23 and 1/2 hours: What is the single best thing we can do for our health?

Summary

In '23 and a Half Hours,' Dr. Mike Evans emphasizes the profound health benefits of exercise, primarily walking. He presents evidence showing how regular physical activity can significantly reduce risks of various health issues, including arthritis pain, dementia, diabetes, and depression. Evans suggests that dedicating just 30 minutes a day to exercise can yield substantial health returns, advocating for a lifestyle that limits sedentary time to encourage a more active, healthier life.

Takeaways

• 😀 Dr. Mike Evans emphasizes the importance of preventive medicine, which includes various factors like diet, social connections, and lifestyle habits.
• 🔍 He seeks to identify the most impactful health intervention with the highest return on investment for overall health.
• 🏃‍♂️ The intervention identified is exercise, particularly walking, which has a broad positive impact on health across multiple conditions.
• 📉 Exercise has been shown to significantly reduce pain and disability in knee arthritis, dementia risk, diabetes progression, hip fracture risk, anxiety, and depression.
• 📊 A long-term study of Harvard Alumni revealed that exercise reduced the risk of death by 23% compared to no exercise.
• 🚶‍♀️ Exercise is considered the top treatment for fatigue and consistently improves quality of life.
• 🕒 The concept of '23 and a Half Hours' suggests dedicating at least 30 minutes a day to physical activity for optimal health benefits.
• 📈 Research by Stephen Blair indicates that low fitness is the strongest predictor of death, highlighting the importance of regular physical activity.
• 🔄 The benefits of exercise can be achieved with both high-intensity and low-intensity activities, with the key being consistency and personalization to one's lifestyle.
• 🐾 The presence of a pet, such as a dog, can be a strong motivator for regular walks and achieving recommended activity levels.
• 🛋️ A study by Leonard Veerman quantified the negative health effects of prolonged sitting, with significant reductions in life expectancy associated with excessive TV watching.

Q & A

What is the title of Dr. Mike Evans' visual lecture?

The title of the lecture is '23 and a Half Hours'.

What is the main focus of Dr. Mike Evans' lecture?

The main focus of the lecture is on the impact of exercise, particularly walking, on various health issues and its role in preventive medicine.

What health benefits does Dr. Evans mention as a result of the intervention in patients with knee arthritis?

In patients with knee arthritis, the intervention reduced their rates of pain and disability by 47 percent.

How does the intervention affect the risk of dementia and Alzheimer's in older patients?

The intervention reduced the progression to dementia and Alzheimer's by around 50 percent in older patients.

What impact does the intervention have on patients at high risk of diabetes?

For patients at high risk of diabetes, the intervention, combined with other lifestyle interventions, reduced the progression to frank diabetes by 58 percent.

How does the intervention affect the risk of hip fracture in post-menopausal women?

Post-menopausal women who had four hours a week of the treatment had a 41 percent reduction in the risk of hip fracture.

What percentage reduction in anxiety was observed in a meta-analysis of the intervention?

The intervention reduced anxiety by 48 percent in a large meta-analysis.

What was the percentage of patients suffering from depression that were relieved with low dose intervention, and what happens when the dose is increased?

Thirty percent of patients suffering from depression were relieved with low dose intervention, and this increased to 47 percent when the dose was increased.

What was the observed reduction in risk of death for those who had the intervention compared to those who did not, according to a study following over 10,000 Harvard Alumni for over 12 years?

Those who had the intervention had a 23 percent lower risk of death than those who did not receive the treatment.

What is the number one treatment for fatigue according to Dr. Evans' lecture?

According to the lecture, exercise, particularly walking, is the number one treatment for fatigue.

What does Dr. Evans suggest as the best way to spend half an hour of your typical day for health benefits?

Dr. Evans suggests that the best thing for your health is to spend half an hour being active, which can be achieved through activities like walking.

What is the Attributable Fractions and how is it used in the study mentioned by Dr. Evans?

