week 14, 15, 16 Flashcards
(32 cards)
what is PA
any bodily movement produced by skeletal muscles that increase energy exposure
what is exercise
planned, repetitive and purposeful bodily movement done to improve or maintain the components of physical activity
what is sport
more structured exercise with specific set of rules and generally involves competition
what are the adult PA guidelines 18-64
150 minutes moderate intensity aerobic activity or 75 minutes vigorous intensity aerobic activity every week, two days including strength training, all adults should minimise sedentary time
what does 1 MET =
rest, metabolic rate of 3.5ml/kg/min
what is <6 METs
non-vigorous PA
what is > 6 METs
vigorous PA
What is a direct measure of physical activity
directly measuring energy cost of movement itself
what is an indirect measure of physical activity
measures aspects associated with physical acitivty (fitness, body comp, responses, self report)
what type of measure is calorimetry
direct and objective
measures energy expenditure through heat production/ loss directly
highly accurate in measuring TEE
cons of calorimetry
requires individuals to be sequestered in chambers,
expensive,
limited tasks,
impractical for large pop groups,
assumes body temp is constant,
must correct for convection, radiation, evaporation and conduction
what is indirect calorimetry
object measure of a proxy heat production/ loss by measuring oxygen consumption and/ or CO2 production
limitations of indirect calorimetry
assumes steady- state aerobic metabolism
cannot capture aerobic metabolism
frequent recalibration of oxygen analysers as they are susceptible to drift
affected by hyperventilation or hypoventilation
what type of measurement is doubly labelled water
objective, indirect
gold standard for measurement of energy expenditure
how is doubly labelled water conducted
administration of two stable isotopes of water, provides a measure of CO2 production, EE established using equations
limits of doubly labelled water
cost
technical complexity
cannot discriminate between activity types, patterns or evaluate exercise intensity
how do accelerometers measure activity
record acceleration data in counts
measured in Hz (represents data points per second)
what are counts
aggregated values that summarise the magnitude of acceleration over a set time period
correspond to acceleration
why are counts used
easier to classify activity intensity levels than raw acceleration data
what is signal rectification and why is it important
converts negative values to positive,
care about magnitude not direction
what is proprietary filling
bandwidth filters applied to remove acceleration frequencies outside normal human movement, kept between 0.25-2.5 Hz
epochs for adults vs children
adults: 60 seconds
children: 15 seconds
limitations of acelerometers:
swimming, cycling, weight training, does not count for non-movement EE, acceleration and deceleration phases contribute equally, assumes constant efficiency, difficult in large pop studies, can be expensive
4 things to measure PA
frequency, intensity, modality, duration
