Seminar - Exercise

Question 1

is measuring exercise in population easy?

Answer 1

no its a complex behaviour with several domains like occupation, leisure, travel, domestic

Question 2

why do we need accurate measures of exercise

Answer 2

inaccurate measurement leads to misclassification bias
- random nondifferential misclassification bias - exposed and unexposed groups appear more similar
non random differential misclassification bias - more likely in those who have the outcome of interest than those who dont

Question 3

outline self reporting

Answer 3

most commonly used
questionnaire
subject to bias
participants might recall some types of activity more accurately than others

Question 4

outline the Baecke questionnaire

Answer 4

1. work activity
2. sports activity
3. leisure activity

Question 5

what is the RPAQ questionnaire

Answer 5

1. physical activity at home e.g tv viewing, mode of transport, stair climbing
2. physical activity at work
3. recreation - activities in leisure time

Question 6

what are 2 ways to objectively assess physical activity

Answer 6

• doubly labelled water (energy expenditure)
• wearable sensors

Question 7

what is doubly labelled water

Answer 7

gold standard for measuring energy expenditure
expensive and time consuming
participant drinks water in which hydrogen and oxygen are labelled (replaced) with deuterium and oxygen-18
measure CO2 production
- no info on type of activity undertaken

Question 8

outline combined heart rate monitoring and accelerometry

Answer 8

allows individually calibrated heart rate workload relationship to be established and used to estimate energy expenditure
data from accelerometer informs energy expenditure estimate
expensive and time consuming

Question 9

what are limitations with objective measurements

Answer 9

lack of standardisation/transparency in algorithms used
lack of context and identification of different types of activity