Cardiovascular vs. Strength training

by | Mar 15, 2026 | Uncategorized | 0 comments

In the world of exercise, there are two main ways of measuring fitness: cardiorespiratory fitness (CRF) or muscular strength. The gold-standard for CRF measurement is VO2max and is expressed as mL of oxygen consumed per minute per kg of body weight (ml/min*kg). Strength is measured differently in different groups, but the gold-standard is isometric (one-sided) leg strength and grip strength, measured in Newton-metres or maximum weight achieved for a single repetition. There remains confusion as to whether one form of fitness or the other is more important for individuals to measure and improve.

CRF is an extremely strong predictor of mortality in healthy and diseased individuals. One ‘metabolic equivalent of task’ (MET) is the average resting energy expenditure, equal to a VO2 of 3.5 mL/kg*min. Improving VO2max by 1 MET reduces cancer mortality by 7%, all-cause mortality by 10%, cardiovascular mortality by 13%, and sudden cardiovascular mortality by 50%1,2! The effects of longevity do not even begin to describe the difference in quality of life a higher CRF results in.

Having better CRF does not merely reduce risk of mortality. It increases the ability to perform physical tasks, from walking to hiking to running. It means taking stairs and climbing hills without trouble. It means sleeping better3 and reducing the number of medications one is on4, including for mental health, as cardiovascular exercise is stronger than medications in reducing depression and anxiety5.

The evidence shows that the average person needs only three days per week of dedicated cardiovascular training to substantially improve VO2max within 3-6 weeks6. The hard work of cardio exercise pays off in many ways, making it an essential measure.

Muscle strength is also another strong predictor of mortality. Increasing muscle strength above the bottom quartile reduces all-cause mortality by upwards of 50% and is even more protective in obese individuals7,8. Having stronger muscles reduces and prevents osteoporosis with age9, which reduces hospitalizations and death, and improves quality of life10.

Physical strength also opens the door to a different life. Independence is a primary result of strength, whether in opening jars, lifting items without injury, or correcting physical imbalances. Strength-focused resistance training is the most effective form of increasing muscular strength. Like cardiovascular training, strength training leads to improved mental wellness5. One needs to strength train fewer times than cardiovascular exercise to see strong benefits (1-3 times/week), but a longer timeline is needed to observe sustainable improvements.

Health can be improved either by muscle strengthening or improving CRF. Prioritizing one or the other is a personal choice. However, the main causes of death in Canada—cancer, heart disease, and respiratory diseases—are best mitigated by improving CRF1. Furthermore, cardiovascular exercise negates the effects of a sedentary lifestyle more than strength training, such as better insulin sensitivity11 and greater caloric expenditure for the same duration. Therefore, for a regular Canadian adult, measuring and improving CRF can be one of the most life changing choices they can make.

 

References

  1. Lang, J. J. et al. Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies. Br. J. Sports Med. 58, 556–566 (2024).
  2. Stamatakis, E., Hamer, M., O’Donovan, G., Batty, G. D. & Kivimaki, M. A non-exercise testing method for estimating cardiorespiratory fitness: associations with all-cause and cardiovascular mortality in a pooled analysis of eight population-based cohorts. Eur. Heart J. 34, 750–758 (2013).
  3. Ezdini, E. S. & Faraeen, M. Exercise and Sleep during Adolescence: Examining the Effects of Different Types of Physical Activity on Sleep Quality. KMAN Couns. Psychol. Nexus 3, 1–18 (2025).
  4. de Souza, I. K. C. et al. Polypharmacy, physical activity, and sedentary time in older adults: A scoping review. Exp. Gerontol. 183, 112317 (2023).
  5. Heissel, A. et al. Exercise as medicine for depressive symptoms? A systematic review and meta-analysis with meta-regression. Br. J. Sports Med. 57, 1049–1057 (2023).
  6. Foster, C. et al. The Effects of High Intensity Interval Training vs Steady State Training on Aerobic and Anaerobic Capacity. J. Sports Sci. Med. 14, 747–755 (2015).
  7. Li, R. et al. Associations of Muscle Mass and Strength with All-Cause Mortality among US Older Adults. Med. Sci. Sports Exerc. 50, 458–467 (2018).
  8. Araújo, C. G. S. et al. Muscle Power Versus Strength as a Predictor of Mortality in Middle-Aged and Older Men and Women. Mayo Clin. Proc. 100, 1319–1331 (2025).
  9. Zhao, F. et al. Optimal resistance training parameters for improving bone mineral density in postmenopausal women: a systematic review and meta-analysis. J. Orthop. Surg. 20, 523 (2025).
  10. Pisani, P. et al. Major osteoporotic fragility fractures: Risk factor updates and societal impact. World J. Orthop. 7, 171–181 (2016).
  11. AbouAssi, H. et al. The effects of aerobic, resistance, and combination training on insulin sensitivity and secretion in overweight adults from STRRIDE AT/RT: a randomized trial. J. Appl. Physiol. 118, 1474–1482 (2015).