As the world’s population continues to increase, the number of older adults is growing at an unprecedented rate. Improving quality of life during the aging process requires a collaborative effort between the individual and their healthcare team. Along with preventive care, social connections, smoking avoidance, and healthy eating, physical activity is key to healthy aging.

Aging Across the Globe

It is no surprise that life expectancy is vastly different today than it was in the 1780s, when a baby born in England had a life expectancy of 35 years, and in Massachusetts, only 28 years.¹

The fastest-growing population in the US today are those aged 65 years and older.² Perhaps more significant is the fact that the number of individuals aged 95 and older increased by 48.6% in the decade between 2010 and 2020.³

This increased growth rate is not unique to the US.₄ The World Health Organization reports that by 2050, the world’s population of those aged 60 and older will double from 1.4 billion to approximately 2.1 billion, and those aged 80 years and older will likely triple to an estimated 426 million.

Since aging is a risk factor for numerous pathologies, understanding the various processes associated with disease susceptibility and some of the cellular changes that occur with age is essential to addressing the ongoing healthcare needs of those who are aging.

Aging Gracefully

Various theories describe aging. Aging results from the overproduction of reactive oxygen species resulting in oxidative stress which damages the mitochondria.⁵ The wear and tear theory⁶ and various other genetic alterations⁷ also contribute to the changes evident with aging.

One of the most common cardiovascular manifestations of aging is arterial stiffness, which increases the workload of the heart and is a primary contributor to hypertension.⁸ With aging, the metabolism slows, increasing the risk for weight gain, decreases in muscle mass and strength (sarcopenia),⁹ decreases in cardiovascular fitness, and reductions in both the size and density of bones.¹⁰

Physical Activity is Key to Healthy Aging

Since physical degeneration cannot be prevented, the best approach may be to strive for a healthy lifestyle, such as through regular physical activity. Physical activity continues to be the best buy for public health; it is “just good medicine.”¹² The fact remains: exercise benefits prevent much of the typical age-related degeneration and coinciding chronic illnesses in older adults.¹³

Exercise improves cardiovascular function and prevents colon cancer, diabetes, obesity, and hypertension. It also improves muscular strength, weight management, immunity,¹² sleep, mental health, cognition, coordination, and flexibility.¹³

In spite of increased post-menopausal bone resorption to approximately 2% of annual bone mass, strength training restores bone density, counteracting resorption.¹³ Gallegher and colleagues¹⁴ observed fewer Alzheimer’s disease biomarkers in participants over 60 who performed 30 minutes of exercise every day. Research also demonstrates that only a single session of moderate-to-vigorous physical activity improves anxiety and depression.¹⁵ Moreover, these exercise-related benefits have been found to continue well into old age,¹⁶ with improved moods observed in men aged 65 and older following exercise engagement.

Physical Activity Slows and May Even Reverse Aging.

Grevendonk and colleagues¹⁸ recently examined the extent to which physical activity contributed to a decline in mitochondrial function and muscle health during aging by comparing mitochondrial function in young adults with older adults with similar physical activity habits. In spite of each age group maintaining adequate quantities of physical activity, age-related changes were found to include a decline in mitochondrial capacity, exercise capacity and efficiency, gait stability, muscle function, and insulin sensitivity. When physical activity levels were increased through regular exercise training, certain effects of aging were prevented.¹⁸

Taking it one step further, Jones and colleagues¹⁷ investigated how exercise alone affects gene expression in the muscle fibers of older mice and humans. The researchers compared the effects of Oct3/4, Klf4, Sox2, and Myc – four transcription factors collectively referred to as OKSM. OKSM was examined on gene expression in 22-month-old mice, equivalent to 73 years in an adult human. Mice who were able to exercise on a wheel were compared with mice who did not have wheel access. The researchers found the OKSM changed mature cells to younger cells, or pluripotent stem cells from increased gene expression, due to exercise inducing expression of Myc more than the other factors, thereby reprogramming the muscle fibers to a more youthful state.¹⁹ They concluded that regular physical activity delays typical age-related changes, potentially preventing aging¹⁸ through epigenetic reprogramming of chromosomes in the nuclei of muscle cells.¹⁹

Exercise recommendations for older adults: tips for success

The Physical Activity Guideline provides recommendations¹⁹ for older adults 65 years and older. These include at least 150 minutes of moderate-intensity activity, such as brisk walking (30 minutes a day, 5 days a week), or 75 minutes a week of vigorous-intensity activity (e.g., hiking, jogging, running).

Consistent with these recommendations, The National Council on Aging recommends that older adults include aerobic activity, strength training, and flexibility exercises in their workouts.²⁰ Exercises such as Pilates, yoga, aerobic exercise, and strength training are gentle on the joints while enhancing strength, stabilizing the core, improving flexibility, and strengthening bones. Aerobic exercises like walking, swimming, and biking (in older adults, the stationary bike) improve fitness and stamina, whereas core strength improves balance and stability. Low-impact activities that may improve strength include push-ups performed against a wall, climbing stairs, single-leg stands, weights of 1 to 2 lbs., or resistance bands.

