A scientific study by researchers at Harvard University in the United States debunked a myth about older people. Many believed it necessary to slow down the pace of physical activity as people pass 60 years of age. But the truth is that the body should not retire from physical activity, and the researchers’ work provided evidence showing that stopping from being on a couch all day or moving around in transportation instead of walking can be beneficial to living longer and well.
The study was published in the specialized journal PNAS published by the United States Academy of Sciences. It presents evolutionary and biomedical evidence showing that humans evolved to live many decades after reproducing and to be relatively active in their later years.
The researchers state that physical activity in old age diverts energy from processes that can compromise health and directs it towards the body’s mechanisms that prolong it. Their hypothesis – which they call the “active grandmother hypothesis” – is that humans evolved to stay physically active as they age.
In doing so, energy is allocated to physiological processes that slow down the gradual deterioration of the body over the years. This protects against chronic diseases such as cardiovascular disease, type 2 diabetes, and even some cancers.
“In western societies it is widespread the idea that, as we age, it is normal to slow down, do less and retire, “said Harvard University evolutionary biologist Daniel Lieberman, lead author of the paper. “Our message is the opposite: As we get older, it is even more important to be physically active ”.
The research team, which includes Aaron Baggish and I-Min Lee of Harvard Medical School, believe the work is the first detailed evolutionary explanation for why a lack of physical activity as humans age increases physical activity. risk of disease and reduces longevity. Baggish, 47, who is also a cardiologist for the New England Patriots football team. The lead author, Lieberman, is 57 years old, and They are long-time running buddies and often discuss the ideas in the article during morning runs of 8 to 16 kilometers.
Study uses human human ape cousins as a starting point. The researchers note that apes, which typically live for only 35 to 40 years in the wild and rarely survive past menopause, are considerably less active than most humans. This suggests that in human evolution there was selection not only to live longer, but also to be more physically active.
According to Lieberman, human beings evolved from ancestors that were sedentary. He has twice observed wild chimpanzees in Tanzania and has been amazed at the amount of time they spend a day “sitting on their backs, digesting.”
This is especially surprising when compared to contemporary hunter-gatherers, who engage in an average of 135 minutes of moderate or vigorous physical activity per day. That level of movement – between six and ten times the average for Americans – may be one of the keys to why hunter-gatherers who survive infancy tend to live for about seven decades, roughly 20 years past the age when humans typically stop having children.
Fossil evidence indicates that this prolongation of life was common 40,000 years ago, contrary to the belief that human life was short until recently. The team stressed that the main health benefit of physical activity is the prolongation of human life expectancy, which is defined as the years of life spent in good health.
The researchers examined two pathways by which physical activity throughout life reallocates energy to improve health. The first is to steer excess energy away from potentially damaging mechanisms, such as fat storage. The team also identified how physical activity allocates energy to repair and maintenance processes. The work shows that, in addition to burning calories, physical activity is physiologically stressful and causes damage to the body at the molecular, cellular and tissue levels.
However, the body’s response to this damage is essentially to rebuild itself stronger. This includes repairing muscle fiber tears, repairing cartilage damage, and healing microfractures. The response also triggers the release of exercise-related antioxidants and anti-inflammatories, and improves blood flow. In contrast, when physical activity is not performed, those responses are less activated. Cellular and DNA repair processes have been shown to reduce the risk of diabetes, obesity, cancer, osteoporosis, Alzheimer’s disease, and depression.
“The key point to keep in mind is that as we evolve to be active throughout our lives, our bodies need physical activity to age well. In the past, daily physical activity was necessary to survive, but today we have to choose to exercise, that is, voluntary physical activity for the sake of health and fitness, ”said Lieberman.
The research team, which includes graduate students Timothy Kistner and Daniel Richard, hopes the study will make this message harder to ignore. Because the increase in sedentary lifestyle is worrisome globally. Levels of physical activity have declined around the world as machines and technology replace human work.
Another recent study from Lieberman’s lab showed that Americans get less physical activity than 200 years ago. Researchers’ advice based on scientific studies? You have to get up from the chair and do some exercise. “The key is to do something, and try to make it enjoyable so that you keep doing it,” Lieberman said. “The good news is that you don’t have to be as active as a hunter-gatherer. Even small amounts of physical activity – just 10 to 20 minutes a day – substantially reduce the risk of mortality, “he added.
Almost everyone knows that exercise is good for your health. Some people may even list the reasons why it keeps muscles and joints strong, and how it fights certain diseases. But Lieberman’s research explained why and how physical activity was incorporated into human biology.
One of the physical activities The most recommended is the brisk walk. You should take a brisk walk 150 minutes per week, as recommended by the WHO. The ideal is to walk briskly 45 minutes every other day. When you count, you will be walking for more than 150 minutes a week.
In the case of being overweight, walks are also indicated. Dr. Silvio Schraier, deputy director of the Barceló Foundation specialization in nutrition in Argentina, recommended: “Ideally, you should walk 10,000 steps per day, which can be measured with any mobile phone app,” he said. And he remarked that you have to be patient to observe the weight loss.