Muscle matters: Dr Brendan Egan at TEDxUCD

Summary

The video script discusses the importance of muscle in energy expenditure and its decline with age, a condition known as sarcopenia. It highlights the impact of modern sedentary lifestyles and medication on muscle health, emphasizing the rise of chronic diseases and muscle wasting in an aging population. The speaker advocates for strength training and bodyweight exercises to combat muscle loss, improve overall health, and enhance the quality of life in older adults, stressing the need for personalized exercise prescriptions similar to medical treatments.

Takeaways

• 💺 Sitting consumes about a calorie per minute, but exercise can increase this energy expenditure by 20 to 30 times.
• 🏋️ Muscles account for 30% of energy expenditure at rest and up to 90% during exercise, making them a key site for burning carbohydrates and fat.
• 🍽️ After eating, approximately 80% of the ingested energy is distributed to muscles, highlighting their importance in energy utilization.
• 🛋️ Prolonged sitting is an independent risk factor for many diseases, even if one exercises regularly.
• 🚶‍♂️ The term 'active couch potato' is used to describe those who exercise but spend most of their day sitting, which can still lead to health issues.
• 💊 Advances in medication have led to an aging population, but this longevity is often accompanied by chronic diseases.
• 👴 By 2050, the number of people over 65 is projected to exceed those under 15 for the first time in human history.
• 🦵 Sarcopenia, the age-related loss of muscle mass and strength, is inevitable and begins after the age of 30, with a loss of 3-8% of muscle mass per decade.
• 🏥 The prevalence of sarcopenia is about 20% in people over 65 and over 50% in those over 85, making it a significant concern for the aging population.
• 🤽‍♂️ Loss of muscle mass and strength increases the risk of falls, fractures, and frailty, impacting independence and overall health.
• 🏋️‍♀️ Resistance training, such as weight lifting, is essential for maintaining and improving muscle mass, unlike aerobic exercises which may not have the same effect.

Q & A

How much energy does the human body expend while sitting?

The human body expends approximately one calorie per minute while sitting.

What happens to the energy expenditure when we exercise?

When we exercise, our energy expenditure can increase by about 20 to 30 times compared to when we are sitting.

What percentage of energy is used by muscles during rest and exercise?

At rest, muscles use about 30% of the body's energy, but during exercise, they contribute up to 90% of the energy.

What is the impact of muscle failure on health?

When muscles begin to fail or develop problems, it can lead to a range of diseases associated with muscle dysfunction.

How does automation affect our physical activity?

Automation in modern life predisposes us to being physically inactive, leading to a majority of our time being spent in a seated position.

What is the term used for the age-related loss of muscle mass and strength?

The term used for the age-related loss of muscle mass and strength is 'sarcopenia'.

What is the prevalence of sarcopenia in the over-65 population in the US?

In the US, the prevalence of sarcopenia in the over-65 population is about 20%.

How does sarcopenia affect balance and the risk of falls?

Sarcopenia, which involves the loss of muscle strength and power, increases the risk of balance issues, falls, and fractures.

What is the impact of sarcopenia on the risk of frailty syndromes and loss of independence?

Sarcopenia is a strong risk factor for frailty syndromes, loss of independence, and general ill health as we age.

How does muscle mass loss affect mortality rates in different age groups?

As muscle mass decreases, particularly in the over-60s, the death rate increases significantly compared to younger individuals with stronger muscles.

What is the principle of specificity in exercise training?

The principle of specificity in exercise training states that the body adapts specifically to the imposed demands, meaning that to improve strength and muscle mass, one needs to engage in weight lifting or similar activities.

What is the principle of progressive overload in exercise training?

The principle of progressive overload in exercise training involves gradually increasing the intensity or volume of exercise to continually challenge the body and promote adaptation and improvement.

How can bodyweight exercises help in maintaining or improving muscle mass?

Bodyweight exercises can help in maintaining or improving muscle mass by providing resistance against the body's own weight, which can be effective in both young and older adults.

What is the message conveyed about the importance of exercise in relation to muscle health?

The message conveyed is that exercise should be prescribed like medicine, tailored to the individual and their condition, emphasizing the need for strength training and avoiding inactivity to maintain muscle health.

