How Evolution Shapes Our Need for Movement in Midlife and Beyond
What modern life gets wrong about exercise (and what our ancestors got right)
Have you seen the Canadian advertisement that asks the question:
"What will your last 10 years look like?"
The ad shows side-by-side images of an older man—one where he's active and vibrant, the other where he’s in a nursing home being fed. The message is clear:
"Will you grow old with vitality? Or get old with disease? It’s time to decide."
The point being made is that exercise is the key to maintaining vitality as we age, especially those last 10 years.
To be honest, I’m not sure how I feel about this ad. Yet, there’s no denying that exercise is a foundational component of our health and well-being, especially as we grow older.
But before diving into posts about the specifics of exercise, I want to take a step back to explore the why.
Defining exercise
There is no single definition for physical activity and exercise. In this older study in Public Health Reports, researchers define physical activity as "any bodily movement produced by skeletal muscles that results in energy expenditure."
Physical activity is simply part of being human, whether it be everyday activities like work, household chores, or anything we do in our leisure-time.
Exercise, according to the same researchers, is “a subset of physical activity that is planned, structured, and repetitive and has as a final or an intermediate objective the improvement or maintenance of physical fitness.”
In other words, while all exercise is physical activity, not all physical activity is exercise. Yet as we age, overal physical activity decreases by 40-80%.
And this occurs more so in women, as researchers from this 2018 study in the Journal of Frailty and Aging noted:
Older men had higher levels and greater frequency of moderate-to-vigorous intensity physical activity, and higher frequency of exercising outside the home. Both levels and frequencies of physical activity decreased with age, especially for daily step counts and frequency of performing physical activity outside the home.
It wasn’t always this way. For most of human history, midlife and older people maintained highly physical active lives. This gives us clues why it’s so important for both health and longevity.
The Active Grandparent Hypothesis
In a 2021 piece published in the Proceedings of the National Academy of Sciences of the United States of America, researchers suggest that a significant increase in physical activity began around 2 million years ago with hunting and gathering. This shift was key to extending human lifespans.
While average lifespans were shorter in prehistoric times, those who survived childhood often lived 20 years beyond their reproductive years. Fossil evidence shows that longer lifespans became more common around 40,000 years ago.
The Active Grandparent Hypothesis posits that grandparents, freed from the responsibilities of child-rearing, were physically active foragers who contributed by hunting and gathering food for their families.
For example, post-menopausal, modern-day Hazda hunter-gatherers reportedly spend an average of 6 hours a day foraging, 20% more than younger mothers. This means they spend much of their day walking, digging, running, and carrying heavy loads.
The researchers put it this way:
All animals need to engage in regular PA but, at some point, hominins were selected to engage in significantly more PA than their comparatively sedentary ancestors to make possible our unique life-history strategy in which parents and grandparents gather and hunt surplus energy which they transfer to their children and grandchildren. A key component of this energetically intensive strategy is for postreproductive adults to stay healthy for several decades as they continue engaging in PA.
How this connects to health
The researchers argue that physical activity is a key driver of healthy aging because it stresses the body in ways that promote repair and maintain function.
Altogether, PA stimulates the body to allocate energy in ways that slow senescence and prevent morbidity from CVD, many cancers, and numerous other chronic illnesses such as type 2 diabetes and Alzheimer’s.
The evidence behind physical activity and exercise is undeniable and helps explain why a combination of both endurance and strength type of exercise is beneficial, stressing the body in different ways.
Yet for our ancestors, this was simply what they did not the physical activity and structured “exercise” we think of today. Modern times have not only changed that, but have messed with our heads a bit.
Normalizing movement vs. making it a chore
I didn’t plan to write about this topic, but I found the Active Grandparent Hypothesis and the Canadian ad fascinating.
Today, physical activity has been turned into a choice—something to be scheduled into our busy lives. This choice can often feel like a chore and our relationship to it is not always healthy.
As the researchers highlight in this piece, exercise is not a cure-all for health and longevity but a normal, healthy form of physiological stress. The same way we think of hunger or exposing a child’s immune system to various challenges.
It’s a much better way of thinking about it, do you think?
Yet using fear to get people moving - like the Canadian ad does - is rarely the answer. We already scare midlife women into a certain brand of exercise, and I think this misses the point.
Unlike our ancestors, physical activity can look different for everyone.
While we have more choices now than ever to be active, this comes with its own set of challenges. But ultimately, choice is better than no choice.
Even more important, we need to make these decisions from solid information, which I plan to provide.
So, I’d love to hear from you:
What are your biggest exercise-related questions?
What barriers do you face?
Are you satisfied with this part of your health routine?
What aspect of midlife exercise confuses you the most?
And what do you think about that scary Canadian Ad?
Let’s continue the conversation in the comments!
Thanks Maryann for yet another brilliant article. It's a very powerful and confronting ad for sure. Being in Australia, I hadn’t seen it. But I will share it. As confronting as it is, behind it is a very real message and a conversation we can not ignore. Particularly with an aging population. My Dad has dementia so this is very real for me - seeing him go from a healthy, very active, unmedicated man up until his bowel cancer and treatment to the person now almost unable to rise up out of a chair. I'd like to see a study on the impacts of chemotherapy on brain health. Thanks again MJ. Anita xx
I think so often in mid-life, it's easy to pretend that we are invincible. That we won't have mobility problems in our later years, or fall and need our hips replaced. And because so many of us are sleep deprived, making time for exercise feels like another chore on an already long to-do list. But the time for preventing those mobility problems and hip replacements starts now. The Canadian ad is sobering to say the least. And while I agree that fear is not the best way to motivate people to make changes, it's definitely a poignant reminder of what can happen if we don't see movement/exercise as a luxury we deserve, or a gift to our future self. Great article!