quarta-feira, 25 de Setembro de 2013

Sitting Time and Mortality from All Causes, Cardiovascular Disease, and Cancer

KATZMARZYK, PETER T.1; CHURCH, TIMOTHY S.1; CRAIG, CORA L.2; BOUCHARD, CLAUDE1

Abstract

Purpose: Although moderate-to-vigorous physical activity is related to premature mortality, the relationship between sedentary behaviors and mortality has not been fully explored and may represent a different paradigm than that associated with lack of exercise. We prospectively examined sitting time and mortality in a representative sample of 17,013 Canadians 18-90 yr of age.
Methods: Evaluation of daily sitting time (almost none of the time, one fourth of the time, half of the time, three fourths of the time, almost all of the time), leisure time physical activity, smoking status, and alcohol consumption was conducted at baseline. Participants were followed prospectively for an average of 12.0 yr for the ascertainment of mortality status.
Results: There were 1832 deaths (759 of cardiovascular disease (CVD) and 547 of cancer) during 204,732 person-yr of follow-up. After adjustment for potential confounders, there was a progressively higher risk of mortality across higher levels of sitting time from all causes (hazard ratios (HR): 1.00, 1.00, 1.11, 1.36, 1.54; P for trend <0.0001) and CVD (HR:1.00, 1.01, 1.22, 1.47, 1.54; P for trend <0.0001) but not cancer. Similar results were obtained when stratified by sex, age, smoking status, and body mass index. Age-adjusted all-cause mortality rates per 10,000 person-yr of follow-up were 87, 86, 105, 130, and 161 (P for trend <0.0001) in physically inactive participants and 75, 69, 76, 98, 105 (P for trend = 0.008) in active participants across sitting time categories.
Conclusions: These data demonstrate a dose-response association between sitting time and mortality from all causes and CVD, independent of leisure time physical activity. In addition to the promotion of moderate-to-vigorous physical activity and a healthy weight, physicians should discourage sitting for extended periods.
http://journals.lww.com/acsm-msse/Fulltext/2009/05000/Sitting_Time_and_Mortality_from_All_Causes,.5.aspx?utm_source=exacttarget&utm_medium=email&utm_term=Article3Button&utm_content=j18&src=Week%2039%20-%20ACSM%20Hot%20Topics%20-%20Sports%20Medicine&et_cid=236215&et_rid=pedronetoribeiro@gmail.com

segunda-feira, 17 de Junho de 2013

Predictors of change differ for moderate and vigorous intensity physical activity and for weekdays and weekends: a longitudinal analysis

Kirsten Corder1,2*, Christopher Craggs1,2, Andrew P Jones1,3, Ulf Ekelund2,4, Simon J Griffin1,2
and Esther MF van Sluijs

Abstract
Background: Predictors of physical activity (PA) change are rarely investigated separately for different PA intensities and
for weekdays/weekends. We investigated whether individual-level predictors of one-year change in objectively-measured
physical activity differ for moderate PA (MPA) and vigorous PA (VPA) and for weekends and weekdays.
Methods: Accelerometer-assessed PA (mins) was obtained at baseline and +1 year (n = 875, 41.5% male, Mean ±
SD baseline age: 9.8 ± 0.4 years-old). Potential predictors (n = 38) were assessed at baseline from psychological
(e.g. self-efficacy), socio-cultural (e.g. parent support) and environmental domains (e.g. land use). Associations between
predictors and change in MPA (2000–3999 counts/minute (cpm)) and VPA (≥4000 cpm) separately for weekdays and
weekends were studied using multi-level linear regression. Analyses were adjusted for school clustering, sex and
baseline PA.
Results: Weekend PA declined (MPA decline 4.6 ± 21.8 mins/day; VPA decline: 2.1 ± 20.1 mins/day; both p < 0.001)
whereas weekday PA did not significantly change. Higher baseline PA and being a girl were associated with greater PA
declines in all four outcomes; remaining predictors differed for MPA and VPA and/or weekdays and weekends. Family
logistic support was associated with less of a decline in weekend MPA (CI 95%) 0.15 (0.05, 0.25) and VPA 0.19 (0.09,
0.29), and peer support with less of a decline in weekday MPA 0.18 (0.02, 0.34) and VPA 0.22 (0.06, 0.38).
Conclusions: Results highlight the relevance of investigating predictors of PA change separately for different PA
intensities and for weekdays/weekends. In addition to continued focus on school PA promotion, more effort to target
interventions during weekends, such as in the family and community appears important. Encouraging peer support to
increase weekday PA and targeting parent support for weekend PA may be health promotion priorities.

