Harvard professor debunks the biggest exercise myths | Daniel Lieberman

Big Think

21 Aug 202204:34

Summary

TLDRThis video challenges common myths about exercise, drawing insights from evolution and anthropology. It emphasizes that our ancestors were active hunter-gatherers, walking extraordinary distances daily. Contrary to popular belief, activities like running don't necessarily damage knees but can promote joint repair. As we age, maintaining physical activity and strength training becomes crucial to avoid sarcopenia (muscle loss) and preserve health span. The video urges viewers to embrace exercise as a natural part of aging, dispelling the notion that reduced activity is normal. With compelling evidence, it advocates for regular physical activity to enhance overall well-being and longevity.

Takeaways

🏃‍♀️ Walking is the most fundamental form of human physical activity that we evolved for, with hunter-gatherers taking around 10-15,000 steps per day.
⚠️ Many common myths about exercise persist, such as the belief that our ancestors were incredibly strong, that there's a trade-off between speed and strength, and that physical inactivity is normal with aging.
😓 Only 20% of Americans meet the minimum recommended exercise guidelines of 150 minutes per week, despite most people wanting to exercise more.
🏃 Contrary to popular belief, running does not necessarily destroy your knees, and can actually help maintain joint health if done properly.
🏋️‍♀️ Strength training becomes increasingly important as we age to avoid sarcopenia (muscle loss) and maintain vigor and health.
🏃‍♂️ The idea of running long distances multiple times a week on pavement is a modern Western practice, unlike ancestral running patterns.
🧠 Physical activity increases not just lifespan but, more importantly, healthspan – the duration of healthy living.
🔄 Inactivity can lead to a vicious cycle of reduced fitness, strength, and further inactivity as we age.
💪 Hunter-gatherers maintained physical activity and strength into older age due to their active lifestyles, unlike the decline seen in modern societies.
🚶‍♀️ Rather than reducing physical activity as we get older, maintaining exercise and strength training is crucial for preserving health and avoiding age-related decline.

Q & A

What is the fundamental form of human physical activity that we evolved to do?
-According to the script, the most fundamental and basic form of human physical activity that we evolved to do is walking. It mentions that walking is the one physical activity that humans evolved to do.
How many steps do hunter-gatherers typically take in a day compared to the average American?
-The script states that the average hunter-gatherer takes 10,000 to 15,000 steps a day, while the average American before the pandemic was taking only around 4,700 steps a day.
What percentage of Americans get the minimum recommended amount of exercise?
-According to the script, only about 20% of Americans get the very minimum levels of exercise that every health organization in the world recommends for adults, which is 150 minutes per week. This means that 80% of Americans struggle to get even the basic recommended amount of exercise.
Is the myth that running will destroy your knees supported by scientific evidence?
-No, the script states that there are numerous randomized, controlled studies (the gold standard for research) which show that people who run more are not more likely to develop arthritis. In fact, research shows that physical activities like running can actually cause your joints to repair themselves and stay healthy.
Why does the script suggest that modern running habits may contribute to injuries?
-The script suggests that some running injuries may be caused because we don't learn how to run properly anymore. It states that running is a skill that needs to be learned, like swimming or throwing. Additionally, it notes that hunter-gatherers would likely run only once a week or so, rather than the modern habit of running long distances on pavement multiple times per week, which is described as a "weird, strange Western thing."
What is 'sarcopenia' and why is it a concerning issue as people age?
-Sarcopenia is the loss of flesh or muscle mass as people get older. The script states that this is a serious, pernicious issue of aging in the Western world, as people tend to lose a lot of strength and power, making basic tasks difficult. This can lead to a disastrous, vicious cycle of becoming less active, less fit, and losing more strength.
Why does the script suggest that physical activity becomes more important as we age?
-The script suggests that as we get older, strength training and physical activity become more important, not less, in order to avoid the losses of vigor and strength associated with sarcopenia. It states that the evidence is incontrovertible that physical activity is beneficial for preserving health as we age.
What is the difference between 'lifespan' and 'healthspan' mentioned in the script?
-The script distinguishes between lifespan, which is how long someone lives, and healthspan, which is how long someone remains healthy. It states that before modern medicine, healthspan was the key factor that determined lifespan, as physical activity increases healthspan, which in turn increases lifespan.
What advice does the script give regarding physical activity levels as people get older?
-The script advises against cutting back on physical activity as we get older. Instead, it recommends maintaining physical activity levels, including strength training and endurance activities, in order to preserve health and avoid the detrimental effects of aging.
What is the overall message the script is trying to convey about exercise and physical activity?
-The overall message of the script is to debunk common myths about exercise and physical activity using an evolutionary and anthropological lens. It emphasizes the importance of regular physical activity, particularly walking and strength training, for maintaining health and functional abilities throughout the lifespan, especially as we age.

