Sedentary behaviour Flashcards
the whole proposition of the sedentary behaviour class?
sedentary behavior (too much sitting) is a deeply-embedded public health problem, which is additional to lack of physical activity (too little exercise)
what is a confounder?
- what are confounders for sitting too much being a risk factor for all-cause mortality?
- a variable that correlates with both x and y –> causes confusion in true relationship
- sex, age, genetics, diet, environment (climate), job, family income, neighbourhood safety, rich vs low income, level of PA
what does it mean if something is an independent risk factor?
means that even if we control for all the other confounding variables, there is sill an association btw x and y
- ie: sitting is a risk factor for all-cause mortality, independent of levels of PA –> even if you control for PA, still an association btw sitting and mortality
how to establish sedentary behaviour ish? vs light vs moderate
- goal of public health PA guidelines?
using METs!
0.9 = sleeping
1.0 - 1.8 = sedentary
- 1.0 = sitting quietly (TV viewing)
- 1.5 = sitting (talking)
- 1.8 = sitting (desk work
2.0 - 3.0 = light
- 2.0 = standing
- 2.5 = slow walking
> 3.0 = moderate
- 3.8 brisk walking
- increase time spent in mod-vigorous activity!
how to apply public health framework to sedentary behaviour research?
4 steps ish
- epidemiology: tracking PA (time surveys) vs sedentary and look at health outcomes –> see if there is an association
- if there it, generate hypothesis –> which leads to clinical/interventional: sample people, check blood work and BP + sedentary + PA levels vs health outcomes
- if you still see a trend, measure effectiveness/efficacy of intervention –> how to decrease risk factors –> change/modify PA levels and sedentary levels –> see if effect on health outcomes
- translational –> how to get the word out? implement public health policy and programs to improve the health outcome
*still early days for sedentary behaviour research (vs domains for PA)
canadian sedentary behaviour guidelines for children 5-11 yo (3 ish)
*1st country in world to come up with sedentary behaviour guideline!
- should minimize time spent being sedentary each day by:
1. limiting recreational screen time to no more than 2h per day –> lower levels associated with additional health benefits
2. limiting sedentary (motorized) transport, extended sitting and time spend indoors throughout the day
*encourage active and outdoors activities!
what counts as being sedentary for children? (5)
- sitting for long periods
- using motorized transportation (bus/car)
- watching television (electronic babysitter)
- playing passive video games
- playing on computer
spending less time being sedentary can help children do what (6)
- maintain healthy bw
- do better at school
- improve self-confidence
- have more fun with friends
- improve their fitness
- have more time to learn new skills
what are 3 things to help children swap sedentary time with active time?
- active transportation (vs driving to school) –> walk to school with groups of kids from neighbourhood
- active play (vs TV) (ie after school) –> limit after school TV watching. plan time outdoors instead + encourage kids to participate in sports
- active family time: instead of video games, introduce family to active games
what objective measurement is changing the research frame in sedentary behaviour? describe
accelerometers!
- Activ graph: small, lightweight, unobtrusive –> can record time, duration, frequency and intensity (light vs mod-vig) of mvt in one-minute epochs
- Activ pal: very good for measuring sedentary time (sitting/lying) + number of transitions btw sitting and standing (reduced for very sedentary people)
NHANES sedentary time in US population –> what is the trend as age increases for time spent in sedentary behaviour?
sedentary behaviour increases!
- lowest = 6-11 yo
- highest = 70-85 yo
BUT 12-15 and 16-19 have higher time than 20-59!
what is the adult’s overall daily behaviour patterns distributed btw physically active and sedentary time? (pie chart)
- 9.3h sedentary time (sitting, studying, in class…)
- 6.5h light-intensity activities
- 0.7h mod-vig intensity activities
describe modern sitting-oriented society
- wake up (7am)
- 15min sitting breakfast + 45min transport to work sitting in car/traffic
- work 3.5h + lunch sitting 30min + work sitting 4h
- transport back home sitting (45min) + 30min dinner sitting
- 4h watching TV + maybe walk 30min
- sleep 11pm
from 2 to 5 –> 15.5h of sitting opportunity…
trends (from 1981 to 2002) in households with entertainment equipment that promotes too much sitting (describe graph)
- VCR/DVD (from 1981), computer (from 1986) and internet (from 1996) increase from 10% to 60% ish throughout the years
- one TV at 70% in 1981, decrease to 30% in 2002
- 2+ TV from 55% in 1981, increase to 90% in 2002
- cable TV from 70% in 1991 to >90% in 2002
prevalence of overweight children vs hours of tv watched per day: describe graph (boys vs girls)
more overweight children as hours of TV watched per day increases!
- <1h/day = around 20% obesity prevalence (more boys than girls)
- 2-3h = 25-30% (more boys than girls)
- >4h = 30-35% (more girls than boys)