Where to Begin with Physical Activity?

The following tips may be useful when beginning a physical activity regimen:

• Exercise at the same time each day.
• Perform muscle strengthening exercises, balance, and coordination (e.g., standing on one foot) at least twice a week.
• Find an enjoyable location to enhance sustainability, such as a bike path, forest preserve, or scenic route.
• To prevent injuries, start slowly and increase according to how the body responds.
• Explore options for indoor exercise classes, apps, or online videos during unseasonable weather or to incorporate variety.
• Exercise with friends, family, or group classes for increased social support.
• Record progress through an app or physical activity diary.

While physical activity engagement in older adults varies according to preference, ability, and resources, it does not have to be an all-or-nothing effort; even minimal quantities are beneficial, and any amount is better than nothing at all.²¹

Resources on Physical Activity and Health Aging

• The National Institute of Aging provides helpful information for older adults engaging in exercise and physical activity.
• Behavior Change Mini-Certificate – 3.5 CE contact hour course to help to apply tools and intervention strategies for working with patients in cardiovascular disease behavior change.
• Heart Healthy Toolbox – a series of lifestyle change patient education tools that includes 8 sheets on physical activity.

References

1. National Institutes of Health. Aging: The Biology of Senescence. 2000.
2. US Census Bureau. 2020 Census: 1 in 6 People in the United States Were 65 and Older. 2023. Accessed 5 December 2023.
3. US Census Bureau, 2023. 2020 Census: 1 in 6 People in the United States Were 65 and Over. Accessed 5 December 2023.
4. WHO. Ageing and Health. 2023. Accessed 20 December 2023.
5. Shigenaga MK, Hagen TM, Ames BN. Oxidative damage and mitochondrial decay in aging. Proc Natl Acad Sci U S A. 1994;91(23):10771-10778. doi:10.1073/pnas.91.23.10771
6. Szilard L. On the nature of the aging process. Proc. Natl. Acad. Sci. USA. 1959; 45:30–45.
7. Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Aging: The Biology of Senescence.
8. Boutouyrie P, Chowienczyk P, Humphrey JD, Mitchell GF. Arterial Stiffness and Cardiovascular Risk in Hypertension. Circ Res. 2021;128(7):864-886. doi:10.1161/CIRCRESAHA.121.318061
9. Hosam K. Kamel, Sarcopenia and Aging, Nutrition Reviews. 2003;61(5):157–167,
10. Padilla Colón CJ, Molina-Vicenty IL, Frontera-Rodríguez M, et al. Muscle and Bone Mass Loss in the Elderly Population: Advances in diagnosis and treatment. Journal of Biomedicine. 2018;3:40–49.
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12. Ezzatvar Y, Ramírez-Vélez R, Izquierdo M, Garcia-Hermoso A. Physical activity and risk of infection, severity and mortality of COVID-19: a systematic review and non-linear dose-response meta-analysis of data from 1 853 610 adults. British Journal of Sports Medicine. 2022;56:1188-1193.
13. Benedetti MG, Furlini G, Zati A, Letizia Mauro, G. The Effectiveness of Physical Exercise on Bone Density in Osteoporotic Patients. BioMed research international. 2018, 4840531.
14. Gallagher M, Okonkwo OC, Resnick SM, Jagust WJ, Benzinger TLS, Rapp PR. What are the threats to successful brain and cognitive aging? Neurobiol Aging. 2019;83:130-134. doi:10.1016/j.neurobiolaging.2019.04.016
15. Petit R, Henert S, Moxley E, Kowal R. (2023, Fall). Combining MVPA and Motivational Strategies to Improve the Mental Health and Well-Being of Sedentary Middle-Aged Adults. [Poster presentation]. 2023 Midwest ACSM Regional Chapter Fall Meeting, Indianapolis, IN, United States.
16. Grevendonk L, Connell NJ, McCrum C. et al. Impact of aging and exercise on skeletal muscle mitochondrial capacity, energy metabolism, and physical function. Nat Commun. 2012;12, 4773.
17. Jones RG 3rd, Dimet-Wiley A, Haghani A, et al. A molecular signature defining exercise adaptation with ageing and in vivo partial reprogramming in skeletal muscle. J Physiol. 2023;601(4):763-782. doi:10.1113/JP283836
18. Omole AE, Fakoya AOJ. Ten years of progress and promise of induced pluripotent stem cells: historical origins, characteristics, mechanisms, limitations, and potential applications. PeerJ. 2018;6:e4370. doi:10.7717/peerj.4370
19. U.S. Department of Health and Human Services. 2018. Physical Activity Guidelines for Americans (2nd ed.).
20. National Council on Aging, 2023. Accessed 20 December 2023.
21. Moxley E, & Habtzghi D. A comparison of exercise dose response: A systematic review. Home Health Care Management & Practice. 2018 31(4):263-273.