Outlines

00:00

💺 Inactivity and Muscle Function

This paragraph discusses the energy expenditure while sitting and how it contrasts with the energy used during exercise. It highlights the muscle's role in energy consumption, both at rest and during physical activity. The script points out the modern lifestyle's tendency towards automation, leading to prolonged periods of inactivity, which is a significant risk factor for various diseases. It also touches on the paradox of inactivity leading to muscle atrophy, despite the common association of a sedentary lifestyle with obesity. The paragraph concludes with a discussion on the aging population and the prevalence of chronic diseases, introducing sarcopenia as a significant concern in older adults.

05:02

🏋️‍♂️ The Impact of Muscle Loss on Health and Aging

The second paragraph delves into the consequences of muscle loss, particularly sarcopenia, which is characterized by the age-related decline in muscle mass and strength. It emphasizes the importance of muscle strength for maintaining balance and independence, and how muscle loss can lead to frailty and increased risk of falls and fractures. The script also addresses the issue of disease-related malnutrition in Ireland, highlighting its significant economic impact. Furthermore, it discusses the correlation between strength and longevity, indicating that maintaining muscle mass can improve life expectancy. The paragraph also explores the rapid muscle loss that can occur due to inactivity or bed rest, underscoring the importance of regular physical activity.

10:04

🏋️‍♀️ Combating Muscle Loss Through Exercise

The final paragraph focuses on the potential of exercise to combat muscle loss, even in the elderly. It presents evidence of significant muscle mass and strength improvements in individuals over 85 years old through targeted training. The script advocates for the use of bodyweight exercises as an accessible and effective way to increase muscle mass and strength, citing studies that show positive results in both young and older adults. It also emphasizes the importance of exercises that mimic daily activities to improve functional capacity and maintain independence in older age. The paragraph concludes with a call to action, urging the prescription of exercise as a critical component of health care, tailored to individual needs and conditions.

Keywords

💡Calorie expenditure

Calorie expenditure refers to the amount of energy used by the body, typically measured in calories. In the context of the video, it is mentioned that sitting expends about a calorie per minute, whereas exercise can increase this rate significantly. This concept is crucial as it highlights the importance of physical activity in maintaining energy balance and overall health.

💡Muscle atrophy

Muscle atrophy is the process of muscle tissue wasting away, leading to a decrease in muscle mass and strength. The video emphasizes that muscle is a significant contributor to energy expenditure and that its atrophy can lead to various health issues. The script mentions that muscle mass decreases by 3 to 8% per decade after the age of 30, illustrating the natural aging process and its impact on muscle health.

💡Sarcopenia

Sarcopenia is defined as age-related muscle loss, characterized by a decrease in muscle mass and strength. The term originates from Greek, meaning 'poverty of flesh' and 'poverty of strength.' The video discusses sarcopenia as a prevalent condition among the elderly, affecting about 20% of those over 65 and over 50% of those over 85, emphasizing its role in increased frailty and health risks.

💡Inactivity

Inactivity, as discussed in the video, refers to a sedentary lifestyle where physical activity is minimal. It is highlighted as an independent risk factor for many diseases and is associated with muscle atrophy and increased health issues. The script mentions that even with exercise, prolonged sitting can negate its benefits, underscoring the need for continuous movement throughout the day.

💡Exercise

Exercise is any physical activity that increases heart rate and uses muscles, improving overall health and fitness. The video script emphasizes the importance of exercise in increasing energy expenditure, maintaining muscle mass, and preventing diseases. It also discusses the need for specific types of exercise, such as strength training, to counteract muscle atrophy and sarcopenia.

💡Strength training

Strength training involves exercises that increase muscle strength and size by causing muscle fibers to contract against resistance. The video highlights the benefits of strength training in maintaining and improving muscle mass, particularly in older adults. It contrasts this with aerobic exercise, suggesting that a combination of both is beneficial for overall health.

💡Progressive overload

Progressive overload is a principle in exercise training that involves gradually increasing the stress placed upon the body during exercise to induce adaptation and improvement. The video uses the example of a wrestler carrying a growing bull to illustrate this concept, emphasizing that continuous challenge is necessary for muscle growth and health.

