Lecture 9: Physical Activity

Question 1

What is physical activity?

Answer 1

“any bodily movement produced by skeletal muscles that requires energy expenditure”

Question 2

What are subjective measures of PA?

Answer 2

• Survey/questionnaire
• Self report

Question 3

What are objective measures?

Answer 3

• Pedometers
• Accelerometry

Question 4

What is a pedometer?

Answer 4

step counter

Question 5

What are accelerometers?

Answer 5

sophisticated, expensive technology, high tech version of an apple watch - can be worn on hips, wrist, thigh

Question 6

What is PA measured in?

Answer 6

METS - Metabolic Equivalents

Question 7

How many METS is considered sedentary behaviour?

Answer 7

<1.5 METs

Question 8

How many METS is considered light PA?

Answer 8

1.5 to 3 METS

Question 9

How many METS is considered moderate to vigorous PA?

Answer 9

> 3 METS

Question 10

What is the recommended PA for adults per week?

Answer 10

Minimum 150-300 minutes of moderate per week
OR
Minimum 75-150 minutes of vigorous per week

Question 11

What are the positive health benefits of PA?

Answer 11

• all cause mortality
• CV disease mortality
• hypertension
• specific cancers
• type 2 diabetes
• mental health
• cognitive health
• sleep

Question 12

What is the relationship between PA and all-cause mortality?

Answer 12

Inverse relationship between level of PA and risk of mortality

Question 13

What is meta-analysis?

Answer 13

data from a huge group of people, different populations from different studies

Question 14

What is the lower threshold for health benefits from PA?

Answer 14

there is no lower threshold for health benefits - anything is better than nothing

Question 15

What is the upper threshold for health benefits from PA?

Answer 15

there is limited evidence to identify the exact point at which the harms of PA out weigh the benefits - benefits seem to plateau towards the upper end

Question 16

What is the recommendation for muscle strengthening in adults per week?

Answer 16

2 times a week do muscle-strengthening activities that involve all major muscle groups on 2 or more days a week

Question 17

What are the limitations of muscle-strengthening activities?

Answer 17

• Lack of education on muscle groups
• Confusion on intensity levels
• Everyone feels intensities differently

Question 18

What number is considered statistically significant?

Answer 18

less than 0.05

Question 19

What is the relationship between muscle strengthening activity and risk of all cause mortality?

Answer 19

Independent of aerobic activity, muscle strengthening activity is associated with a lower risk of all cause mortality - insufficient evidence to specify a duration

Question 20

What should adults do if they are not meeting these recommendations?

Answer 20

• Doing some activity will benefit their health even if it is not enough to meet
• Start with small amounts and increase over time

Question 21

What are the global PA patterns?

Answer 21

Globally we are not meeting WHO recommendations

Question 22

How do men compare to women in terms of PA?

Answer 22

Men are statistically more likely more likely to be physically active

Question 23

What are global PA looking like over time?

Answer 23

Overall we are seeing people be less active

Question 24

Are adults or adolescents more physically inactive?

Answer 24

adolescents

Question 25

Are physical inactivity and sedentary behaviour the same?

Answer 25

No they are not the same

Question 25

Why do we want to increase rates of adolescents activity?

Answer 25

The idea is that if you are physically active as a child you are more likely to be physically active later in life, there is lots of initiatives to increase adolescent physical activity

Question 26

What is physical inactivity?

Answer 26

Accruing insufficient physical activity to meet activity guidelines

Question 27

What is sedentary behaviour?

Answer 27

Any waking behaviour characterised by an energy expenditure <1.5METS, while in a sitting, reclining or lying posture

Question 28

How is TV time associated with all cause mortality?

Answer 28

TV time is very commonly associated with sitting and therefore sedentary behaviour.
Before 8 hours - you’re generally OK. The change in risk after 10 hours a day is very significant

Question 29

How is TV time associated with CVD mortality?

Answer 29

After about 7/8 hours per day the risk increases dramatically for CVD mortality

Question 30

What is the relationship between TV time and type 2 diabetes?

Answer 30

Linear relationship between TV viewing and type 2 diabetes

Question 31

Why is there a linear relationship between TV time and type 2 diabetes?

Answer 31

A lot of behaviours when you are sedentary and especially watching TV are associated with increased risks of diabetes and CVD

Question 32

What have increased breaks in sedentary time been associated with?

Answer 32

Improved measures of body composition, improved postprandial plasma TAG, glucose and insulin responses

Question 33

What is the WHO recommendation for sedentary behaviour?

Answer 33

Limit time spent sedentary, replace sedentary time with PA of any intensity

Question 34

What is the relationship between time spent sitting and the amount of exercise you have to do?

Answer 34

The more minutes of PA you do per day, the more time you can spend sitting
Also, the less time you spend sitting, the less PA you need to do to be low risk