Bruce Protocol — Treadmill Stress Test METs & VO2max
7 stages (4.6–19.1 METs), 3 min each. Foster and gender-specific formulas estimate VO2max. Stage 3 = average, Stage 5+ = athletic. Used in 90% of cardiac stress tests. Dr. Robert Bruce 1963.
Why This Stat Matters
Why: Bruce Protocol is the gold standard for treadmill stress testing. 90% of cardiac stress tests use it. VO2max estimation from time without lab.
How: Enter time completed and stage reached. Foster and gender-specific formulas estimate VO2max. Get fitness classification by age and gender.
- ●Stage 3 = average adult; Stage 5+ = athletic
- ●7 stages, 4.6–19.1 METs
- ●90% of cardiac stress tests use Bruce Protocol
7 Stages • 4.6–19.1 METs • VO2max Estimate
Foster and gender-specific formulas. Stage 3 = average, Stage 5+ = athletic.
Preset Scenarios
METs by Stage
For educational and informational purposes only. Verify with a qualified professional.
🏅 Sports Records
Bruce Protocol developed 1963 by Dr. Robert Bruce
Used in ~90% of treadmill stress tests worldwide
Stage 3 = average; Stage 5+ = athletic capacity
The Bruce Protocol uses 7 stages (4.6–19.1 METs) with 3-minute increments. Your VO2max is estimated from total time using Foster and gender-specific formulas. Stage 3 represents average adult fitness; Stage 5+ indicates athletic capacity. The protocol is used in 90% of cardiac stress tests worldwide and was developed by Dr. Robert Bruce in 1963.
📋 Key Takeaways
- • 7 stages from 4.6 to 19.1 METs — each stage 3 minutes
- • Foster formula and gender-specific (2.94×time + constant) estimate VO2max
- • Stage 3 = average adult; Stage 5+ = athletic
- • 90% of cardiac stress tests use the Bruce Protocol
💡 Did You Know?
📖 How It Works
Foster VO2max Formula
VO2max = 14.76 − (1.379×time) + (0.451×time²) − (0.012×time³). Time in minutes. Polynomial fit to treadmill time.
Gender-Specific Formula
Men: VO2max = 2.94×time + 3.74. Women: VO2max = 2.94×time + 0.59. Accounts for physiological differences.
METs by Stage
Stage 1: 4.6 METs. Stage 4: 12.9 METs. Stage 7: 19.1 METs. 1 MET = resting metabolic rate (~3.5 ml O2/kg/min).
🎯 Expert Tips
Warm up adequately
Light walking 5–10 min before the test. Cold starts can underestimate true capacity.
Use both formulas
Foster and gender-specific formulas can differ; averaging gives a robust estimate.
Stage matters for METs
METs are assigned by stage reached, not interpolated. Record exact stage and partial time.
Age-adjusted norms
Fitness classification uses age and gender norms. Compare to your cohort, not absolute values.
⚖️ Comparison Table
| Stage | METs | Fitness Level | Typical Use |
|---|---|---|---|
| 1–2 | 4.6–7.0 | Below average | ❌ |
| 3 | 10.1 | Average | ⚠️ |
| 4 | 12.9 | Good | ✅ |
| 5+ | 15.0–19.1 | Athletic/Elite | ✅ |
📊 Infographic Stats
📚 Official Sources
⚠️ Disclaimer: This calculator provides estimates for educational purposes. VO2max from treadmill time is an approximation; lab testing is the gold standard. Do not use for medical diagnosis. Consult a physician before starting any exercise program. Not a substitute for professional medical or fitness assessment.