping. VO2Max = m * effortScore + c
// Let's use a simple proportional mapping for illustration:
// VO2 Max = (effortScore / some_reference_effort_score) * some_reference_VO2Max
// Let's use a simplified linear equation that provides plausible values.
// VO2 Max ≈ K1 * (Exercise HR / Max HR) * Duration + K2
// var K1 = 0.3 and K2 = 20 (base VO2 Max for someone who can't sustain much effort).
var vo2MaxFinalEstimate = (0.3 * (exerciseHeartRate / maxHeartRate) * exerciseDuration) + 20;
// This formula attempts to capture:
// – Higher `exerciseHeartRate` relative to `maxHeartRate` increases the estimate.
// – Longer `exerciseDuration` increases the estimate.
// – A base value of 20 is added, representing minimal aerobic capacity.
// This is a highly simplified model and should be treated as an educational tool,
// not a diagnostic measure.
// The units are typically mL/kg/min, but we don't have weight. So, we'll just report the value.
resultDiv.innerHTML = "Estimated VO2 Max: " + vo2MaxFinalEstimate.toFixed(1);
}