Keeping Your Heart Healthy With Exercise

Cardiorespiratory fitness (CRF) isn’t just an important indicator for endurance athletes, it is also a biomarker for cardiovascular risk factors.  Individuals with low fitness levels are more likely to have a higher waist circumference, hypertension, dyslipidemia, and pre-diabetes.  It should be easy to see why a low fitness level is associated with a higher risk for heart disease. 

Low CRF doesn’t necessarily mean sedentary behavior either. In a cohort study performed at Jebsen Center for Exercise in Medicine in Trondheim, Norway, participants were assessed for cardiovascular risk factor, CRF, and amount of time they spent each day for sedentary time and physical activity.  It was noted that the CRF held the strongest association to cardiovascular risk, independent of whether or not individuals were getting enough minutes exercise each day to satisfy the physical activity guidelines. 

What does this mean? It means following the guidelines alone might not be enough for everyone.  In essence, an unfit person is still likely to accumulate cardiovascular risk factors even though they meet the guidelines.  The American Heart Association recommends 30 minutes of moderate intensity activity per day or 150 minutes per week.  While this is an excellent starting point, it is somewhat subjective as the intensity is generally measured by a rating of perceived exertion (RPE). Oxygen consumption (VO2) gives us a much more objective number to use because the higher the work load or intensity, the more oxygen is needed.  VO2 is most commonly used in a relative format of milliliters of oxygen per kilogram of body weight per minute (ml/kg/min) because we can then compare fitness states for individuals of differing body sizes.

For this same reason VO2 max is just as if not more important from a health standpoint as it is from a performance standpoint.  VO2 max is the best measurement of cardiovascular fitness because it tells us how much oxygen is getting transported and used by the tissues.  The same study noted that subjects in the upper 40% of fitness category had a VO2 max of 34.4 ml/kg/min or higher for men, and 27ml/kg/min for women. For every 1 metabolic-equivalent (3.5 mL/kg/min) decrease in VO2, there was a 67% increased chance of cardiovascular risk for men and a 57% increase for women.

This is a perfect example of why exercise is medicine.  By increasing your fitness level (VO2 max), you can reduce your risk of heart disease, lower blood pressure, improve lipid profiles, and truly optimize your health.  VO2 max testing is an integral part of what we do here at SSMI.  If you have not had your VO2 max testing or if it has been a while from, schedule an appointment find out your current fitness category and heart rate training zones.  We can also provide you with additional services like an exercise consult or personal training to provide individualized programming to help you meet your exercise and health goals.  Don’t wait to invest in yourself, call us today at (480)664-4615.


Alex Edwards

Exercise Physiologist



Sandbakk S, Nauman J, Zisko N, et al. sedentary time, cardiorespiratory fitness and cardiovascular risk  factor clustering in older adults- the Generation 100 study. Mayo clinic Proc; DOI10.1016/jmayocp.2016.07.020.

Toxic Effects of Sedentariness on CV Risk Factors Blunted by Cardiorespiratory FitnessL Cohort Study. Medscape. Oct 28, 2016.