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Cardiorespiratory Fitness Training

What is cardiorespiratory fitness (CRF)?


  • The ability of our body to transport oxygen from the atmosphere to body cells to perform physical work.


  • It is strongly related to cardiovascular and all-cause mortality. People with good CRF have substantially lower all-cause mortality rate.


How do I measure exercise intensity?


  • You can measure exercise intensity by using heart rate reserve (HRR) and/or rate of perceived exertion (RPE)
  • Heart Rate Reserve (HRR)
    • Exercise intensity can be represented by Karvonen’s formula.
    • Maximum heart rate= 220 – age
    • Target heart rate= [(maximum HR − resting HR) × %Intensity] + resting HR
    • For example, target heart rate of one aged 40 exercising at 50% HRR (resting HR 70)
      • = (180 - 70) X 50% + 70 = 125 (target heart rate)
    • Rate of perceived exertion (RPE)
      • RPE is a 0-10 scale to measure the exercise intensity by your exertion.




RPE Scale

Activity Examples



Laying on a sofa

Very light


Doing laundry


2 to 3

Leisure walking


4 to 5

Brisk walking


6 to 7

Jogging, cycling, swimming

Very hard


The highest level of activity that you can continuing doing without stopping, such as running



A short burst of activity, such as a sprint, that you cannot keep doing for long



What types of exercise should I do to improve CRF?

  • Aerobic exercise with moderate to vigorous intensity
    • 40% to 90% of HRR OR RPE of 4 to 9 (for healthy individuals only)


Exercise precautions

  • Stop exercise if you experience
    • Chest pain
    • Shortness of breath
    • Dizziness
  • Consult a physician or physiotherapist before exercise if you have
    • Hypertension
    • Cardiovascular disease
    • Diabetes mellitus or other chronic diseases


The above information was produced by Physiotherapy Department, Canossa Hospital (Caritas).

Please call 28255392 for physiotherapy appointment



American College of Sports Medicine. (2016). ACSM’s Guidelines for Exercise Testing and Prescription (Tenth; D.Riebe, J. K.Ehrman, G.Liguori, &M.Magal, Eds.). Wolters Kluwer.

Kodama, S., Saito, K., Tanaka, S., Maki, M., Yachi, Y., Asumi, M., …Sone, H. (2009). Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: A meta-analysis. JAMA - Journal of the American Medical Association, 301(19), 2024–2035. https://doi.org/10.1001/jama.2009.681

Ross, R., Blair, S. N., Arena, R., Church, T. S., Després, J. P., Franklin, B. A., …Wisløff, U. (2016). Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement from the American Heart Association. Circulation, 134(24), e653–e699. https://doi.org/10.1161/CIR.0000000000000461

RPE: What does this scale tell you about exercise? (n.d.). Retrieved November18, 2020, from https://www.healthline.com/health/RPE#scale-comparison