💡Bodyweight exercises

Bodyweight exercises are physical exercises that use the weight of one's own body as resistance. The video script discusses studies showing that these exercises can improve muscle mass and strength, particularly in older adults, without the need for expensive equipment. This type of exercise is also relevant to everyday activities, making it accessible and practical.

💡Frailty syndromes

Frailty syndromes are conditions characterized by a decline in physical resilience and strength, often associated with aging. The video connects frailty syndromes with the loss of muscle mass and strength, highlighting the increased risk of falls and fractures. It suggests that maintaining muscle mass through exercise can help prevent these syndromes.

💡Disease-related malnutrition

Disease-related malnutrition refers to a condition where malnutrition is a consequence of a disease or its treatment. The video mentions that in Ireland, about 140,000 people suffer from this condition, which is associated with muscle wasting and sarcopenia. It emphasizes the economic and health impact of this issue, illustrating the broader consequences of muscle health on society.

Highlights

Sitting expends about a calorie per minute, but exercise can increase this energy expenditure by 20 to 30 times.

Muscles contribute about 30% of energy expenditure at rest and 90% during exercise, making them a major site for burning carbohydrates and fat.

Muscle failure can lead to a range of diseases, highlighting the importance of muscle health.

Automation and a sedentary lifestyle are major factors contributing to physical inactivity and associated health risks.

Even with exercise, spending most of the day sitting can still be detrimental to health, labeling such individuals as 'active couch potatoes'.

Muscles of inactive individuals, like those depicted as 'couch potatoes', actually shrink over time, contrary to the common misconception of inactivity leading to increased size.

The aging population and advancements in medication are leading to longer lifespans but also an increase in chronic diseases.

By 2050, the number of people over 65 is projected to exceed those under 15 for the first time in human history.

Sarcopenia, the age-related loss of muscle mass and strength, is an inescapable fact affecting individuals after the age of 30.

Every decade after the age of 30, individuals lose between 3 to 8% of their muscle mass.

Sarcopenia is prevalent, with about 20% of people over 65 and over 50% of those over 85 affected in the US.

Loss of muscle mass and strength is a strong risk factor for frailty, loss of independence, and general ill health in older adults.

Disease-related malnutrition is a significant issue in Ireland, affecting 140,000 people and costing 1.5 billion euros.

Strength is crucial as it is associated with a lower death rate; the stronger individuals have half the death rate of the weakest.

Sarcopenia is related to various diseases, and muscle wasting is a common factor in these conditions.

Reduced activity, such as making individuals take fewer steps, can lead to a rapid loss of muscle mass, even in young healthy individuals.

Elderly individuals can still make significant improvements in muscle mass and strength through targeted exercise training.

Bodyweight exercises are an effective way to improve muscle mass and strength, and can be done without expensive equipment.

Maintaining muscle mass through exercise can delay the aging process and improve overall health and functional capacity in older adults.

Exercise should be prescribed like medicine, tailored to the individual and their condition, to effectively combat age-related muscle wasting.

