Measurig Physical Activity Flashcards
What is in doubly labelled water?
2 hydrogen and 18 oxygen ions
How does hydrogen leave the body
Urine, sweat or vapour
How does oxygen leave the body?
Water or carbon dioxide
How is energy expenditure estimated for doubly labelled water?
Difference in the rate of loss between hydrogen and oxygen allows the co2 production to be estimated
Oxygen calculated from the co2 production
Energy expenditure is calculated from the ratio of CO2 to oxygen
What are the pros of doubly labelled water
Gold standard
Simple
Non invasive
Administration of water samples, urine and saliva
What are the cons of doubly labelled water?
Expensive
Time consuming
Can’t tell different rates of energy expenditure
Physical activity questionnaires pros
Quick and easy
Lots of responses
Cheap
Estimation of energy expenditure
Physical activity questionnaires cons
Validity
People can lie
Non reliable
Adults overestimate their activity by 70% Adamo et al 2008
How much do adults overestimate their physical activity levels according to adamo et al 2008
70%
Pedometers pros
Counts steps
Easy to understand
Information readily available
Easily accessed- phones, fitbits, watch’s
Pedometer cons
No information on intensity of exercise
Less accurate for obese individuals
What did Welk et al 2004 say about pedometers?
Give better values for moderate rather than vigorous activity
Heart rate monitor pros
Easy to use
Cheap
Easy to understand
Heart rate monitor cons
Other factors can affect heart rate temperature, humidity, emotional state, hydration
Individual hr responces
Unable to determine the type of physical activity
Accelerometer pros
Measures movement in all planes
Strong data provided
Records for a long period of time
Records time, duration, and frequency
