Exercise is good for us, we know that. From managing a healthy body weight to reducing the risk of heart disease to lowering cholesterol to rehabilitating an injury, exercise can deliver a wide variety of health benefits. However, one of the things that we’re still learning is how exercise affects the human aging process. Time keeps on slipping into the future, which is why an extensive amount of the research in the field of exercise science is attempting to understand how physical activity affects the human aging process. Medical professionals once thought that older adults might be too frail for exercise in general, let alone participate in high-intensity exercise. Now that we’re entering the third decade of the 21st century, there exists a large population of older adults who not only have been exercising their entire lives but also have the ability to do so at a high intensity.
The result is that exercise science researchers now have the opportunity to study older adults who have been physically active by participating in regular exercise throughout the majority of their life span. Scientists are discovering many new insights about how consistent exercise could benefit us as we ebb into our later years. They are learning that not only is regular exercise good for us as we age, but that high-intensity exercise, once thought of as way too strenuous for older adults, also may provide important benefits. To help you understand what science is learning about exercise and the aging process, a number of brief research reviews are listed below.
Consistent cardiovascular exercise can slow down effects of aging
In a recent study titled “Cardiovascular and Skeletal Muscle Health With Lifelong Exercise” conducted by the Human Performance Laboratory at Ball State University in Indiana, researchers studied a group of adults who have been exercising for 50 years and compared their physiology to two other groups: adults in their 20s and older adults the same age who were physically active but did not exercise consistently. Both groups of older adults were in their 70s. The older adult exercise group (OAEG) reported exercising an average of five days per week, accumulating seven hours of exercise a week since the first exercise boom in the 1970s, while the other group of older adults (OA) reported being active but did not exercise regularly. The younger adults (YA) reported exercising the same approximate amount as the OAEG.
Running was the primary form of exercise reported by the OAEG, and researchers further classified them into two subgroups: those who participated in moderate exercise and those who competed in racing events classified as vigorous exercise. All groups in the study—OA, OAEG and YA—visited the Ball State lab nine times for a series of tests and the findings were remarkable. The scientists studied the maximum oxygen consumption (VO2 max) and muscle capillarization of all groups. Muscle capillaries are where oxygen is exchanged into the muscle tissue. A greater density is a marker of good health. As the study authors note, preservation of capillaries may “provide benefits for athletic performance and skeletal muscle health by enhancing blood flow to muscle for increased oxygen delivery.” VO2 max measures how efficiently the body uses oxygen. This is important because a loss of VO2 is a risk factor for early death.
Not surprisingly, the OAEG demonstrated a better VO2 than the OA of the same age, which indicates they have a lower risk of early death when compared to those who did not exercise over that timespan. Those who participated in vigorous exercise over their life span had better VO2, indicating the benefits of exercise at higher intensities. However, the scientists were surprised to find the OAEG had almost no difference in capillarization when compared to the YA almost 50 years younger. These findings suggest that continuous aerobic exercise over the course of the adult life span could provide substantial health benefits for adults in their 70s and beyond, as well as literally freezing muscle in time, helping it to appear and behave like tissue many years younger.
Trappe, S. et al., (2018) Cardiovascular and skeletal muscle health with lifelong exercise. Journal of Applied Physiology (2018).125: 1636 – 1645.
Listen to an interview with Scott Trappe, Ph.D., director of the Human Performance Laboratory at Ball State University and the lead author of the study, on that “All About Fitness” podcast.
High-intensity interval training may provide greater health benefits for older adults than moderate-intensity continuous training
One of the most significant impacts of the aging process on human physiological functions is a decline in the ability of the heart to pump oxygenated blood to the muscles. Because it can improve aerobic capacity while burning a lot of calories, high-intensity interval training (HIIT) has been credited with a number of health benefits, including improving cardiac function and aerobic capacity. However, one challenge for the ability of older adults to participate in HIIT that could provide important benefits is finding an appropriate mode of exercise. For example, running on the moving surface of a treadmill could cause overuse injuries while increasing the risk of a fall. A team of scientists from Korea and the United States collaborated to study whether sedentary older adults could improve aerobic capacity and other markers of health by performing HIIT on a stationary cycle ergometer with moving arms. The benefit of using a cycle ergometer with upper-body movements (commonly called an “Assault bike”) is that because more muscle mass is involved in the exercise activity, the cardiorespiratory system has to work harder to pump oxygenated blood to the working muscles. The use of sedentary adults was important because it demonstrates that HIIT could be safe for individuals without an extensive history of exercise.
