Maximal Oxygen Consumption & Weighted Vest Walking Calculator
Compare the same walk with and without a weighted vest. Calories are estimates of total activity energy expenditure.
Estimated results
Your heart-rate intensity guide
Enter your age for estimated maximum heart rate, then add your measured resting heart rate for heart rate reserve. Your table updates automatically.
Estimate your VO₂max without an exercise test
For adults age 20–70, matching the original study. Uses your age, body weight, and resting heart rate entered above. Measure resting heart rate after at least five minutes of quiet rest.
Choose the category that best fits a typical week, including work, transport, home activities, and exercise.
Complete the inputs to estimate your VO₂max and update the table automatically.
This is a broad fitness estimate, not a measured VO₂max. Individual results can differ substantially. Use a known test result when available.
Optional: enter a known VO₂max or choose the questionnaire to calculate oxygen-uptake and MET ranges.
Enter your age to fill in the %HRmax column. Add resting heart rate to fill in the HR reserve column.
Polar Heart Rate Training Zones
See Polar’s five-zone system alongside the intensity table. These bpm ranges use Polar’s percentages with your Tanaka-estimated maximum heart rate.
Select a zone to highlight its overlap in the maximum-heart-rate column below, or show all five colors.
Different cutoffs: Polar Zone 2 is 60–70% of maximum HR, overlapping the table’s Light and Moderate categories. The colors compare %HRmax only; they do not assign Polar zones to HR reserve, VO₂, or RPE.
Cards show rounded bpm boundaries. At a shared percentage boundary, use the higher zone; Zone 5 includes 100%. The table keeps the reference’s original percentage endpoints. Colored labels show only the portion of each zone within that row; values below 50% have no Polar zone in this guide.
Source: Polar’s five heart-rate zones. Your device’s bpm ranges may differ if it uses another maximum HR or custom zones.
Scroll the table sideways if needed to see every column.
| Intensity | Heart rate reserve %HRR → your bpm |
Maximum heart rate %HRmax → your bpmColors = Polar zone overlap |
Oxygen uptake reserve %VO₂R → target VO₂ |
Maximum oxygen uptake %VO₂max → target VO₂ & METs |
Perceived exertion RPE scale: 6–20 |
|---|---|---|---|---|---|
| Very light | <30%— | <57%— | <30%— | <37%— | Very lightRPE <9 |
| Light | 30–39%— | 57–63%— | 30–39%— | 37–45%— | Very light to fairly lightRPE 9–11 |
| Moderate | 40–59%— | 64–76%— | 40–59%— | 46–63%— | Fairly light to somewhat hardRPE 12–13 |
| Vigorous | 60–89%— | 77–95%— | 60–89%— | 64–90%— | Somewhat hard to very hardRPE 14–17 |
| Near-maximal to maximal | ≥90%— | ≥96%— | ≥90%— | ≥91%— | Very hard or greaterRPE ≥18 |
HR reserve method: target bpm = resting HR + (intensity × HR reserve). %HRmax method: target bpm = intensity × estimated maximum HR.
VO₂ reserve method: target VO₂ = 3.5 + [intensity × (VO₂max − 3.5)]. %VO₂max method: target VO₂ = intensity × VO₂max. MET values below the %VO₂max targets equal that target VO₂ ÷ 3.5.
The percentages and effort ratings follow the supplied intensity reference. Bpm endpoints are rounded to the nearest whole beat; VO₂ and MET endpoints use one decimal. VO₂ values are in mL/kg/min, with resting VO₂ assumed to be 3.5 (1 MET). VO₂max uses your entered value or the questionnaire estimate; RPE is a reference scale. These approximate intensity categories do not establish a personal Zone 2 boundary.
Tanaka gives an age-based estimate, not a measured maximum. Individual heart-rate responses can differ.
How the estimate works and research sources
Level walking uses the published Looney et al. (2024) weighted-vest energy model: total power per kg = resting power + (standing power + walking power) × [1 + 1.38 × (vest mass ÷ body mass)1.21]. Walking power is 1.78 × speed0.58 + 0.27 × speed4, with speed in m/s and power in W/kg. This calculator assumes resting power of 1 W/kg and standing power of 0.21 W/kg. Power is converted to kcal with 1 kcal = 4184 J. For uphill treadmill walking, it adds the ACSM walking equation's grade component, 1.8 × speed (m/min) × fractional incline (mL/kg/min), converted at approximately 5 kcal/L oxygen. The uphill extension is an approximation; the vest study's directly tested conditions were level treadmill walking. Real energy expenditure varies by gait, terrain, fitness, and equipment.
Looney et al. (2024), weighted-vest walking model · ACSM walking equation discussed in peer-reviewed research
Estimated maximum heart rate uses Tanaka's equation, HRmax = 208 − (0.7 × age). Heart rate reserve is estimated HRmax minus measured resting heart rate. For a given fraction of HRR, target heart rate adds resting heart rate back after multiplying the reserve by that fraction. The two heart-rate methods are approximate and can give different ranges.
Tanaka, Monahan & Seals (2001), age-predicted maximum heart rate · ACSM explanation of the heart rate reserve method
The questionnaire uses the Jurca et al. (2005) non-exercise model: estimated METs = 18.07 + (2.77 × sex coefficient) − (0.10 × age) − (0.17 × BMI) − (0.03 × resting HR) + activity score. The sex coefficient is 0 for the female equation and 1 for the male equation; activity levels 1–5 use scores 0, 0.32, 1.06, 1.76, and 3.03. BMI uses body weight in kilograms divided by height in meters squared. Estimated VO₂max = estimated METs × 3.5. The calculator retains full precision for the table and rounds only displayed results.
The original study included adults age 20–70, the age range supported by this questionnaire. This population-based model has substantial individual uncertainty and does not replace exercise testing.
Jurca et al. (2005), non-exercise fitness estimation · PhenX protocol and estimate limitations