Transcripts

as you sit there in your chair you

expend in a rough amount of energy

somewhere around a calorie per minute

when we exercise we can increase this by

about 20 or 30 fold as you sit there

your muscle country's about 30 percent

of your energy during exercise a

contributor of 90 percent of your energy

so it becomes the major site where we

burn carbohydrate and fat and when we

eat a meal about 80 percent of the

energy that's ingested in that meal is

distributed to the muscle in other words

when muscle begins to fail or when we

develop problems with a muscle is it's

not surprising then that we develop a

range of diseases associated with that

there's two things that have happened in

modern science that have unintended

consequences in terms of the way that

muscle functions the first is automation

so in modern life now we're predisposed

to being physically inactive we spend a

large amount of our time in a sitting

position so even if we do or half-hour

of purposeful exercise first thing in

the morning we spend it about 90 percent

of the next 15 and a half hours of

waking we spend our time in a seated

position

so one of the problems with sitting is

that it's an independent risk factor for

a majority of diseases in other words

even if you do exercise first thing in

the morning or last thing at night or

whenever you exercise you're in the day

if you do in a single bout and you spend

the rest of your day sitting you might

be called what's classified as an act

active couch potato

so potatoes are much used for muscles

and so if you look at someone like this

and we tend to associate inactivity and

inappropriate diet with that with the

increase in size in actual fact the

muscles of individuals such as this guy

on the couch are actually getting

smaller and smaller and working less and

less the second major thing that modern

science has delivered us is medication

and as a result we're living longer and

longer so we have a worldwide aging or

grain population and if you look at the

yellow segment on those pie charts

that represents the numbers of people

who are over 65 so a current projections

sometime after the year 2050 the numbers

of people who are greater than 65 years

of age will exceed the numbers of people

who are less than 15 years of age for

the first time in human history however

with the aging and with extended

lifespans

due to this improvements in our

medication unfortunately that's

associated with chronic diseases so in

data from the US adults aged over 65

years the current numbers would suggest

that ninety two point two percent of

those individuals have one or more

chronic diseases so although we're

living longer we might not necessarily

be living healthier in this case chronic

diseases were defined as the usual ones

we tend to hear about hypertension

coronary heart disease stroke cancer and

so forth but as one disease that's not

mentioned here that I want to talk a bit

more about today in that sarcopenia so

sarcopenia is defined as the edge

related wasting of muscle and the in the

word comes from greek which means a

poverty of flesh but it also means a

poverty of strength so we lose muscle

mass and we lose strength as we age and

there's no way it's inescapable it's a

fact that happens after about the age of

30 we lose it 3 to 8% of our muscle

every decade keep that number in mind

because I'm going to come back to it so

every decade we lose somewhere between 3

and 8 percent of our muscle on the right

hand side and in the second figure there

you see the appearance of the time

muscle of an individual cross section of

their tie and what you can see there is

at an elderly individual they've lost a

large proportion of the muscle mass so

the white color there indicates adipose

tissue or fat so muscle is shrunk

we've lost muscle as we age beneath that

is a 74 year old athlete who has trained

their whole life and it's managed

maintained their muscle mass and despite

what I said was the inescapable fact we

would lose muscle throughout our life so

you might wonder what is the prevalence

of sarcopenia is it just some disease

that this guy is really interested

you know it's not really that relevant

well at the moment in over 65s it's

about twenty verse this is data from the

US it's about twenty percent prevalence

in people over the age of 85 greater

than half of the individuals have

sarcopenia now when you lose strength

and you lose power in your muscles you

lose these are these are things that are

greatly associated with balance if you

lose your capacity to balance

you're more predisposed to Falls and

fractures so this loss of muscle mass is

a is a strong risk factor for frailty

syndromes for loss of Independence and

for general ill health as we age we

don't have any figures for Ireland but

what we do know in Ireland is that this

there's another pair to this story which

is disease related malnutrition and this

might surprise you but in Ireland at any

one time there's 140,000 people who are

suffering from disease related

malnutrition that cost about indirect

costs about 1.5 billion euro to the

Exchequer and you might think well how

much does that mean you know is what

kind of disease is this again that's

more than the direct cost of obesity so

this is a this is a an invisible type of

disease disease related malnutrition

very strongly associated with

age-related muscle wasting so why is

strength important

I mentioned the incidence of frailty and

loss of Independence if we look at

individuals who are either over 60 or

under 60 and we look at their strength

so their whole body strikes three colors

here represent weak individuals the

average individuals to strong

individuals if you look at the two red

bars what you see there is that as we

age so the over-60s day over four and

four times elevated death rate compared

to the under 60s so that makes sense if

we're a little older we're more likely

to die however on the right-hand side if

you compare the green to the red the

stronger that you are so the strongest

heart of the population have half the

death rate of those who are weakest in

other words if you preserve your muscle

mass you have a greater chance of living

that little bit longer now

why would that effect be so obvious and