Attributable Fractions is an estimate of the number of deaths in a population that would have been avoided if a specific risk factor had been erased. In the study mentioned, it was used to compare the impact of different risk factors on mortality.

What was the finding of the study conducted by a large gas company in Japan regarding the relationship between walking to work and high blood pressure?

The study found that for every increase of 10 minutes in the walk to work, there was a 12 percent reduction in the likelihood of getting high blood pressure.

What was the outcome of the comparison between exercise and stents in a study by German researcher Rainer Hambrecht involving cardiac patients?

After one year, 88 percent of the exercisers were event-free compared to 70 percent of the people who received a stent, indicating that exercise made a bigger difference in health outcomes.

What is the term used to describe the negative health effects associated with prolonged sitting, and what did Leonard Veerman's study find regarding its impact on lifespan?

The term used is 'sitting disease'. Veerman's study found that those who watched no TV could expect to live about five years more than those who watched an average of six hours a day.

What personal challenge does Dr. Evans pose to the audience at the end of his lecture?

Dr. Evans challenges the audience to limit their sitting and sleeping to just 23 and a half hours a day, implying the importance of incorporating more physical activity into their daily routines.

Outlines

00:00

🏃‍♂️ The Power of Exercise in Preventive Medicine

Dr. Mike Evans introduces his lecture '23 and a Half Hours,' emphasizing the significance of preventive medicine in various aspects such as cancer screening, diet, and social connections. He explores the concept of the most impactful health intervention, revealing it to be exercise, particularly walking. The summary highlights the benefits of exercise for conditions like knee arthritis, dementia, diabetes, and mental health, as well as its overall enhancement of quality of life. Dr. Evans suggests that dedicating at least half an hour a day to activity can yield substantial health benefits.

05:00

🚶‍♀️ Exercise as a Dose: Balancing Activity and Sedentary Time

This paragraph delves into the specifics of how much and what type of exercise is beneficial. It discusses the transition from inactivity to any level of activity and the incremental benefits thereafter. The summary points out that even light exercise can significantly reduce the risk of heart disease and that higher intensity exercise can be equivalent to longer periods of lower intensity. Personal habits and cues are suggested as strategies to integrate exercise into daily routines. The paragraph also presents evidence from various studies, including the positive effects of walking to work on reducing high blood pressure and the comparison of exercise to medical procedures like stents in cardiac patients. It concludes with a challenge to limit sedentary behaviors to make room for more active living.

Keywords

💡Preventive Medicine

Preventive medicine refers to measures taken to prevent the occurrence of diseases or maintain health. In the context of the video, it encompasses a range of practices from cancer screening to dietary habits and maintaining a social network. The video emphasizes the significance of preventive medicine as the first step in addressing health issues, rather than solely relying on treatments after diseases manifest.

💡Return on Investment

Return on investment (ROI) is a financial term used to measure the benefit an investor receives in relation to their investment. In the video, Dr. Mike Evans uses this term metaphorically to discuss the effectiveness of different health interventions, particularly emphasizing the high ROI of exercise in improving health outcomes and reducing the risk of various diseases.

💡Knee Arthritis

Knee arthritis is a medical condition characterized by the inflammation and degeneration of the knee joint. The script mentions that exercise, specifically one hour of treatment three times a week, significantly reduced pain and disability in patients with knee arthritis by 47 percent, illustrating the therapeutic benefits of physical activity for this condition.

💡Dementia and Alzheimer's

Dementia and Alzheimer's are cognitive disorders that affect memory and cognitive function. The video script highlights research showing that exercise can reduce the progression to dementia and Alzheimer's by around 50 percent in older patients, underscoring the neuroprotective effects of physical activity.

💡Diabetes

Diabetes is a chronic condition characterized by high blood sugar levels due to insufficient insulin production or function. The script notes that exercise, combined with other lifestyle interventions, reduced the progression to type 2 diabetes by 58 percent in high-risk patients, demonstrating the role of physical activity in disease prevention.

