The old saying “use it or lose it” very much applies to reducing the impact that aging has on the mind and body. Of all the things we can do right now to help stay healthy as we grow older, exercise is probably the most useful.
Supplements have questionable results in humans, and none can really be described as geroprotective due to the lack of data. However, lifestyle and diet are very important in how we age, and caloric restriction has shown some interesting benefits in multiple species, including humans.
However, of all these things, exercise is probably the most important, and staying active can greatly influence our trajectory towards frailty in old age. Many people do not get the exercise they need as they age and, as a result, this can influence how well they age. Certainly, some level of age-related frailty may be a case of neglect and not exercising enough.
We are designed for physical activity
Our ancestors benefitted from a life that demanded intense physical activity in order to survive being hunter-gatherers. Their lifestyle required lots of travelling during the hunt for food and water.
If we look at modern-day hunter-gatherer tribes, such as the Hadza people in the Rift Valley area of East Africa, we get an idea of what life was like for our ancestors. The Hadza people are one of the few hunter-gatherer tribes left, and they number just over one thousand individuals. They are thought to have lived in the same area in the same way for thousands of years; indeed, accounts from the early 20th century describe them living much the same way as they do now.
The Hadza people are very active; the women can travel around 4 miles and men up to 7 miles a day, and this gives us an idea of how much physical activity our ancestors engaged in.
This distance is impressive, but data suggests our ancestors may have travelled even further, for example, there is data showing that Native American bison hunters may have walked up to 24 miles a day when moving camps.
It makes an interesting point to consider: how long would these people have lived on average if they had access to modern medicines as we do now but kept the level of physical activity they engaged in?
Now we are hunting jobs not bisons
Obviously, the life of modern humans is vastly different and the majority of people come nowhere near the activity levels of the Hadza people, let alone the bison hunters. Most of us spend more time chasing people for project deadlines at work and hunting bargains online instead of bison, which is a problem.
As an average, these hunter-gatherers used around 1240 kcal per day through physical activity; modern humans in comparison only use 555 kcal a day. The majority of modern humans do not engage in anywhere near enough physical activity, even though our bodies are designed for the activities our ancestors engaged in, and we have changed very little physically since those days.
Our ancestors burned huge amounts of calories in day-to-day activities due to the hardships of survival in the wilderness, and our bodies have maintained the appetites our ancestors had, even though we use vastly fewer calories than they did. This is a real problem when you consider how easy it is for us to obtain food, and it is quite easy for us to overeat, given the supply of nutrient-rich foods available in modern society.
A lack of physical activity and too many calories quickly adds up to modern humans in industrialized nations commonly suffering from obesity and type 2 diabetes as a result of these lifestyle choices. None of this helps human health, especially with the effects of aging added on, so, in a very real sense, a lack of physical activity can accelerate frailty and aging.
There are a mountain of studies showing that insufficient physical activity leads to age-related conditions, such as osteoporosis. For example, a study of bone density showed significantly higher bone density in the hip joints in primates and hunter-gatherers compared to ancient farmers and modern humans. The weight of scientific evidence strongly supports that adequate physical activity is vital for maintaining health in old age.
Yet more evidence
Obviously, we cannot currently choose not to age, as the technologies to address the aging processes are not yet realized; however, there are numerous studies that show that exercise has an impact on aging and is beneficial even later in life.
Today we have yet another study showing this clear connection; the researchers here investigated if both dancing and fitness training lead to benefits in cognitive function in aged people. The results indicated that both dance and fitness training can induce hippocampal plasticity in the elderly but that only dance training improved balance capabilities.
Taken as a whole with the myriad of other studies linking physical activity and aging, the study here is yet another compelling reason to make exercise a part of your health and longevity strategy.
With a starting price point of being free, depending on if you simply walk or run or pay for a gym or sport, it is without a doubt the most cost-effective health and longevity strategy you can employ now. Exercise is one of the most important measures you can take to reduce the impact of aging while you wait for more robust technologies to arrive.
 Sacha, J., Sacha, M., Soboń, J., Borysiuk, Z., & Feusette, P. (2017). Is It Time to Begin a Public Campaign Concerning Frailty and Pre-frailty? A Review Article. Frontiers in physiology, 8.
 Marlowe, F. (2010). The Hadza: hunter-gatherers of Tanzania (Vol. 3). Univ of California Press.
 Barnard, A. (1998). The foraging spectrum: Diversity in hunter‐gatherer lifeways. American Ethnologist, 25(1), 36-37.
 Eaton, S. B. (2006). The ancestral human diet: what was it and should it be a paradigm for contemporary nutrition?. Proceedings of the Nutrition Society, 65(1), 1-6.
 Ryan, T. M., & Shaw, C. N. (2015). Gracility of the modern Homo sapiens skeleton is the result of decreased biomechanical loading. Proceedings of the National Academy of Sciences, 112(2), 372-377.
 Alves, E. S., Souza, H. S., Rosa, J. P. P., Lira, F. S., Pimentel, G. D., Santos, R. V. T., … & Boscolo, R. A. (2012). Chronic exercise promotes alterations in the neuroendocrine profile of elderly people. Hormone and Metabolic Research, 44(13), 975-979.
 Rehfeld, K., Müller, P., Aye, N., Schmicker, M., Dordevic, M., Kaufmann, J., … & Müller, N. G. (2017). Dancing or fitness sport? The effects of two training programs on hippocampal plasticity and balance abilities in healthy seniors. Frontiers in human neuroscience, 11.