Exercise and Cancer Risk Reduction: Epidemiological Evidence

Question 1

What are Epidemiological Studies?

Answer 1

Population based studies that examine cohorts over time.

Question 2

What does Epidemiological studies control for and examine?

Answer 2

Cofounding factors (other factors that can cause cancer) and examine relationships between variables of interest (physical activity and cancer diagnosis

Question 3

What is the ideal time for exercise per week?

Answer 3

150 mins moderate
75 mins moderate-vigorous
resistance training x2 per week

Question 4

What is a Case Control Study?

Answer 4

Not as common, have a group of “cases” (people with cancer) and matched “controls” (similar people without cancer) and compare the two (unknowingly) on different features

Question 5

What is an Observational epidemiologic study?

Answer 5

More common, follow a large group of people (10,000 or more) to see who develops an outcome of interest and compare differences between groups

Question 6

Example of observational epidemiologic study

Answer 6

See who developed cancer and who didn’t

Question 7

4 domains of Physical Activity

Answer 7

1. Occupational - workplace
2. Recreational - sports, gym
3. Household - Gardening, vacuuming
4. Transport - Biking, taking the stairs

Question 8

3 Volumes of Physical Activity

Answer 8

1. Frequency - How often
2. Duration - How long
3. Intensity - Light, moderate, vigorous

Question 9

What is Sedentary behaviour?

Answer 9

Any walking activities with an energy expenditure of less than 1.5 METS

Question 10

Example of Sedentary behaviour

Answer 10

Sitting in class, driving a car, lying down

Question 11

Is sleeping a sedentary behaviour?

Answer 11

No

Question 12

Is high sedentary always equal to low Physical activity?

Answer 12

No, you could have high sedentary behaviour while also having a high PA level

Question 13

What percent of individuals spend their time awake in sedentary behaviours?

Answer 13

55%

Question 14

How did humans physical activity levels evolve?

Answer 14

Humans evolved with high levels of energy expenditure from hunting and gathering resources (no cars and tv back then)

Question 15

How can we decrease sedentary behaviours?

Answer 15

• replacing it with some light intensity activities
• Breaking up sedentary time by standings or walking

Question 16

What percent does sedentary behaviour increase colon cancer risk?

Answer 16

28-44%

Question 17

What is the recommended physical activity for reducing colon cancer risk?

Answer 17

• occupational and recreational activity
• 30-60 mins/day of moderate-vigorous PA

Question 18

What is the recommended physical activity for reducing breast cancer risk?

Answer 18

• recreational/household activities
• 4-7 hours per week of moderate to vigorous activity

Question 19

What is the recommended physical activity for reducing endometrial cancer risk?

Answer 19

• household activity, cycling/walking
• 1 hour/day of moderate-intensity PA

Question 20

Why is research limited to Physical activity reducing risk of prostate cancer

Answer 20

Many men die with undiagnosed prostate cancer (slow growing)

Question 21

What is the recommended physical activity for reducing risk of lung cancer?

Answer 21

• Recreational PA
• Limited/moderate evidence

Question 22

Is there a relationship between physical activity and invasive and in situ breast cancer risk?

Answer 22

Yes

Question 23

Does PA reduce the risk of colon cancer in women?

Answer 23

Yes, 50% reduction when exercising 4 or more times (mod-vig)

Question 24

What 3 cancers does sedentary behaviour increase risk?

Answer 24

1. Colon
2. Lung
3. Endomertial