You’re sitting with a patient who gets short of breath walking to the bathroom, but you’re not sure how to quantify their tolerance. That’s where Metabolic Equivalents (METs) come in—a simple, powerful way to talk about energy demand across almost every patient scenario.
What are Metabolic Equivalents (METs)?
A metabolic equivalent (MET) is a unit of oxygen consumption used to estimate the energy cost of physical activity. One MET equals the resting oxygen consumption of an average adult: 3.5 mL of oxygen per kilogram of body weight per minute. In practice, METs tell you how many times above resting a given activity costs the body. Sitting quietly is 1 MET; brisk walking at 3–4 mph is roughly 4 METs; running is 8+ METs.
Why METs Matter in Physical Therapy Practice
METs give you a shared language for exercise prescription, activity tolerance, and safe progression. They are especially critical in cardiac rehabilitation and acute care, where exceeding a patient’s safe metabolic threshold can trigger ischemia, arrhythmia, or excessive fatigue. In your Plan of Care (POC), METs help you set functional goals—like “patient will tolerate 3 METs for 10 minutes independently”—and justify the need for therapy to payers and physicians.
What You’ll See in the Clinic
You’ll use METs during an eval to match activity demands to a patient’s capacity. For example, self-care tasks are often 2–3 METs, while household chores can be 3–5 METs. A patient post-MI may be restricted to ≤4 METs before further testing.
“Day 2 post-CABG: Patient ambulated 200 feet at 2.5 METs with HR 98, no chest pain or dyspnea. Continue progressive walking with vitals monitoring; advance to stair training when tolerance reaches 4 METs.”
Common Pitfall & Pro Tip
⚠️ Pitfall: Treating MET values as absolute numbers. A 70-year-old deconditioned patient may hit 4 METs on a treadmill test while another patient with COPD cannot reach 2 METs without desaturation. Use METs as a framework, not a prescription set in stone.
💡 Pro Tip: Keep a quick MET reference in your clinic. When planning interventions, ask yourself: “Is this activity within 1–2 METs of the patient’s current capacity?” Then progress by adding speed, incline, or upper extremity involvement to increase demand.
Memory Aid for METs
Think “METS = My Energy Tracking System.” Each activity has a number: 1 is sitting, 2 is standing, 3 is walking, 4 is stairs, 5 is heavy chores, 6+ is vigorous exercise. The higher the number, the more oxygen your heart and lungs must deliver.
NPTE Connection
Expect NPTE questions that ask you to identify the MET level of a given activity, recognize safe activity progression after a cardiac event, or interpret exercise test results in cardiac rehab scenarios.
Related Physical Therapy Concepts
METs connect directly to Borg Rating of Perceived Exertion (RPE) and heart rate monitoring—both tools help you regulate intensity during exercise. You’ll also see METs paired with 6-Minute Walk Test results to estimate functional capacity and with cardiac rehabilitation phases to guide safe, progressive activity.
Quick Reference
✓ Key values: 1 MET = 3.5 mL O2/kg/min; <3 METs = limited capacity; 5+ METs = good for functional independence ✓ Priority level: High for cardiac, pulmonary, and deconditioned patients ✓ PT Interventions/Considerations: • Use MET levels to grade daily activities and exercise • Monitor vitals and symptoms during MET-based progression • Document MET tolerance in objective measures and POC goals • Adjust MET targets based on patient's age, fitness, and comorbidities
Bottom line: METs are your metabolic roadmap—know the number, respect the patient, and progress with purpose.