Cardiorespiratory fitness can be defined as the efficiency at which your cardiovascular, pulmonary, and musculoskeletal systems work together during exercise.
Why is CRF important?:
While we have all heard about the benefits of exercise, the general public does not often hear about the benefits associated with above average CRF. Low CRF has been shown to:
increase risk of mortality for all-cause and disease specific mortality (Harber et al., 2017)
be linked with specific forms of cardiovascular disease (Harber et al., 2017)
increased risk from cancer (Harber et al., 2017)
low CRF is an independent predictor for risk of mortality with cancer and CVD (Harber et al.
it was also found that it could be a predictor of long-term outcomes for individuals in early development of metabolic disease (Harber et al.)
So what are the potential positives associated with high CRF?
In Harber et al. (2017) it was found that maintaining a higher CRF at a young age creates the greatest chance at survival in old age. CRF fitness was found to be inversely associated with risk of cardiovascular disease. Men and women both saw benefits of higher CRF. A smaller decrease in CRF fitness with age was found to reduce risk of all-cause mortality when compared to individuals with larger decreases in CRF.
How is CRF measured?
The most recognized way of measuring cardiorespiratory fitness is maximal oxygen uptake during exercise of increasing intensity (VO2max). VO2max is the number of milliliters of oxygen you use per kilogram of body weight in one minute (ml/kg/min) (Jewel 2020). There are two main ways of measuring your VO2 max:
Maximal exercise tests are the gold standard for testing the VO2 max of athletes or highly fit individuals and are normally performed in a lab under open circuit spirometry. These tests include:
Submaximal exercise tests are an acceptable alternative for those that are less fit and are comfortable with estimations. These tests still feature incremental intervals of exercise, but feature many indicators to stop the test and estimate an individuals VO2max. Submax tests include:
These are the typical ranges for VO2max in men and women
(Firstbeat)
(Firstbeat)
Harber et al. (2017) recommends occasional VO2 max tests as a means to gauge your health and to reassess any workout programs intended to raise your CRF.
