FINAL EXAM

Question 1

Relative Risk

Answer 1

Ratio between probability of event in exposed vs. not exposed groups

Question 2

Randomized Control Trials (RCT)

Answer 2

-Subjects randomly assigned to treatment or control groups
-Study done with follow-ups and results compared
-Used to test efficacy and effectiveness of different interventions within a sample population

Question 3

Efficacy Trials

Answer 3

*high internal validity/control

-Whether an intervention works in people who receive it
-“What happens when you exercise”
-Strict, standardized, supervised, research setting

*whether intervention works under ideal circumstances

Question 4

Effectiveness Trials

Answer 4

*high external validity/control

-Whether an intervention works in people who have been offered it
-“How to get people to increase and sustain exercise”
-Does it work in pragmatic/real-world settings
-Flexible, unsupervised, everyday clinical setting

*what must be done to change behaviours towards working to achieve goals

Question 5

Prospective Cohort Trials (Strengths and Weaknesses)

Answer 5

-Follows a group of individuals (cohorts) over time who differ in terms of factors under study to determine how these factors affect rates of an outcome
-Group of interest vs. comparison group, follow over time and compare outcomes

Strengths: large sample, generalizability, multiple outcomes can be studied

Weaknesses: expensive, confounding, changes in exposure of time

Question 6

Prospective Study vs. Retrospective Study

Answer 6

Prospective: participants enrolled before they develop disease/outcome

Retrospective: particpants enrolled who already have the disease/outcome

Question 7

Canadian 24-Hr Movement Guidelines (First-Time Observations)

Answer 7

Main idea= whole day matters (physical activity, sedentary behaviour and sleep)

First-time observations:
1. Recognized health benefits of LPA
2. Specific recommendations for sedentary behaviour (including screen time)
3. Removal of 10 min bout requirement for MVPA (all counts)
4. Recommendations for sleep duration and quality
5. That the composition of movement behaviours (sleep, sedentary behaviour and physical activity) across entire 24-hour day is associated with health**

Question 8

Principle Assertion of Guidelines

Answer 8

Past guidelines= behaviours in isolation/all separate, focus on single behaviour (as long as one met rest doesn’t matter)

Current guidelines= behaviours co-exist and influence one another (all parts matter, if one goes up another goes down)

1. Move more
2. Reduce sedentary time
3. Sleep well

Question 9

MVPA Definition

Answer 9

Moderate intensity= 3.0-5.9 METS on absolute scale, 5-6 on scale out of 10 (can talk but not sing)

Vigorous intensity= greater than or equal to 6.0 METS, 7-8+ on scale out of 10 (can only say a few words)

1. MVPA is associated with substantial risk reduction
2. Any amount counts
3. Reallocating more time into MVPA from other behaviours is associated with health benefits

*U.S. uses intensity (MET-minutes), Canada uses time (mins)

Question 10

MVPA Recommendations

Answer 10

1. MVPA accumulation of at least 150 mins/week (no 10 min bouts required)
2. Muscle strengthening activities for major muscle groups at least 2x/week
3. For 65+ do physical activities that challenge balance

1) No lower threshold for benefit
2) No upper threshold (no increased risk at high levels)
3) No obvious best amount and intensity doesn’t matter (dose-response)

Question 11

LPA Definiton

Answer 11

Light intensity= 1.5-2.9 METS on absolute scale, less than 5 out of 10

Includes daily living activities, casual walking, chores, gardening

*U.S.= no recommendation for LPA

Question 12

LPA Recommendations

Answer 12

1. Several hours of LPA including standing (no specific time recommendation like MVPA- not enough evidence)

*all intensities of objectively measured PA, including LPA, are associated with substantially reduced risk of mortality in a dose-response manner

Question 13

Sedentary Behaviour Recommendations

Answer 13

1. Limit sedentary time to 8 hours or less, including:
2. No more than 3 hours of recreational screen time
3. Breaking up long periods of sitting as often as possible

Sedentary= 1.1-1.4 METS (sleep= 1 MET)

Question 14

LPA and MVPA on Cancer Risk

Answer 14

LPA: 30 mins/day more significant than 30 mins/day of MVPA in reducing risk of cancer

MVPA: 30 mins/day has no effect

Question 15

LPA and MVPA on CVD Risk

Answer 15

Both LPA and MVPA significantly decrease risk of CVD mortality

Question 16

PA and CRF on All-Cause Mortality

Answer 16

Decrease PA= decrease CRF= increase risk

*increasing CRF lowers risk of all cause mortality
*measures of CRF are associated with morbidity and mortality independent of commonly obtained risk factors

Question 17

PA on T2D

Answer 17

Exercise is associated with risk reduction of T2D independent of intensity (any type of exercise counts)

-PA increases risk reduction in a dose-dependent manner (just about amount of time, not intensity)
-Increase PA, decrease obesity, decrease T2D
-Resistance training also decreases risk of T2D

Question 18

PA on Blood Pressure

Answer 18

Exercise duration not associated with reductions in SBP in dose response manner (appears to be a threshold; no effect until a certain point)

-For any given BP inactivity is associated with highest risk and MVPA associated with smallest risk
-As BP increases the risk of mortality increases across all intensities
-For any given BP the risk of mortality significantly higher in those who are inactive than those performing any type of intensity
*any intensity has benefit for reducing risk of mortality

Dose response relationship b/t PA levels and incident hypertension