Conditioned Heart or Heart Condition

Top Line

Keeping heart and lung tissue healthy with regular cardio, cardiorespiratory fitness (CRF), greatly reduces your chances of all-cause mortality.


Why It Matters

While heart disease is the number one killer in the United States and heart attacks affecting more people every year than the population of Dallas, Texas, 72% of Americans do not consider themselves at risk of the disease and 58% of Americans put no effort into improving their heart health. (1)


Key Takeaways

  • CRF is one of the strongest independent predictors of mortality
  • The best way to maintain a healthy cardiorespiratory system is through physical exercise
  • Increasing the intensity of training will increase development of CRF capacity
  • Increasing the duration training will increase development of CRF endurance


Three Billion Pumps

There’s a lot that we know about our hearts.

They will beat around three billion times over our lifetime, without us having to think about it! Every day, our heart pumps blood through a system of blood vessels over 60,000 miles long, providing our cells with necessary oxygen and nutrients.2 Through modern science, we well understand the link between our vitality and a healthy, functioning cardiorespiratory system — a term referring to our body’s entire process for the absorption, circulation, and consumption of oxygen and we’ve known about the importance of our heart for at least five hundred years.10 The earliest known writings on the circulatory system appeared on papyrus uncovered in Egyptian tombs, dating back to the 16th century BCE, which described a physiological connection between the heart and the arteries.9 

What we don’t know, however, is this: why are 58% of Americans making no effort to improve their heart health?1


Cardio for Heart Health

Studies have shown time and time again that The best way to maintain a healthy cardiorespiratory system is through physical exercise. This should not come as a surprise — after all the heart itself is a muscle! 

CRF, or ‘cardio’ is best measured as maximal oxygen consumption, or VO2max. This is a measurement, usually taken during a ‘stress test,’ that tell us your body’s ability to deliver and use oxygen to produce energy for muscle contraction (see know your numbers – VO2max)

Testing your VO2max isn’t just advised for the most serious fitness buffs among us, either. CRF actually has been one of the most widely examined physiological variables, particularly as it relates to functional capacity and human performance. In fact, CRF is said to be one of the strongest independent predictors of mortality.6

There is now compelling evidence for this association…


Cardiorespiratory Fitness & Mortality

A European study by Ladenvall et al., (2016) followed a sample of middle-aged men for 45 years and concluded that low levels of cardiorespiratory fitness was associated with increased mortality rates, regardless of whether or not the 792 participants in the study had any of the traditional risk factors for mortality, such as smoking, high blood pressure and cholesterol. 

In a similar longitudinal study published in 2018 by the American College of Cardiology Foundation, the authors reported a distinct relationship between fitness and longevity. They concluded that the benefits of higher midlife cardiorespiratory fitness extend well into the later part of life. 

Still not convinced a conditioned heart is the way to go?

A qualitative study by Kodama et al., (2009) was designed to assess the results of 33 different health investigations and evaluate a sample size of 102,980 healthy men and women. At the end of this study researchers concluded that individuals with higher cardiorespiratory fitness levels were associated with lower all-cause mortality.  


Improving & Maintaining Cardiorespiratory Fitness

Even though there is a strong association between physical inactivity and poor health outcomes particularly around heart health, 60% of the population is still inadequately active or completely inactive.5 Barriers to exercise often include lack of time, lack of social support, disruptions in routine, lack of access to facilities, and just an overall aversion to vigorous exercise.4 Prioritizing exercise for many is easier said than done but choosing to ignore the overwhelming science of heart health and exercise is, in a nutshell, choosing to have a heart condition over a conditioned heart. Regularly performing aerobic exercise (see energy systems) is the recommended method of maintaining an adequate level CRF.

Guidelines include: (10)


  • 30 to 60 minutes of moderate intensity exercise per day (≥ 150 min/week)
  • 20 to 60 minutes of high intensity exercise per day (≥ 75 min/week)
  • A combination of the above to achieve a similar total volume


By manipulating the intensity or duration of the exercise you can place greater emphasis on development of capacity or endurance as it relates to CRF. (10)


  • Increasing the intensity of training will increase development of CRF CAPACITY 
  • Increasing the duration training will increase development of CRF ENDURANCE

Don’t have enough time in the day to exercise 20-60 minutes?

  • Break up your day - Incorporate physical activity breaks into sitting time at work and at home
  • Change the intensity - If you are willing to increase exercise intensely, high intensity interval training can be an extremely effective way to improve cardiorespiratory fitness
  • Change how you get from point A to point B - Active commuting will increase your volume of training
  • Schedule it – Adding a time workout to your calendar can be a simply but effective tool for motivation and accountability
  • Train with someone – no one said you had to do it alone. Combining socializing with physical activity can look like a lot of things, from team sports to running partners

For personalized exercise prescription a qualified exercise physiologist can assist you in optimizing CRF capacity and endurance. 

George Crouch, MSc




  1. American Heart Association, (2020).
  2. Cabin, H. S., & Henry, S. (1992). The heart and circulation. The Heart Book, 3-10.
  3. Clausen, J. S., Marott, J. L., Holtermann, A., Gyntelberg, F., & Jensen, M. T. (2018). Midlife cardiorespiratory fitness and the long-term risk of mortality: 46 years of follow-up. Journal of the American College of Cardiology72(9), 987-995.
  4. Dishman, R. K., & Sallis, J. F. (1994). Determinants and interventions for physical activity and exercise.
  5. Dunn, A. L., Marcus, B. H., Kampert, J. B., Garcia, M. E., Kohl III, H. W., & Blair, S. N. (1999). Comparison of lifestyle and structured interventions to increase physical activity and cardiorespiratory fitness: a randomized trial. JAMA281(4), 327-334.
  6. Harber, M. P., Kaminsky, L. A., Arena, R., Blair, S. N., Franklin, B. A., Myers, J., & Ross, R. (2017). Impact of cardiorespiratory fitness on all-cause and disease-specific mortality: advances since 2009. Progress in Cardiovascular Diseases60(1), 11-20.
  7. Kodama, S., Saito, K., Tanaka, S., Maki, M., Yachi, Y., Asumi, M., ... & Yamada, N. (2009). Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. Jama301(19), 2024-2035.
  8. Ladenvall, P., Persson, C. U., Mandalenakis, Z., Wilhelmsen, L., Grimby, G., Svärdsudd, K., & Hansson, P. O. (2016). Low aerobic capacity in middle-aged men associated with increased mortality rates during 45 years of follow-up. European Journal of Preventive Cardiology23(14), 1557-1564.
  9. Standring S. (2016). A brief history of topographical anatomy. Journal of Anatomy229(1), 32–62. 
  10. Swain, D. P., Brawner, C. A., & American College of Sports Medicine. (2014). ACSM's resource manual for guidelines for exercise testing and prescription. Wolters Kluwer Health/Lippincott Williams & Wilkins.