Kinesiology 1070A/B Lecture Notes - Lecture 5: Light Work, Telomere, Bone Density
11 Jun 2018
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Too Much Sitting
Sedentary Behaviour
• A akig ehaior haraterized a eerg epediture ≤ .5 etaoli
equivalents (METs) while in a sitting or reclining position
** One MET is defined as 1 kcal/kg/hour and is roughly equivalent to the energy cost of sitting
quietly. A MET also is defined as oxygen uptake in ml/kg/min with one MET equal to the
oxygen cost of sitting quietly, equivalent to 3.5 ml/kg/min.
Tremblay et al 2010
- Some people might experience bed rest because of certain events
- Sitting for work- sitting and using a computer, in class etc
Distribution of employed population
- A lot of people are employed in fields that promote sedentary behavior
- Ill effects of sitting have been known since 60. For eg, bus driver dies before the ticketer
(guy who goes up and down and moves all day)
Historical Perspective- A case study
- First evidence that inactivity is bad for you was published in the Lancet by Morris et al in
1953
- Included in their seminal work was an ecologic study of heart disease mortality and
occupational physical activity
People who do light work
have high mortality rate
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Recent Evidence
**Study
Does physical activity attenuate, or even eliminate, the detrimental association of
sitting time with mortality? Meta-analysis from more than 1 million men and women
By Ekelund
ThThis graph shows link between deaths
and amount of time being active and
inactive
- - Inactive people die earlier (and
more often?) and the relationship is
more obvious as you increase your %
of inactive sitting
Si Sitting time vs hazard ratio
35 mets- an hour- protective benefits
to hazard ratio
30 mets- less than an hour
16 mets- half hour(guidelines lie for
people)
2.5 mets- 5 mins- hazard ratio goes up
- You reduce your activity profile-
there’s a ireased risk as ore tie
is spent sitting
- The more you sit the more your
hazard risk profile goes up
Tg this focuses on TV viewing
- - No group is safe
- - Also associated with eating
• Find interpretation to this graph
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find more resources at oneclass.com
Interpretation- High levels of moderate intensity physical activity (60-75mins/day) seem to
eliminate the increased risk of death associated with high sitting time.
• However, this high activity level reduces but does not eliminate increased risk
associated with TV viewing
**Study
Physical Activity and Morality: The potential impact of sitting
By Katzmarzyk
Health Consequences of Sedentarism
Compromises- Bone density and Vascular Health
Risk Factors- Obesity and Some cancers
How strong is the association?
- Negative effects of sitting are seen among all ages
Ha Hazard Ration vs hours of sitting
Th These results indicate that a strong public
health focus should remain on increasing level
of MVPA, irrespective of amount of time
people are sitting for.
\ - People who are forced to sit all day should
have high physical activity goals
- - Push people to be physically active
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Sedentary behaviour: a(cid:374)(cid:455) (cid:449)aki(cid:374)g (cid:271)eha(cid:448)ior (cid:272)hara(cid:272)terized (cid:271)(cid:455) a(cid:374) e(cid:374)erg(cid:455) e(cid:454)pe(cid:374)diture (cid:1005). 5 (cid:373)eta(cid:271)oli(cid:272) equivalents (mets) while in a sitting or reclining position. ** one met is defined as 1 kcal/kg/hour and is roughly equivalent to the energy cost of sitting quietly. A met also is defined as oxygen uptake in ml/kg/min with one met equal to the oxygen cost of sitting quietly, equivalent to 3. 5 ml/kg/min. Some people might experience bed rest because of certain events. Sitting for work- sitting and using a computer, in class etc. A lot of people are employed in fields that promote sedentary behavior. Ill effects of sitting have been known since 60. For eg, bus driver dies before the ticketer (guy who goes up and down and moves all day) First evidence that inactivity is bad for you was published in the lancet by morris et al in. Included in their seminal work was an ecologic study of heart disease mortality and occupational physical activity.
