- I'm ready to rumble. - Everyone worries, I think, about death. And so people have always questioned whether this was something that you could actually control.
A lot of people don't realize how much power we actually have over our aging process. - Aging is a subject matter that seems to be shrouded in all kinds of mystery. I don't believe aging is a bad thing.
I believe that we should want to age well inside and out, and it is possible. - What is that lifelong story, that trajectory of what we should be doing for our gender, for our age, for our genetic background that will make the aging process most beautiful for us? - Physical exercise and good health.
Those things act importantly to reduce the likelihoods and eliminate age-related memory loss or at least significantly restrict it. - We evolved to live long in order to be physically active and that physical activity helps us to live longer and stay healthy. - Hey, Big Thinkers, your metabolic health is one of the biggest predictors of how long you live, and how good you feel while living.
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- We know that there is sometimes a disconnect between this concept, what we call lifespan and healthspan. So lifespan is just the time you've been alive between birth and death. And what scientists think healthspan is, is the time you're alive in a more healthy functioning state.
We want to increase quality of life and maintain that over time. And if that produces a longer life, that's an extra bonus, but that's not the ultimate goal. So usually when we think of changes associated with old age, we think of functional changes.
Things like how fast you can run or walk or your ability to go up stairs. Aging is really personified by dysfunction and we see a lot of this in the diseases that tend to arise with aging. - So as people age, they're susceptible to one of two kinds of cognitive declines.
One is Alzheimer's disease, which begins in the 70s, but becomes almost an epidemic when people are in their 90s when almost half the population has Alzheimer's disease. And the other, quite distinct from Alzheimer's disease, is called age-related memory loss. That differs from Alzheimer's disease in the sense that it starts early, starts in midlife, and involves a different part of the brain.
It starts in the dentate gyrus. Alzheimer's disease starts in the entorhinal cortex. - But other things we associate with aging are also changes in body composition.
So often people will maybe gain fat mass around their middle or lose muscle mass. - And one of the real serious most pernicious issues of aging is a problem called sarcopenia. "Sarco" is flesh and "penia" is loss.
So it's flesh loss. As people get older, they tend to lose a lot of strength and power, and that makes basic tasks difficult. And when that happens, people become less active.
When they become less active, they become less fit. And it kind of sets in motion a really disastrous vicious cycle. And so, as we get older, strength training becomes more and more important so that we can avoid those losses of vigor that are really important to maintaining your health and staying strong and staying healthy as we age.
- Lifestyle right now is actually our best ticket in terms of slowing our aging process. And this is really because living systems are adaptive. We adapt to our environment, we adapt to the things we experience.
So you can actually boost things like resilience through different lifestyle behaviors. - And so healthspan is really the key thing. And what physical activity does is it increases your healthspan, and your healthspan therefore increases your lifespan.
So the word exercise comes from the Latin "exercitatio," and it meant to train. I would say that the definition I use of exercise is pretty much the bog standard definition that people in the sort of fitness, exercise science world use. So it's important to make a distinction between physical activity and exercise.
So physical activity is just moving. You do anything. Go shop.
You know, pick up your groceries and take them to your car. That's physical activity. When you sweep the kitchen floor, that's physical activity.
But exercise is discretionary, voluntary physical activity for the sake of health and fitness, right? It's planned. So it can include everything from sports to running on a treadmill, to, you know, going for a walk.
- Every single time you move your body, including when you're running, you are giving your brain what I like to call "a wonderful bubble bath of neurochemicals. " Those neurochemicals include dopamine, serotonin, noradrenaline, endorphins, but it also includes what's called growth factors. Several different growth factors get released with movement, and that is going towards the long-term effects of exercise that can actually help grow and strengthen two key brain areas: One is the hippocampus, critical for long-term memory.
And the second is the prefrontal cortex, critical for your ability to shift and focus attention. The hippocampus is an extraordinary structure because it is one of the only human brain areas that can grow brand new brain cells in adulthood. And what does that mean?
Your memory is better. The other brain area that benefits in terms of growth and strength is the prefrontal cortex. Now, it's not growing new cells.