Outlines

00:00

🏃‍♀️ Debunking Common Myths About Exercise

The paragraph discusses various myths surrounding exercise, such as the belief that our ancestors were incredibly strong, the trade-off between speed and strength, the notion that it's normal to be less physically active with age, and the idea of a perfect type and amount of exercise. The author aims to debunk these myths using the lenses of evolution and anthropology in a book. Walking is highlighted as the most fundamental form of human physical activity, with hunter-gatherers taking 10,000 to 15,000 steps daily, compared to the average American's 4,700 steps before the pandemic. Only 20% of Americans meet the minimum recommended exercise levels, despite most people expressing a desire for sufficient exercise.

Mindmap

Keywords

💡Myths

Myths refer to widely held beliefs or ideas that are false or unproven. The speaker suggests that there are many misconceptions surrounding exercise that need to be debunked. For example, the myth that our ancestors were incredibly strong or that it's normal to be less physically active as you age.

💡Evolution

Evolution refers to the gradual process by which species change over time through adaptation and natural selection. The speaker uses an evolutionary lens to understand human physical activity, such as our ancestors' need to walk long distances as hunter-gatherers. This provides insights into the types of exercise our bodies evolved for.

💡Anthropology

Anthropology is the study of human societies and cultures and their development. The speaker draws from anthropological research on hunter-gatherer societies to gain insights into how much physical activity our ancestors engaged in and what types, like walking long distances daily.

💡Walking

The speaker identifies walking as the most fundamental form of human physical activity that our bodies evolved for. Our hunter-gatherer ancestors walked 10-15,000 steps per day on average, much higher than the modern American average of around 4,700 steps before the pandemic.

💡Exercise guidelines

Health organizations recommend at least 150 minutes of exercise per week as the minimum for adults. However, the speaker notes that only 20% of Americans meet this very basic guideline, indicating that most struggle to get sufficient exercise despite wanting to.

💡Running

The speaker debunks the myth that running will destroy your knees. Multiple studies show that runners are not more likely to develop arthritis, and running can actually help repair and maintain healthy joints. However, proper running form and building up strength gradually are important to avoid injuries.

💡Sarcopenia

Sarcopenia refers to the loss of muscle mass and strength that often occurs with aging in Western societies. The speaker contrasts this with hunter-gatherer societies where physical activity is maintained as people age, helping them avoid sarcopenia and maintain strength longer.

💡Strength training

The speaker emphasizes the increasing importance of strength training as we age to avoid losses of vigor and maintain health. Regular strength training can help counteract the muscle and strength losses (sarcopenia) that are common in older adults in Western societies.

💡Healthspan

Healthspan refers to the length of time a person remains healthy, in contrast to lifespan which is total years lived. The speaker argues that physical activity increases one's healthspan, which in turn increases lifespan by allowing people to live more healthy years.

💡Incontrovertible evidence

The speaker states that there is overwhelming, indisputable evidence showing the benefits of maintaining physical activity as we age, contrary to the myth that being less active is normal. Studies have found exercise to be increasingly important, not less, for preserving health in older adults.

Highlights

One myth is that our ancestors were really incredibly strong.

That there's a trade-off between speed and strength.

That it's normal to be less physically active as you get older.

That there's a perfect type of exercise, perfect amount of exercise.

If there's any one physical activity that humans evolved to do, it's to walk.

The average sort of hunter-gatherer will take 10, 15,000 steps a day.

The average American before the pandemic was taking something like 4,700 and something steps a day.

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.

We live in a world where we no longer have to be physically active. We now, in a very strange way, have to choose to be physically active.

One of the biggest myths about running is that it'll destroy your knees.

There's tons and tons of studies, more than a dozen, randomized, controlled-perspective, gold standard studies, which show that people who run more are not more likely to get arthritis.

Physical activities like running actually cause your joints to repair themselves, and to stay healthy.

Running is a skill, like swimming or throwing or, you know, all kinds of other things that we do.

The idea that you go running five, six times a week, for long distances on pavement, etc., these are all kinda weird, strange Western things.

The most pernicious, the most serious, the most problematic, the most concerning way in which we think about exercise in the Western world, is that as people get older, it's kind of normal to be less physically active.

As people get older in the West, 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.

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.

What physical activity does, is it increases your healthspan, and your healthspan therefore increases your lifespan.

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. There's tons of data which show that as we get older, the more physical activity is really beneficial.