Often when I talk to seniors and discuss exercise, I find that far too many think the only activity they need to do is walk. This is an unfortunate misunderstanding of the importance of exercise and the breadth of the body's need for exercise variety. No particular exercise whether it be strength training, cardiovascular, stretching, or movement, i.e., dance or Tai Chi, can alone meet all the myriad needs of the body.
Walking is indeed an excellent exercise for the human body and research has confirmed that it is beneficial in several significant ways. A recent article on walking in the Harvard Health Publishing newsletter discusses “five surprising benefits of walking” discovered as a result of that research.
In one study of over 1,200 subjects Harvard researchers found walking suppressed the obesity promoting activities of some 32 separate genes. This change in gene expression, called epigenetics, can happen as a result of lifestyle changes like exercising or even changes in environment. Just 15 minutes of walking was found to be effective at reducing chocolate cravings by two separate studies conducted at the University of Exeter. Walking seven or more hours a week was found to reduce breast cancer risk by as much as 14% according to an American Cancer Society study that looked at the effectiveness of walking. With regard to arthritis, several studies have found that walking will reduce arthritic pain and walking five or six miles per week can even halt the development of arthritis by keeping the cartilage in the joints lubricated and supplied with nutrition. The immune system benefits from walking as well, as one study of over 1,000 individuals found that those who walked at least five days a week for 20 minutes had 43% fewer sick days.
So, the benefit of walking is eminently clear and without dispute. But as pointed out in a recent AARP article, good habits done exclusively “might actually age you prematurely.” Many people as they get older opt to do walking and nothing else because they fear injury from lifting weights or even jogging. As a 65-year-old certified senior fitness specialist, I see this all the time, but it's important to understand that we actually start losing muscle strength and mass as early as 30 to 35 years of age. One of the greatest contributors to injury and even death from senior falls is muscle weakness, its subsequent inability to correct one's balance or stability as a result of a misstep or stumble.
Regarding the onset of osteoporosis, it is also important to realize that as go the muscles so go the bones, i.e., as the muscles get weak the bones follow suit. Yet conversely as the muscles get stronger the bones do as well. As much as one might think that walking increases the strength of muscles and bones it's not enough especially as we get older. Because walking alone just can't keep up with the accelerated loss of bone mineral density as we age. In fact, a study published in the International Journal of Obesity looking at mail carriers in Glasgow, Scotland who covered most of their routes on foot, found that the standard of 10,000 steps per day was also insufficient for cardiovascular health. It's believed that one of the reasons this recommendation is no longer effective is because diets today are significantly different than back in the 1960’s when this metric was first introduced by Dr. Yoshiro Hatano, who was then a professor at Kyushu University of Health and Welfare in Nobeoka, Japan.
Research shows that people who also include strength training in their exercise regimen with their aerobics or cardiovascular fitness training live longer and better lives. In a 2022 study published in the British Journal of Sports Medicine the researchers found that both aerobic and strength exercise were independently associated with lower risk of dying during the study time frame. Yet most important was the discovery that combining both cardiovascular and strength exercise in your regimen synergistically lowered the rate of mortality risk. This study looked at a massive cohort of over 416,420 individuals recruited in the US between 1997 and 2014. By using National Health interview survey data, they were able to find out how many of these individuals participated in moderate or vigorous exercise that included muscle strength training exercises during the week. After adjusting for the usual cofactors that could affect the data, such as age, income, education, marital status, and so forth, those who engage in one hour of moderate to vigorous aerobic activity a week had a 15% lower mortality risk. Mortality risk was 27% lower for those who did three hours a week. But those who included one to two hours of strength training sessions per week had an even lower mortality risk of 38 to 40% respectively.
Yet this isn't the only study that found the benefits of strength training affecting unexpected areas of the body. As we grow older, neurological lesions may develop in the white matter of our brains negatively affecting our cognitive skills and abilities as we grow older. Most of the research on exercise being beneficial for the brain has centered on the benefits of aerobics, and indeed aerobics has been found to be very beneficial as a result of the increased oxygenated blood flowing to the brain during aerobic exercise nourishing the brain tissue. But Dr. Teresa Liu-Ambrose, professor of Physical Therapy and Director of the Aging, Mobility, and Cognitive Neuroscience Laboratory at the University of British Columbia in Vancouver, wanted to find out if strength training would also be beneficial for the white matter of the brain. Dr. Ambrose reasoned that since strength training can rebuild muscle loss due to age related sarcopenia, which is often reflected in the shrinkage of our brains resulting in balance and gait issues, maybe it was possible for strength training to reverse that process in the white matter of the brain as a result of its involvement in the preservation of muscle, i.e., strength training as a holistic modulator of human growth hormone and subsequent remodeling.
Dr. Ambrose and her fellow scientists focused on 54 women between the ages of 65 and 75 who were already enrolled in brain health studies and had shown signs of existing white matter lesions. Testing gate stability and so forth they were randomly assigned to different one of three groups with one group focusing on balancing and flexibility exercises, another strength training once per week, and the third group assigned strength training twice per week. At the end of one year the women who focused on balance and flexibility had significant progression in the number and size of their lesions, so did the women who did weight training once per week. The women who lifted twice a week also had lesions, but they were significantly fewer and smaller than those in the other two groups. When tested for their gait and stability they were found to walked more quickly and smoothly than the women in the other two groups. This was the first-time strength training was found to have a direct impact on the progression of white matter lesions in the human brain.
So, in conclusion walking alone, though a wonderful exercise, is not sufficient to garner or even support good health and fitness, especially for older adults. Walking by itself is not sufficient to meet the load bearing needs of muscles and subsequent bones to avert the progressive onset of sarcopenia and osteoporosis. If walking is all you have resolved to do, know it will not provide sufficient challenge to the muscles and nervous system to provide them with the stimulus necessary to help you maintain good balance and stability as you age. If you are uncomfortable lifting weights then you should employ the assistance of a Certified Fitness Professional to help you slowly progress from where you are to where you need to be in the strengthening of your body and the maintaining of your independent lifestyle.
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