Cardiorespiratory Fitness

The vital sign, Cardiorepiratory Fitness (CRF) level, is a glaring omission in healthcare. This vital sign should be assessed and documented and the fact that it is currently not needs to change. CRF is being ignored and overlooked to the detriment of patient health, quality of life and healthcare costs. CRF can easily be assessed by exercise professionals yet healthcare fails to assess and document CRF due to lack of reimbursement for such assessment. Primary care is tasked with the supervisory role in patient care and ignoring this vital sign is a serious mistake being made by many in primary care.

CRF represents an objective measurement of an individual’s ability to use oxygen to convert chemical energy (oxidation of food and stored energy – fat and glucose) into mechanical energy. It has been know since 1995 that poor CRF is an independent risk factor for the development of cardiovascular disease and all-cause mortality (1). Recently published in JAMA Network Open, 2018, it has been established that poor CRF increases a persons risk to all-cause mortality to the same level as having type II diabetes or smoking (2). While T2D or smoking would never be ignored in clinic the simple measurement of CRF is. Poor CRF creates a significant increase in hazard ratio for patients and is one that can be easily reversed and avoided. While the publication does advise health care professionals to encourage patients to achieve and maintain high levels of fitness it fails to point out that “steps” are not going to get individuals to high levels of fitness. Some “real” exercise will be needed along with the use of exercise professionals. The fact is, walking while better than being sedentary is not a “dose” of exercise that will increase fitness in anyone other than those with the lowest CRF, such as those that are bed ridden. Another glaring failure of this publication is not mentioning that measuring of CRF can be done easily, <15 minutes, by exercise professionals. CRF should be considered a vital sign of health but we continue to fail to monitor this powerful indicator of health. Here at Restore Medical Fitness all patients’ CRF is measured monthly, for those beginning programs, or in the case of those that have achieved higher levels of CRF, quarterly.

Restore Medical Fitness provides patients with assessments of fitness and personalized CRF prescription after CRF level and personal goals have been established. Patients of higher risk or that have been sedentary should be referred to an exercise professional for assessment and CRF prescription.

CRF is a major contributor to an individuals ability to perform work or physical tasks. When we say “work” you might think of loading trucks but you can also think of things like dancing, playing with children, raking leaves, grocery shopping, mowing the lawn, gardening and walking. Individuals with good CRF can do all those things easier than those with poor CRF. These abilities are, in part, activities that determine the quality of life a person has.

Just as important as living with the ability to do more activities comfortably, CRF is a modifiable indicator of long-term mortality. In other words, you are capable of influencing your level of CRF and having better CRF improves your odds of living a long and happy life.

On average, patients that have begun Restore Lifestyle Programs with CRF in the lowest third for their age and sex have increased their Metabolic Equivalent of Task maximum (MET max) from the lowest third to the middle third in just 90 days. This improvement cuts their hazard ratio for All-Cause mortality in half. These same people have, on average, achieved a 83% increase in MET max in 8 months and have maintained that level. This is an impressive improvement from baseline and greatly enhances their quality of life.


1 – Blair, et. al., JAMA, April 1995, Vol 273. No 14 – Changes in Physical Fitness and All-Cause Mortality

Conclusions: Men who maintained or improved adequate physical fitness were less likely to die from all causes and from cardiovascular disease during follow-up than persistently unfit men. Physicians should encourage unfit men to improve their fitness by starting a physical activity program.

 2 – Mandsager, et. al., JAMA Network Open, 2018;1(6):e183605 – Association of Cardiorespiratory Fitness with Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing

Conclusions and Relevance: Cardiorespiratory fitness is inversely associated with long-term mortality with no observed upper limit to the benefit. Extremely high aerobic fitness was associated with the greatest survival and was associated with benefit in older patients and those with hypertension. Cardiorespiratory fitness is a modifiable indicator of long-term mortality, and health care professionals should encourage patients to achieve and maintain high levels of fitness.