💡Hip Fracture

A hip fracture is a break in the upper part of the thigh bone, which can occur due to osteoporosis or falls. The video mentions that post-menopausal women who engaged in four hours a week of exercise had a 41 percent reduction in the risk of hip fracture, indicating the protective effect of physical activity against bone-related injuries.

💡Anxiety and Depression

Anxiety and depression are mental health conditions that can affect mood, thoughts, and behavior. The script provides evidence that exercise reduced anxiety by 48 percent and relieved depression in 30 to 47 percent of patients, depending on the dosage of exercise, highlighting the mental health benefits of physical activity.

💡Quality of Life

Quality of life refers to an individual's overall well-being and satisfaction with various aspects of their life. The video emphasizes that exercise has been shown to improve quality of life, which includes physical, emotional, and social well-being, and is a comprehensive outcome that encapsulates the benefits discussed.

💡Exercise

Exercise is any physical activity that helps improve health and fitness. In the script, Dr. Mike Evans identifies exercise, particularly walking, as the key intervention for various health benefits. The video script discusses the dosage of exercise in terms of duration, frequency, and intensity, and how it can be incorporated into daily routines.

💡Cardio-Respiratory Fitness

Cardio-respiratory fitness refers to the ability of the circulatory and respiratory systems to supply oxygen during sustained physical activity. The video script cites research indicating that low fitness is the strongest predictor of death, highlighting the importance of maintaining good cardio-respiratory health through regular exercise.

💡Sitting Disease

The term 'sitting disease' is used in the video to describe the negative health effects associated with prolonged periods of sitting or inactivity. The script references a study that quantified the impact of excessive TV watching on life expectancy, illustrating the risks associated with a sedentary lifestyle.

Highlights

Dr. Mike Evans introduces the concept of '23 and a Half Hours', emphasizing the importance of preventive medicine.

Exercise, particularly walking, is identified as the most impactful intervention for various health issues.

Exercise reduces pain and disability in knee arthritis patients by 47% with just one hour of treatment three times a week.

In older patients, exercise can reduce the progression to dementia and Alzheimer's by around 50%.

For high-risk diabetes patients, exercise combined with lifestyle changes can reduce the progression to diabetes by 58%.

Post-menopausal women who exercise four hours a week have a 41% reduction in hip fracture risk.

Exercise reduces anxiety by 48% and depression symptoms by 30-47% depending on dosage.

A 23% lower risk of death is associated with the exercise intervention in a 12-year study of over 10,000 Harvard Alumni.

Exercise is the top treatment for fatigue and significantly improves quality of life.

Stephen Blair's research indicates that low fitness is the strongest predictor of death, more so than other risk factors.

Obesity combined with inactivity is detrimental, but exercise can mitigate the negative health effects of obesity.

The optimal exercise dose is more activity, but the rate of return declines after 20-30 minutes a day.

Even a small increase in activity, such as a 10-minute walk, can significantly reduce the risk of heart disease.

Higher intensity exercise can be equivalent to less time spent on lower intensity activities.

Dog walking is a natural motivator for achieving the recommended 150 minutes of weekly exercise.

A longer walk to work is associated with a reduced risk of high blood pressure.

Exercise can be more effective than high-tech medical interventions like stents for cardiac patients.

Sedentary behavior, such as watching TV for extended periods, can lead to a reduced life expectancy.

Dr. Evans challenges the audience to limit their sitting and sleeping to just 23 and a half hours a day.

Transcripts

[sound of marker on white board]

DR. MIKE EVANS: Hi, I’m Dr. Mike Evans and welcome to

this visual lecture I’m calling, "23 and a Half Hours".

So I have a big interest in preventive medicine, you know,

which can mean a lot of things from,

you know, cancer screening, to eating more fibre,

to having a good social network and I -- I mean that

in the old sense of the word.

Weighing less, drinking less, smoking less,

controlling your blood pressure, cholesterol,

and so on and so forth.

