physical inactivity

Question 1

physical inactivity

Answer 1

• bodily movement generated by skeletal muscles resulting in energy expenditure (heat production).
• amount of energy you are using in exercise (energy metabolism)
• 2 divisions
• non-exercise activity thermogenesis (NEAT)
• voluntary physical activity
• an insufficient physical activity level to meet present physical activity recommendations
• different all depending on how an individual lives

Question 2

metabolic cart

Answer 2

• amount of O2 being used
• not as convenient to measure O2

Question 3

metabolic chamber

Answer 3

• longer O2 testing
• can be done from days - weeks
• uses sample gas
• how much O2 is used over time

Question 4

doubly labelled water technique

Answer 4

• consume a water with H2O and O2 (isotopes) to see how the different isotopes are excreted in different ways
• released through urine , evaporation, sweat
• how much of this release was due to metabolism
• not time bound

Question 5

METS

Answer 5

• 1 MET = amount of oxygen consumed at rest , standardizes physical activity in VO2
• normalizes the metabolic demand of a given activity / across activities
• 1 MET = 3.5 ml O2 / kg / min
• originated from the resting VO2 from one 70kg, 40 year old man and his value ^^
• MET compendium website to convert the cost of VO2 –> METS

Question 6

classifying energy expenditure through FIT

Answer 6

• frequency x duration x intensity x body mass
• equals different levels of energy expenditure depending on how you combine them

Question 7

classifying movement behaviors

Answer 7

• spectrum of movement behaviors
• also includes activities in other categories like sleep, sedentary behavior
• holistic view on physical activity

Question 8

sitting

Answer 8

• a position in which one’s weight is supported by one’s buttocks rather than one’s feet, and in which one’s back is upright
• there is sitting doing nothing and sitting but doing something

Question 9

lying

Answer 9

• being in a horizontal position on a supporting surface

Question 10

standing

Answer 10

• a position in which one has or is maintaining an upright position while supported by one’s feet

Question 11

sedentary behavior

Answer 11

• any waking behavior characterized by an energy expenditure of less than 1.5 METS, while in a sitting, reclining, or lying posture

Question 12

sedentary behavior patterns

Answer 12

• have to take into account all aspects of the activity spectrum
• there is not just active and not just sedentary

Question 13

total 24hr movement behavior

Answer 13

• 4 different possibilities in the range of sedentary - physical activity
• can be in both category
• NOT mutually exclusive

Question 14

reasons to measure physical activity levels

Answer 14

• direct relationship with disease endpoints (morbidity/mortality)
• indirect relationship with disease through the effects of activity on diet or body weight (nutrition)
• ability to study physical activity patterns , determinants, and barriers in different groups
• more relevant for a wider segment of the population
• to evaluate physical interventions

Question 15

weekend warrior

Answer 15

• challenges vigorous physical activity
• as long as you get 150 min of activity per week it reduces mortality, CVD, and cancer mortality
• 1-2 sessions per week to meet the 150min requirement

Question 16

interaction between types of activity (Tv study)

Answer 16

• 240,000 adults (50-71)
• moderate to vigorous activity
• TV viewing time as sedentary behavior and CVD risk
• tv time vs exercise
• 100% risk if you watch a lot of TV but exercise a lot

Question 17

classifying inactivity by energy expenditure (METS)

Answer 17

• sedentary activity : 0-1.5
• light PA: 1.5-3
• moderate PA: 3-6 (most common with athletes and gen pop)
• vigorous PA: 6+ (usually combined with moderate)

Question 18

methods for assessing physical inactivity

Answer 18

• gold standard is to measure over 7 days
• best is also to assess over periods of time
• use reliable and valid assessment methods
• reliable : reproducible, giving the same results for a given amount of physical activity
• valid: accurately measures what it is intended to measure

Question 19

physical activity questionnaires

Answer 19

• self reporting
• IPAQ

Question 20

self reporting questionnaires, pros and cons

Answer 20

• pros –> easy to use (implementing/scoring), inexpensive, easy to deliver on a large scale
• cons –> social desirability (BIAS, not full truth, socially accepted by sounding better) , memory/ recall (harder over longer periods of time), familiarity with terminology.

