Metabolic Equivalent (METs) for Climbing a Flight of Stairs Without Stopping
Climbing a flight of stairs without stopping is equivalent to approximately 4 METs of exertion. 1
Understanding METs and Stair Climbing
Metabolic equivalents (METs) are a standardized way to measure energy expenditure during physical activities:
- 1 MET = resting oxygen consumption of a 70-kg, 40-year-old man (3.5 mL/kg/min) 1
- Climbing stairs is specifically referenced in guidelines as a benchmark activity for assessing functional capacity
According to the 2014 ACC/AHA guidelines, climbing a flight of stairs without stopping is categorized as an activity requiring >4 METs 1. This is a clinically significant threshold because:
- Activities requiring ≥4 METs are considered moderate functional capacity
- Perioperative cardiac and long-term risks are increased in patients unable to meet a 4-MET demand 1
Clinical Significance of the 4 MET Threshold
The ability to climb stairs without stopping has important prognostic value:
- In a study of 600 consecutive patients undergoing noncardiac surgery, those with poor exercise tolerance (inability to climb 2 flights of stairs) had significantly more perioperative myocardial ischemia and cardiovascular events 1
- The likelihood of serious complications was inversely related to the number of flights of stairs that could be climbed (p<0.01) 1
Practical Applications in Clinical Assessment
Stair climbing ability serves as a simple functional assessment tool:
Perioperative risk stratification: Patients who can climb ≥1 flight of stairs without stopping are considered to have ≥4 METs capacity 1
Cardiovascular risk assessment:
- Patients who can achieve ≥4 METs without symptoms generally have lower cardiovascular risk
- For cardiac patients, sexual activity is considered safe when a patient can achieve 3-5 METs without symptoms 1
Functional capacity classification:
- Poor: <4 METs
- Moderate: 4-6 METs
- Good: 7-10 METs
- Excellent: >10 METs 1
Important Considerations
The MET-REPAIR questionnaire validation study showed that self-reported stair climbing ability had the highest correlation with measured METs (AUROC 0.841) compared to other assessment methods 2
Patients who can climb more than 3 flights of stairs (approximately 54 steps) typically have better postoperative outcomes, even in those with severe chronic airflow obstruction 3
The prognostic value of METs is protocol-dependent, so the context of how the functional capacity is assessed matters 4
Most patients tend to overestimate their METs capacity when self-reporting 2
By using stair climbing as a functional assessment, clinicians can quickly estimate a patient's metabolic capacity and associated risk for various procedures and activities.