Canada’s population is getting older, with almost 1 in 5 Canadians now over the age of 65, according to Statistics Canada.1 As we age, our bodies go through a variety of changes, and things that once felt easy can start to feel more challenging. The good news? Staying active can work wonders — helping us stay independent and feeling good well into our later years.
With that in mind, let’s take a closer look at how aging affects the cardiorespiratory system, and how exercise plays a powerful role in maintaining its health.
Cardiovascular Changes with Age
While resting cardiovascular function often remains relatively stable, both the heart and blood vessels undergo notable structural and functional changes than can impact how to body responds to exercise stress:
- The left ventricular wall thickens, and myocardial contractility (the heart’s ability to contract efficiently) declines.2
- Arteries lose elasticity and the inner layers of their walls thicken, increasing resistance to blood flow.2
- This increased resistance contributes to higher blood pressure and makes it harder for the heart to pump blood effectively — especially during physical activity.
- As a result, blood flow to working muscles is reduced, making it harder for the body to meet the demands of exercise.2
A major contributor to this decline is the decrease in maximum heart rate, which drops by about 6–10 beats per minute per decade after age 20. On top of that, mitochondrial function — critical for energy production — declines, lowering the maximal oxygen uptake (VO₂ max) and reducing endurance. Blood lipid profiles may also shift with age, with total cholesterol increasing and HDL (the “good” cholesterol) decreasing.2
Respiratory Changes with Age
Aging also impacts the respiratory system:
- There’s a gradual loss of lung tissue elasticity and stiffening of the chest wall.2
- Bronchioles narrow, and lung volume capacity decreases.
- These changes can lead to dyspnea (shortness of breath), particularly during exertion.2
VO₂ Max and the Aging Process
Maximal oxygen consumption (VO₂ max) is a widely recognized indicator of cardiovascular fitness. Starting around the age of 25, VO₂ max tends to decline by approximately 10% per decade. Among healthy but moderately active older adults, the average VO₂ max is about 21 mL·kg⁻¹·min⁻¹ (half of that of a young adult).2
This number matters—a lot. VO₂ max is a key factor in preserving health, mobility, and independence as we age. Research indicates that a VO₂ max of at least 16 mL·kg⁻¹·min⁻¹ is needed to remain functionally independent in daily life. To put that in perspective, even a routine chore like vacuuming can demand roughly 18 mL·kg⁻¹·min⁻¹ of oxygen—making it surprisingly taxing for individuals with low aerobic fitness.2
How Exercise Helps the Aging Heart and Lungs
Exercise is one of the most effective tools we have to counter the effects of aging on the cardiorespiratory system. A number of studies highlight just how powerful regular physical activity can be, especially in older adults.
Exercise and Heart Health in Older Adults with Hypertension
A study titled “Effect of Endurance Exercise Training on Left Ventricular Size and Remodeling in Older Adults with Hypertension” explored whether regular endurance training could reduce blood pressure and improve heart structure in older adults with mild to moderate hypertension.
- Participants: 11 older adults (average age 65.5) completed about 6.8 months of endurance training, while 7 others (average age 68.5) remained sedentary as a control group.
- Results: The exercise group saw:
- A 16% increase in VO₂ max
- Significant reductions in both systolic and diastolic blood pressure
- A decrease in left ventricular wall thickness, suggesting a partial reversal of heart muscle thickening (left ventricular hypertrophy or LVH)
- These improvements were not seen in the control group.
The study concluded that regular endurance exercise can effectively lower blood pressure and improve heart structure in older adults, even in the presence of hypertension.3
Aerobic Training Boosts VO₂ Max
A meta-analysis examining the effects of aerobic exercise on VO₂ max in sedentary older adults reinforces the cardiovascular benefits of staying active. This analysis included 41 controlled studies with 2,102 participants aged 60 and older.
- Key findings:
- Endurance training improved VO₂ max by an average of 3.78 mL·kg⁻¹·min⁻¹
- The most significant improvements occurred when:
- Training lasted more than 20 weeks
- Intensity was between 60–70% of VO₂ max
These results emphasize that duration and intensity matter—longer, moderately intense programs lead to the greatest improvements in aerobic capacity and, by extension, heart health and independence.4
Exercise and Metabolic Health
The study “Exercise and Risk Factors Associated with Metabolic Syndrome in Older Adults” examined how cardiorespiratory fitness influences blood lipid levels.
- Participants who improved their fitness through exercise showed:
- Higher HDL (“good”) cholesterol
- Lower triglyceride levels
- Slight but positive trends in lowering LDL (“bad”) cholesterol
Interestingly, the most meaningful changes in lipid profiles were seen in participants who achieved significant gains in VO₂ max, reinforcing the idea that fitness improvements—not just exercise alone—drive better metabolic outcomes.5
The Bottom Line
Exercise doesn’t just help older adults feel better—it directly improves heart structure, lowers blood pressure, boosts aerobic capacity, and supports healthier cholesterol levels. The more consistent and appropriately intense the exercise, the greater the benefits, making it a cornerstone of healthy aging.
References
- Statistics Canada. “Older Adults and Population Aging Statistics.” Www.statcan.gc.ca, 8 Feb. 2019, http://www.statcan.gc.ca/en/subjects-start/older_adults_and_population_aging.
- Canadian Society For Exercise Physiology (2021). Canadian Society for Exercise Physiology-Physical Activity Training for Health (CSEP-PATH). Ottawa, On: Canadian Society For Exercise Physiology.
- Turner, M.J., Spina, R.J., Kohrt, W.M. and Ehsani, A.A. (2000). Effect of Endurance Exercise Training on Left Ventricular Size and Remodeling in Older Adults With Hypertension. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, [online] 55(4), pp.M245–M251. doi:https://doi.org/10.1093/gerona/55.4.m245.
- Huang, G., Gibson, C.A., Tran, Z.V. and Osness, W.H. (2005). Controlled Endurance Exercise Training and VO 2max Changes in Older Adults: A Meta‐Analysis. Preventive Cardiology, 8(4), pp.217–225. doi:https://doi.org/10.1111/j.0197-3118.2005.04324.x.
- Stewart, K.J., Bacher, A.C., Turner, K., Lim, J.G., Hees, P.S., Shapiro, E.P., Tayback, M. and Ouyang, P. (2005). Exercise and risk factors associated with metabolic syndrome in older adults. American Journal of Preventive Medicine, 28(1), pp.9–18. doi:https://doi.org/10.1016/j.amepre.2004.09.006.
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