So all these things are incredibly important and

I wouldn’t want you to minimize your efforts in

any one category.

But I -- I want to know what comes first.

What has the biggest impact, what has

the biggest return on investment?

[sound of cash register ringing]

What makes the biggest difference to your health?

So I did my research, and I found an answer,

at least for me.

And it's tricky ‘cause, you know, all these things are

sort of overlapping.

But I picked out this intervention and --

because of its breadth.

It worked for so many different health problems,

and that’s what I found so cool about it.

So just to kind of walk you through a quick list,

so this intervention in patients with knee arthritis

who received one hour of treatment three times a week

reduced their rates of pain and disability by 47 per cent.

In older patients it reduced progression to dementia

and Alzheimer’s by around 50 per cent.

For patients at high risk of diabetes and coupled with

other lifestyle interventions, it reduced progression to

Frank diabetes by 58 per cent.

Post-menopausal woman who had four hours a week of

the treatment had a 41per cent reduction in the

risk of hip fracture.

It reduced anxiety by 48 per cent in a big meta-analysis.

Patients suffering from depression -- 30 per cent

were relieved with low dose and that bumped to

47 per cent as we increased the dose.

Following over 10,000 Harvard Alumni for over 12 years,

those that had the intervention had a 23 per cent

lower risk of death than those who didn’t get the treatment.

It’s the number one treatment of fatigue, and, of course,

the kind of outcome of choice or my favourite outcome

is quality of life, which is really all of the above,

and really about making your life better.

And this treatment has been shown over and over again

to improve quality of life.

So, the question is, "What’s –- what’s the medicine?"

And what is "23 and a Half Hours"?

So the medicine was exercise, mostly walking.

So not triathlons.

And let me just put it a different way.

I think what I’m asking you to do is if you think about

your typical day, so there's 24 hours,

and so you might spend most of your day, you know,

this varies obviously, but, you know, couch surfing,

sitting at work, obviously sleeping, and what the evidence

that I am going to show you kind of tells me

is the best thing you can do for your health

is to spend half an hour being active,

maybe an hour and that if you can do that you can realize

all the benefits I’ve described in the previous slide.

So let’s just take a quick walk through some of the literature.

So Stephen Blair, he is a professor at the

Arnold School of Public Health at the

University of South Carolina, and he looked at this in

what’s called the Aerobic Centre Longitudinal Study

which followed over 50,000 men and women over time.

And along the left side of this graph is something called

Attributable Fractions which is a kind of fancy word,

but it’s the estimate of the number of deaths

in a population that would have been avoided

if that specific risk factor had been erased.

So for example, turning a smoker into a non-smoker,

or a couch potato into a daily walker.

And along the bottom is the typical risk factors.

You can see the hypertension’s incredibly important,

and so on and so forth.

But the one that was most –- that kind of applied the

most risk was this sort of mysterious CRF which is

Cardio-Respiratory Fitness which is really low fitness.

So low fitness was the strongest predictor of death.

And this is important.

Most of the trails we see, to be honest, are funded by Pharma,

or other companies because they’ve got a drug for

hypertension or high cholesterol or diabetes.

And we rarely see fitness thrown in to the mix.

And so it’s nice to see a trial that’s not so siloed.

[sound of bicycle bell]

Blair’s work is interesting.

He also did another trial looking at obesity.

What he found was, you know, sort of two things.

One is obesity and no exercise – that’s a very bad combination

and that’s where we saw many of the negative consequences

of obesity from a health point of view.

But if the –- if the obese person was active,

even if they didn’t have the weight loss,

but were just active and obese, that was much,

much better and that the exercise ameliorated

much of the negative consequences of obesity.

So if exercise is the medicine, what’s the dose?

So when I think of dose, I think of how long,

how often and how intense?

I’m going to give you a slightly mixed message,

but essentially, more activity is better.