This study compared two groups of older adults with an average age of 65. One group used the cycle ergometer with moving arms for four, four minute bouts of high-intensity exercise at 90 percent of peak heart rate (with a three-minute recovery interval between each high-intensity bout), while the other group performed 32 minutes of continuous exercise at 70 percent of peak heart rate on the same equipment. When the warm-up and cool-down periods were included, the high-intensity group did a total of 40 minutes of exercise, while the moderate-intensity group exercised for a total of 47 minutes. After the eight-week study period, the study authors observed that the HIIT group experienced an 11 percent improvement in aerobic capacity when compared to the continuous group, which experienced no changes. The HIIT group also experienced a decrease in insulin resistance, an important metric in the fight against onset diabetes. Again, the continuous group did not experience any change in insulin resistance after the study period. The evidence collected in this study suggest that HIIT may be more effective for older adults when compared to steady-state, continuous aerobic exercise.
Hwang, CL. et al. (2016) Novel All-Extremity High-Intensity Interval Training Improves Aerobic Fitness, Cardiac Function and Insulin Resistance in Healthy Older Adults. Experimental Gerontology; 82: 112-119.
Aerobic exercise could help improve memory in older adults
In a study published in the journal Applied Physiology, Nutrition, and Metabolism, a team at McMaster University in Canada found that older adults who participated in high-intensity interval training workouts experienced up to 30 percent improvements in short-term memory, while participants in moderate-intensity exercise did not experience the same outcomes. The study group included older adults between the ages of 60 and 88 who exercised three times a week for 12 weeks. “It’s never too late to get the brain benefits of being physically active, but if you are starting late and want to see results fast, our research suggests you may need to increase the intensity of your exercise,” states Jennifer Heisz, Ph.D., an associate professor in the Department of Kinesiology at McMaster University and lead author of the study.
The effects of aerobic exercise intensity on memory in older adults; Applied Physiology, Nutrition, and Metabolism. Published October 30, 2019.
Exercise can improve the mental health of older adults
It is well-known that exercise is good for the physiological systems of the body regardless of age. This past year, research was published in the American Journal of Physiology-Cell Physiology, which suggests that exercise can help support mental health, as well, by helping reduce the risk of depression in older adults. It is well-known that exercise can change the levels of neurotransmitters that can affect our overall mental health. The study sought to answer the question about whether sarcopenia (the loss of muscle mass) that occurs during aging would affect the ability to use exercise as a treatment for depression in older adults. The study included men older than 65 who participated in high-intensity workouts over the course of the 12-week study period. The results suggest that older adults who participate in regular exercise could experience benefits for mental health even when older than 65.
Exercises training impacts skeletal muscle gene expression related to the kynurenine pathway; American Journal of Physiology-Cell Physiology. Published March 2019.
Exercise could improve cognitive function in older adults
A team from the University of Iowa found that even a single bout of exercise can change brain function in older adults. In experiments that included exercise, brain imagery and memory tests, the study participants showed that exercise can help improve memory in the short term and for the long run. The brain scans were able to show how one bout of physical activity could have an immediate impact on the function of the organ, which could help develop further understandings of the relationship between exercise and recall memory. This provides further evidence that regular physical activity not only can change the physiological functions of the body but also can help improve cognitive performance of the brain, even during the latter years of the aging process.
Acute exercise effects predict training change in cognition and connectivity; Medicine & Science in Sports & Exercise. Published August 2019.
Position statement on resistance training for older adults
In 2019, the National Strength and Conditioning Association updated its position statement on the benefits of resistance training for older adults. The position statement relies on evidence published in peer-reviewed journals to encourage older adults to participate in resistance training for a variety of health benefits. Resistance training can help older adults increase lean muscle mass, improve functional strength for activities of daily living and help enhance overall quality of life. “The goal if this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults,” says a statement released by the National Strength and Conditioning Association.
Resistance Training for Older Adults—Position Statement by the National Strength and Conditioning Association; Journal of Strength and Conditioning Research. Published August 2019.
These are only a few brief reviews featuring the benefits of exercise on the aging process. Instead of going to the gym to get swole or burn calories, you will now go with the knowledge that what you are about to do could counteract the effects of aging while significantly adding to the quality of your life as time continues slipping into the future.
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