Some evidence suggests that the outputs of cells in the prefrontal cortex called the axons of those cells perform better, work better with more exercise. - But there's another benefit, right? And the other benefit is that that physical activity is important because when you're physically active, you stress your body.
You produce what's called reactive oxygen species, which cause cellular damage throughout your body. It causes mutations, it causes inflammation. But because that's normal, our bodies turn on all kinds of repair and maintenance mechanisms that counter those.
And as we get older, that repair and maintenance becomes really important because it prevents senescence, it prevents our bodies, from decaying. So when people become physically inactive as they get older, they're no longer turning on those mechanisms that we evolve to use, right, that help us age better, and it makes us more vulnerable to disease and we age faster. - So when we think of stress, we often think stress is evil, but in reality, stress is designed to make us stronger, whether it's emotionally or physically.
Somebody has osteoporosis or osteopenia, right? They have their bone density is becoming compromised with "old age. " Okay, well, why do we recommend working out, in particular with weights?
The idea is that stress is an injury. We're injuring the muscles, we're injuring the bones, right? The bone remodels and becomes more dense.
- Your bones are an endocrine gland. They release a hormone called osteocalcin and it enhances the memory storage in young people, but also enhances memory storage in old people. And one of the reasons that exercise is important is because exercise builds up bone mass.
This is particularly important in women, where bone mass tends to decrease more dramatically than in men, but it's important for everybody. So when you exercise, you increase your bone mass, you increase osteocalcin, and you improve age-related memory loss. - So as we get older, let's not cut back on the physical activity, let's maintain it.
Do some strength, do some endurance. The evidence is incontrovertible. The more we age, the more physical activity is really beneficial.
According to the CDC, only about 20% of Americans get the very minimum levels of exercise that every health organization in the world thinks is the minimum for an adult: which is 150 minutes a week. So 80% of us really struggle and fail to get very basic amounts of exercise. But almost everyone says that they want to get enough exercise.
You know, nobody ever exercised in the Stone Age, right? People were physically active when they had to be, but volitionally going on a 5-mile run in the morning or going to the gym to lift weights whose sole purpose is to be lifted? That's a really strange, weird, modern behavior.
And there are all kinds of instincts that we have not to do it, and we shouldn't make people feel bad; instead, we should help them figure out ways to overcome those instincts. - And so in order for these behaviors in the moment that are less than pleasurable to become manageable, you've got to have perspective and a long-term goal that's worth it. And we call that "Finding your why?
" Is it, "I wanna wear a two-piece instead of a one-piece at spring break because I'm 22? " Or is it, "I want to see my grandchildren graduate from college because I'm 62? " Whatever your motivation is, that's what's critical.
You need to think about what ways health will improve the quality of your life, because I'm gonna tell you right now, that getting healthy usually is dis-pleasurable. - So everybody wonders about what is the best time to work out. And my first answer to that question is always anytime you can fit it in, from morning till night, fit it in.
Physical activity is the most transformative thing that you can do, not only for your body, but for your brain as well. That is the key message. And you don't have to become a marathon runner or triathlete to get these benefits.
- In fact, lots of research shows that physical activities like running actually cause your joints to repair themselves and to stay healthy. But you have to learn how to do it properly. One of the the ways in which we medicalize exercise in the Western world is we think there's a certain amount you should do, right?
We prescribe it, you know? You should take two aspirin, you should get eight hours of sleep, and you should walk 10,000 steps a day. You know, we like that, right?
And there's nothing necessarily wrong with a goal. If you do 8,000 steps, that's fine. If you do 15,000 steps, that's fine.
The important thing is to get, you know, be physically active because some is better than none. There's no magical number. - I like to set smaller goals for myself.
Doable goals. That is the key. Maybe it is a walk on the shore, a walk to the gym, a walk around the museum with friends.
Gardening. People think those things don't count. They all count.
Be more broad in your definition of bringing more movement into your life. - So, is science gonna actually solve death? The important thing is that death is not the ultimate goal in terms of aging research.
What we really want to do is keep people healthy and functioning for as long as possible. And if that results in a longer life expectancy, that ends up just being the added bonus.
