You’re monitoring your patient’s exercise tolerance and need to know if they’re working hard enough to build endurance, but not so hard they’re at risk for cardiac events. The Borg Scale (Rate of Perceived Exertion) bridges the gap between objective physiology and the patient’s subjective experience—making it one of the most practical tools in physical therapy.
What is the Borg Scale?
The Borg Scale is a subjective assessment tool that quantifies a patient’s perceived exertion during physical activity. Developed by Gunnar Borg, it comes in two common forms: the original Borg RPE Scale (6–20), which correlates with heart rate (multiply by 10), and the Borg CR10 Scale (0–10), which is often used for dyspnea or general effort. The patient is asked to rate “how hard” they feel they are working, from “no exertion at all” to “maximal exertion.”
Why the Borg Scale Matters in Physical Therapy Practice
This scale gives you a safe, practical way to prescribe and progress exercise intensity without relying solely on heart rate monitors. It’s particularly valuable in cardiac rehabilitation, acute care, and neurological rehab where blood pressure response, medications, or autonomic dysfunction may make heart rate an unreliable guide. When documented consistently, it helps you adjust the Plan of Care (POC), progress or regress exercise loads, and ensure the patient is working within the appropriate intensity zone for their goals—whether that’s improving aerobic capacity or building strength.
What You’ll See in the Clinic
You’ll typically use the Borg Scale during a graded exercise test, gait training, or therapeutic exercise sessions. The patient gives a number, and you interpret it in context. For example, during a submaximal exercise tolerance test, you might ask the patient to keep their RPE between 11–13 (“light to somewhat hard”) to ensure they’re working at a moderate intensity.
“Patient ambulated 200 feet with a rolling walker. Reported RPE of 13/20 on the Borg Scale. Heart rate 112 bpm. Continue gait training at this intensity, progressing distance as tolerated, and reassess RPE each session.”
Common Pitfall & Pro Tip
⚠️ Pitfall: Assuming the patient’s RPE is accurate without anchoring. Many patients will pick a number randomly or say “10” because they think that’s what you want to hear. Also, avoid using RPE alone in patients with cognitive impairment or language barriers.
💡 Pro Tip: Anchor the scale before exercise by explaining the endpoints: “0 is sitting in this chair, 10 is the hardest you could possibly work.” During exercise, combine RPE with objective signs like heart rate, respiratory rate, and ability to speak. If the patient says “13” but is gasping for air, always trust the clinical picture over the reported number.
Memory Aid for the Borg Scale
For the original 6–20 scale, remember “Borg plus zero equals heart rate.” If a patient rates their exertion at 15, their estimated heart rate is roughly 150 bpm. This works surprisingly well in healthy adults and is a quick safety check during early rehab.
NPTE Connection
Watch for Borg Scale questions in the context of exercise prescription, cardiac rehabilitation, and monitoring patient response to intervention. The exam may ask you to identify the correct RPE range for a target heart rate zone or to interpret a patient’s rating in a clinical scenario.
Related Physical Therapy Concepts
The Borg Scale works alongside Target Heart Rate Zones, the Talk Test, and MET Levels to guide exercise intensity. It also connects to Rating of Perceived Dyspnea (often using the CR10 scale) and Fatigue Severity Scales in conditions like multiple sclerosis or heart failure. All of these tools help you individualize the POC and keep exercise both safe and effective.
Quick Reference
✓ Key values: 6–20 scale (original); 0–10 scale (CR10) ✓ Target RPE: 11–13 for moderate intensity; 14–16 for vigorous; <11 for low intensity ✓ Priority level: Moderate—but critical for cardiac and deconditioned patients ✓ PT Interventions/Considerations: • Use to guide progressive exercise intensity in aerobic conditioning • Monitor perceived exertion during gait training, stair climbing, or functional tasks • Document RPE alongside HR, BP, and symptoms for safe progression • Re-anchor the scale each session to maintain reliability
Bottom line: The Borg Scale turns a simple question into a reliable clinical measurement—so you can push your patients just enough to make progress, without pushing them too far.