http://www.ijbnpa.org/content/pdf/1479-5868-10-69.pdf

Reducing high calorie snack food in young adults: a role for social norms and health based messages

Eric Robinson1,2*, Ellis Harris2
, Jason Thomas2
, Paul Aveyard2,3 and Suzanne Higgs

Abstract
Background: Consumption of high calorie junk foods has increased recently, especially among young adults and
higher intake may cause weight gain. There is a need to develop public health approaches to motivate people to
reduce their intake of junk food.
Objective: To assess the effect of health and social norm messages on high calorie snack food intake (a type of
junk food) as a function of usual intake of junk food.
Design: In a between-subjects design, 129 young adults (45 men and 84 women, mean age = 22.4 years, SD = 4.5)
were assigned to one of three conditions: 1) a social norm condition, in which participants saw a message about
the junk food eating habits of others; 2) a health condition, in which participants saw a message outlining the
health benefits of reducing junk food consumption and; 3) a control condition, in which participants saw a nonfood related message. After exposure to the poster messages, participants consumed a snack and the choice and
amount of snack food consumed was examined covertly. We also examined whether usual intake of junk food
moderated the effect of message type on high calorie snack food intake.
Results: The amount of high calorie snack food consumed was significantly lower in both the health and the social
norm message condition compared with the control message condition (36% and 28%, both p < 0.05). There was
no significant difference in snack food or energy intake between the health and social norm message conditions.
There was no evidence that the effect of the messages depended upon usual consumption of junk food.
Conclusions: Messages about the health effects of junk food and social normative messages about intake of junk
food can motivate people to reduce their consumption of high calorie snack food.

http://www.ijbnpa.org/content/pdf/1479-5868-10-73.pdf

Programming Resistance Training for Clients With Type 2 Diabetes Mellitus

Grabert, Derek MS, CSCS*D; Feito, Yuri PhD, MPH, RCEP, CES


Abstract

IMPLEMENTING A RESISTANCE TRAINING PROGRAM FOR CLIENTS WITH TYPE 2 DIABETES POSES SOME DIFFICULTIES, BUT WITH THE PROPER DESIGN, THESE CLIENTS CAN ATTAIN SIGNIFICANT HEALTH AND FITNESS BENEFITS. RESISTANCE TRAINING PROGRAMS SHOULD BE PROGRESSIVE IN INTENSITY AND INDIVIDUALIZED FOR EACH CLIENT TO IMPROVE GLYCEMIC CONTROL, LEAN BODY MASS, AND STRENGTH

http://journals.lww.com/nsca-scj/Abstract/publishahead/Programming_Resistance_Training_for_Clients_With.99601.aspx

terça-feira, 28 de Maio de 2013

What is EPOC and Why is it Useful for Fat Loss?

Brad Schoenfeld, MS, CSCS, CSPS, NSCA-CPT

http://www.nsca.com/Education/Videos/What-is-EPOC-and-Why-is-it-Useful-for-Fat-Loss/

The Impact of Physical Education on Obesity among Elementary School Children


John Cawley
3M24 Martha Van Rensselaer Hall Cornell University
Ithaca, NY 14853
USA
E-mail:
jhc38@cornell.edu 


John Cawley
Cornell University and IZA
David Frisvold
Emory University
Chad Meyerhoefer
Lehigh University

In response to the dramatic rise in childhood obesity, the Centers for Disease Control (CDC) and other organizations have advocated increasing the time that elementary school children spend in physical education (PE) classes. However, little is known about the effect of PE on child weight. This paper measures that effect by instrumenting for child PE time with state policies, using data from the Early Childhood Longitudinal Study, Kindergarten Cohort (ECLS-K) for 1998-2004. Results from IV models indicate that PE lowers BMI z-score and reduces the probability of obesity among 5th graders (in particular, boys), while the instrument is insufficiently powerful to reliably estimate effects for younger children. This represents some of the first evidence of a causal effect of PE on youth obesity, and thus offers at least some support to the assumptions behind the CDC recommendations. We find no evidence that increased PE time crowds out time in academic courses or has spillovers to achievement test scores. 



http://anon-ftp.iza.org/dp6807.pdf