But I must say the rate of return seems to decline

after 20 or 30 minutes a day so if you’re being active

less than 150 minutes a week or more if you’re a kid --

an hour a day if you are a kid,

my flag goes up in the clinic.

So my personal take on this is that, you know,

the literature draws a very broad brush

and so we see big differences when somebody

goes from not doing anything to doing something.

And after that the return is more granular.

So if we took the nurse’s health study, women who went from

zero activity to just one hour a week,

reduced their heart disease rates by almost half.

So you can break it down so it can be 10 minutes,

10 minutes, 10 minutes if you want to do 30 minutes

of exercise so it can be broken into three.

Higher intensity -- it looks like it’s equivalent

to less time with lower intensity.

But I think obviously the clinical pearl is mostly of

thinking about your style and habits and your personal cues.

So if you’re only going to do it if it is pre-booked

with friends, you know, I’ve couples who take

a half hour walk every morning or evening to

organize their life.

A dog is a great walking coach.

[sound of dog barking]

The data’s showing 67 per cent of dog walkers

achieve the 150 minutes a week just with the dog walking.

And finally, of course, your commute.

You know, getting off a stop early, taking the stairs,

and so on and so forth.

So thinking about that, I’m just going to walk you through

some quick slices of the literature.

And the first one comes from Japan.

In the 90s, Japan required all employers to conduct

annual health screenings for their employees.

And so a large gas company in Japan called Osaka

used this to answer a great question.

So if people’s walk to work was longer,

did that reduce their chance of serious health problems?

So in this example, high blood pressure.

And what they found is under 10 minute walk, no difference;

11 to 20 minute walk, 12 per cent reduction

in rates of high blood pressure or hypertension;

and over 21 minute walk, a 29 per cent decrease

in rates of high blood pressure.

So the authors calculated that for every increase of

10 minutes in your walk to work there was a 12 per cent

reduction in the likelihood of getting high blood pressure.

The second exhibit is looking at stents.

So this is something we commonly do now in medicine.

So you can see on the left that the artery is blocked;

on the right, a vascular surgeon has gone in and put a balloon,

open it up and left a stent to keep it open,

which makes great sense.

So a German researcher named Rainer Hambrecht

looked at this with about 100 cardiac patients.

He got half the group to exercise and by that I mean

20 minutes a day on an exercise bicycle and

then a once weekly 60 minute aerobics class.

And the other half got the high tech stent and just

sort of normal activity.

And after one year, 88 per cent of the exercisers

were event-free compared to 70 per cent of the people

that got a stent.

So both worked, but I find it, you know, sort of incredible

that the low tech made a bigger difference.

And you have to remember that the stent just fixes

one part of the heart.

The next way to think about it is the reverse,

so what I call “sitting disease”.

We know that being sedentary is bad for your health

but a researcher named Leonard Veerman

wanted to quantify this and he did so down in Australia

in a big study that he did there.

They found comparative persons who watched no TV;

those that spent a lifetime average of six hours a day

watching TV can expect to live about five years less.

I mean that’s incredible.

But then I think, “Oh, who watches 6 hours of TV?”

It turns out the average adult in the USA spends about

five hours a day watching TV or screens.

So I find this fascinating that we never think of the TV

as something that’s bad for our health,

but clearly it’s as powerful as many other risk factors

for chronic disease.

So I’m just going to leave you with, well,

I guess, two quotes.

So one is Jerry Garcia, the singer who is the lead singer

for The Grateful Dead, and he said,

“Somebody has to do something.

It’s just incredibly pathetic that it has to be us”.

And I think that’s true, that in some ways it has to be us.

As Hippocrates said, “Walking is man’s best medicine”.

And so I’m going to finish by asking you a question.

And this may have some personal challenges for you,

so you know, you might be very busy with work

or kids or both and -- or you may be in pain

or have other priorities, but my question to you is,

“Can you limit your sitting and sleeping to just

23 and a half hours a day?”

So, something to think about.

Thank you very much.

[sound of marker on white board]