Question 21

IPAQ

Answer 21

• developed over past 20+ years
• actually captures what people are doing
• short and long versions for epidemiological and research purposes
• many validation studies across a variety of populations
• translated into 15+ languages
• incorporates sedentary behaviors
• large range of validity in comparison objective measures

Question 22

subjective assessment

Answer 22

• self-report measures of physical activity

Question 23

objective measurements of activity

Answer 23

• pedometers (step counters)
• accelerometers (motion in 3D)
• heart rate monitors

Question 24

pedometers

Answer 24

• detect vertical accelerations of the body and record a “step” when vertical acceleration exceeds a threshold value
• accurate for recording the number of steps taken and distance walked
• increased reliability for faster walking and running paces because stride is longer and there is a clear heel strike
• accuracy not affected by walking or running surface
• relationship between step counts and energy expended strongest for moderate-intensity activities
• step count is more accurate than kilocalorie estimates

Question 25

problem with pedometers

Answer 25

- decreased sensitivity if tilted away from the vertical plane (not worn properly) - hard to track for obese people if they walk slower if the belt is tilted - ankle device is sensitive enough to detect frail, slow, shuffling steps

Question 26

accelerometers

Answer 26

- measure movement based on acceleration and deceleration of the body - can be work on trunk or limbs - measurements are proportional to muscular forces (picks up gravitational acceleration) - most results in proportion to energy expenditure - provides FIT of PA - best types measure in three planes (vertical, horizontal, mediolateral)

Question 27

activPAL

Answer 27

- picks up sedentary behavior - worn on the thigh - helps with sitting activities (swimming and cycling)

Question 28

parameter

Answer 28

- can be worn on sports bra / chest - ECA waveforms

Question 29

actigraph

Answer 29

- research grade - very good - worn on the hip and wrist

Question 30

advantages of accelerometers

Answer 30

- small size and ability to record data over long periods of time - ability to download data and to segment physical activity time periods - same accelerometers can be worn repeatedly by different participants

Question 31

limitations of accelerometers

Answer 31

- requires more time and resources - technical expertise, hardware, and software needed to calibrate - single-plane models may not accurately detect movements from activities such as bicycling, weightlifting, or swimming - unable to detect increased activity level resulting from upper body movement, carrying a load, or surfaces - equations that estimate energy expenditure may not apply to free-living situations (need well studied devices and validity)

Question 32

heart rate monitoring

Answer 32

- HR is linearly related to VO2 during submaximal aerobic activities - HR is good for telling us how how hard we work = exertion - good method of physical activity assessment - very practical in the field - able to store data - is able to estimate frequency, intensity, and time of physical activity for days-weeks

Question 33

calorimetry

Answer 33

- indirect is highly correlated (0.87) with HR monitoring - there is a stronger correlation with accelerometers than calorimetry for lifestyle activities - wearing an accelerometer and a HR monitor together may improve energy expenditure estimation and classification and time spent in light, moderate, and hard activity

Question 34

limitations of a HR monitor

Answer 34

- HR is increased by temp, humidity, and high altitude so these may result in overestimation of energy expenditure. - emotional state, hydration status, and type of contraction (static vs dynamic), and the amount of muscle mass recruited will affect HR, independent of physical activity

Question 35

monitors that use multiple inputs

Answer 35

- combos of accelerometers and physiological signals to predict/calculate energy expenditure - SenseWear Armband - Actiheart

Question 36

GPS monitoring

Answer 36

- provides accurate assessments of speed from slow walking to fast running - can be used indoors and outdoors - cannot be used for stationary activity

Question 37

physiological sensors

Answer 37

- can be embedded into clothing with wearable digital camera

Question 38

objective measures of activity

Answer 38

- different charts of advantages and disadvantages of pedometers, accelerometers, and HR monitors