Skip to main content

Physical Exercise & Our Cardiorespiratory Fitness

Written by Rhys. J | Accredited Exercise Physiologist, PsychPhys™

If we all knew one fact about exercise, it would be that engaging in it on a regular basis helps to make us more fit and healthy, but past this we might not understand ‘in what ways?’. This review piece will be designed to break down some of the research we have available to use to provide a greater understanding of some of the changes and adaptations that are occurring within our body when we are engaging in ongoing exercise.

Cardiovascular Fitness

In essence, cardiovascular fitness can be defined as the capacity of our cardiovascular system to supply oxygenated blood to our working muscles while also included the ability of our muscles to utilize the oxygen provided for movement. Currently, we have garnered an understanding through research that our cardiovascular fitness is inversely correlated with a variety of health conditions, including but not limited to: Hypertension (1, 2, 3); metabolic syndrome (1); cardiovascular disease(s) (2); stroke (1, 3); and all-cause mortality (3), among others.

But how can exercise change this?

Upon engaging in physical exercise, our body begins to change on a physiological level:

  • Our blood profile tends to improve
  • Reduced total cholesterol levels – Increased HDL cholesterol and apoliprotein A1 and reduced LDL cholesterol
  • Reduced triglycerides levels
  • Improved blood glucose management – Lower levels of fasting insulin and hbA1c levels
  • We can see adaptive remodelling of the heart and positive effects on our blood vessels 4
  • ‘Stronger’ heart through thickening of the ventricular chamber wall
  • Increasing cardiac output (amount of oxygenated blood our heart pumps per minute)
  • Reduction in blood pressure at rest and exercise
  • Reduction in atherosclerotic plaque formation/plaque instability within our blood vessels.

What can we do to improve our cardiorespiratory fitness?

There are many things we can do to improve our cardiorespiratory fitness, but we can use the physical activity guidelines to help gain an understanding of what is usually recommended.

Children and Young People (5 to 17 years)

60 minutes of moderate to vigorous physical activity per day (can be accumulated by several shorter bouts) Incorporating vigorous activities and muscle and bone strengthening activities at least 3 days per week.

Adults (18 to 64 years)

150 minutes of moderate intensity physical activity and/or 75 minutes of vigorous intensity physical activity (additional benefits if you were to double the duration) Muscle strengthening activities on at least 2 days per week If we are just starting out; however, these numbers could look quite daunting. Don’t fret!

  • Using smaller bouts (e.g., multiple 10-minute bouts) can be just as beneficial, and potentially even more sustainable, when compared with one bigger bout.
  • Choose an activity that you readily enjoy participating in to assist with motivation towards performing it in a consistent matter


  1. Myers, J., Kokkinos, P., & Nyelin, E. (2019). Physical activity, Cardiorespiratory fitness, and the Metabolic syndrome. Nutrients, 11(7), 1652
  2. Lin, X., Zhang, X., Guo, J., Roberts, C. K., McKenzie, S., Wu, W-C., Liu, S., & Song, Y. (2015). Effects of exercise training on cardiorespiratory fitness and biomarkers of cardiometablic health: A systematic review and meta-analysis of randomized controlled trials. Journal of the American Heart Association, 4(7), e.002014, doi: 10.1161/JAHA.115.002014
  3. McKinney, J., Lithwick, D. J., Morrison, B. N., Nazzari, H., Isserow, S., Heilbron, B., & Krahn, A. D. (2016). The health benefits of physical activity and cardiorespiratory fitness. British Columbia Medical Journal, 58, 131-137
  4. Nystoriak, M. A., & Bhatnagar, A. (2018). Cardiovascular effects and benefits of exercise. Frontiers in Cardiovascular Medicine, 5, 135