why would it be of relevance to

something like cancer so are there are

other diseases that that sarcopenia or

muscle-wasting relate to and there are

so all of these diseases listed on this

slide and cone coincide with muscle

wasting so in each one of those when the

disease manifests itself it's also

associated with the loss of muscle mass

and therefore a loss of Independence

what I want to focus on is a

mobilization and bed rest so if you take

young healthy males in the twenties

student aged student population and

you've probably heard of this ten

thousand steps that you need to do in

any given day in order to be to be

healthy if you take people who were

making those ten thousand steps and you

reduce their activity by making them

take elevators and make them take

escalators pushing around in wheelchairs

making them sit a lot more we reduce

their number of steps to two thousand

they lose about five percent of the

muscle mass in the space of 14 days so I

said that usually we lose about three to

eight percent per decade over the age of

thirty these guys lose 5% of their

muscle mass within 14 days if an elderly

person over the age of 70 is bedridden

for ten days they lose 10% to the most

of us

in other words depending on the

situation in as little as two weeks you

can lose the equivalent muscle mass of

what would take a decade to lose so we

want to avoid these things we want to

avoid mobilization we want to stay

active we want to avoid bed rest where

possible so how should we do this and

typically what we're told is that we

need to get out and walk more we need to

do half an hour of activity accumulated

on five different days of the week well

I'm going to tell you that that's

probably not enough so the principle of

specificity in terms of exercise

training is that the body adapts

specifically to the the imposed demands

so if we want to get bigger if we want

to improve our strength and improve our

muscles we have to lift weight going out

for a walk isn't going to make you

stronger and in fact there's some

evidence to say that like people who are

lifelong in

aerobic or querida sports to losing

muscle mass compared to those

individuals who do strength training

the other interesting thing is that when

it comes to diseases like diabetes and

obesity the most recent evidence would

suggest that it's combined endurance and

robic exercise that works you shouldn't

just be doing one or the other there

should be a combination within there a

second principle in an exercise training

is the principle of progressive overload

and this is Milo the wrestler

two and a half thousand years ago famous

Greek wrestler and the story goes that

in order to develop his strength as he

as he grew he used to carry a bull a

calf around from a young age so he

carried it every day and as the bull got

bigger he got stronger I don't know if

this is true but the point is that each

day he pushed himself a little bit

harder and his body adapted accordingly

and that's what an important principle

of the way we exercise so then the

question is if an adult is old around

this case they're over there over 85

years of age if we exercise train them

can they actually make improvements so

on the left hand side what you're seeing

there it's pre-imposed too much you're

looking at the cross-section area and in

this particular individual that person's

muscle in the quad again they're in

their time muscle has increased by about

44% on the right hand side you're

looking at their improvement in strength

it's improved by about 50%

that was after 12 weeks of training that

focused on anti-partisan muscles in 85

year old individuals so in this case the

muscle wasting could be reversed in

other words we've reversed the aging

process so how should we exercise then

does it have to have to go to a gym do

we have to do to have to invest in

expensive equipment something we're

excited about aucd at the moment is

using bodyweight exercises so these are

exercises that you use your own

bodyweight in space to provide a

resistance against your against your

against your muscles so I'll give you

two little studies that we've done right

now

we took young college age males again

obese and overweight and we trained them

for six weeks three days a week half an

hour each day and all they did were

these body which type exercises no

equipment

after six weeks we saw about a three

percent improvement in muscle mass

particularly in the legs and we have

that holy grail that lasts a small bit

of fat as well there were young

individuals in older adults starting at

the age of 55 would have a mean age of

about 63 we see the same thing after 12

weeks body weight on the exercises three

times a week we see about a three

percent improvement in in their muscle

mass so improving muscle mass is one

thing but these exercises are very

similar to things that we do and not in

everyday activities so we lift things

above our head we get up off the ground

we get up out of chairs so these are

what we call activities of daily living

and one of the major predictors of loss

of Independence is when an older adult

can no longer do these activities of

daily living so we're excited now to

begin to look at these bodyweight

exercises and how they might improve the

overall health and function functional

capacity of older adults so I suppose

the last thing I'll say is that in the

case of sarcopenia or muscle wasting you

don't just wake up one day and have this

situation it's a continuum progresses

over time and so I was talking about

those bodyweight exercises being able to

increase muscle mass but if we can just

delay the aging process so if we if we

just maintain muscle mass rather than

actually having to improve it in that in

itself would have benefits to their

overall health so my simple message is

this

we need to prescribe exercise like we

prescribed medicine so we shouldn't just

give everyone to say a medicine we

should treat the individual and we

should treat the condition so going out

and doing 30 minutes of walking every

day might not call it when it comes to

people who have age related muscle

wasting so in other words what I'd say

is usage or lose it because muscle

matters and only the strong survive

thank you

you

you