10. Exercise Is Medicine (2nd half)

Question 1

4th leading risk factor for global mortality?

- # of deaths per year

Answer 1

physical inactivity

~ 3.2 million

Question 2

Benefits of regular moderate physical activity (according to WHO)?

Answer 2

control body weight and reduce risk of:

• cardiovascular disease
• diabetes
• colon and breast cancer
• depression
• bone fractures

Question 3

WHO exercise recommendation?

- how many people reach this

Answer 3

moderate-to-vigorous physical activity

• 150 mins in 10 mins bouts
• only 15% of adults meet this

Question 4

Exercise pill?

- how it works

Answer 4

AICAR

• activates AMPK
• artificially tells body there is a demand

Question 5

Exercise pill - sedentary mouse study (AICAR)

- good + bad

Answer 5

Good

• induced metabolic genes (carb/fat metabolism through AMPK)
• enhanced running endurance

Bad

• expensive ($1000 per 10g)
• enlarged liver (weight)

Question 6

Typical causes / diseases associated with enlarged liver (6)

Answer 6

• excessive alcohol use
• congestive heart failure
• glycogen storage disease
• viral hepatits
• liver cancer
• steatosis (fatty liver)

Question 7

Effects of exercise

- can drugs do this?

Answer 7

Contracting skeletal muscles elicit a host of metabolic and mechanical signals that contribute to muscle adaptations

• enhanced performance, fibre type conversion, more oxidative phenotype, multiorgan health benefits
• drugs can mimic only some of the benefits

Point
- no single pill will show same benefits of regular exercise

Question 8

what is Metformin

Answer 8

antidiabetic drug (preventative)
- works through AMPK

Question 9

AMPK levels in obese/diabetic muscle

Answer 9

Normal

• not a problem in obese/diabetic
• viable pharmacological target (improve gluc uptake and FA oxidation)

Question 10

Study: metformin vs lifestyle modification (diabetes)

• over 4 years
• exercise and follow food pyramid

Answer 10

Improved blood glucose in both lifestyle and metformin
- fasting and glycosylated hemoglobin

Reduced incidence of diabetes

• metformin: 31%
• exercise: 58% (better)

Question 11

why measure glycosylated hemoglobin?

Answer 11

red blood cells lifespan ~120days

• good “chonic marker”
• blood glucose changes rapidly, not as good chronic marker

Question 12

Meta-analysis: exercise vs drugs (mortality risk)

Answer 12

No statistical diff b/w drugs and exercvise in CHD and prediabetes

Exercise more effective in stroke

Diuretics more effective than exercise in heart failure

Question 13

Problems with drug vs exercise studies

Answer 13

evidence on health benefits of exercise smaller than drugs

consider requiring pharmaceutical sponsors of new drugs to “include exercise” in clinical trials
- have control group exercise

Question 14

Benefits of a single bout of exercise

Answer 14

improve insulin sensitivity and response to high fat meal
- up to 48 hours**

Study

• improve fasting and postprandial (after meal) plasma TAG (markers of CVD risk)
• better response on postprandial than calorie deficit alone
• exercise PRIOR to high fat meal improves response (timing key)
• walking (real-world recommendations)

Question 15

benefits of regular exercise without weight loss

Answer 15

reduce “visceral” fat

- obese active/fit LOWER risk of heart disease than lean adults sedentary/unfit

Question 16

Study: obesity vs cardiovascular fitness

• CVD and all cause mortality
• assesed CVD risk factors
• blood cholesterol and glucose, blood pressure, presence of disease (heart disease and diabetes)

Answer 16

normal, overweight and obese

• high cardio fitness, low risk for all
• low cardiovascular fitness, strong and INDEPENDENT predictor of CVD and all cause mortality