Effects of sitting time associated with media consumption on physical activity patterns and daily energy expenditure of Saudi school students

Background Excessive sitting time is linked to cardiovascular disease morbidity. To date, no studies have accurately measured sitting time patterns in people with stroke. Objective The purpose of this study was to investigate the amount and pattern of accumulation of sitting time, physical activity, and use of time in people with stroke compared with age-matched healthy peers. Design This study used an observational design. Methods Sitting time (total and time accumulated in prolonged, unbroken bouts of ≥30 minutes) was measured with an activity monitor. Physical activity and daily energy expenditure were measured using an accelerometer and a multisensory array armband, respectively. All monitors had a 7-day wear protocol. Participants recalled 1 day of activity (during monitor wear time) using the Multimedia Activity Recall for Children and Adults. Results Sixty-three adults (40 with stroke and 23 age-matched healthy controls) participated. The participants (35% female, 65% male) had a mean age of 68.4 years (SD=10.0). Participants with stroke spent significantly more time sitting (X̅=10.9 h/d, SD=2.0) compared with controls (X̅=8.2 h/d, SD=2.0), with much of this sitting time prolonged (stroke group: X̅=7.4 h/d, SD=2.8; control group: X̅=3.7 h/d, SD=1.7). Participants with stroke accumulated most of their sitting time while watching television and in general quiet time, whereas control participants spent more time reading and on the computer. Physical activity and daily energy expenditure were lower in the stroke group compared with the control group. Limitations A sample of convenience was used to select participants for the stroke and control groups, which may reduce the generalizability of results. Conclusions Participants with stroke spent more time sitting and less time in activity than their age-matched peers. Further work is needed to determine whether reducing sitting time is feasible and leads to clinically important reductions in cardiovascular risk in this population.

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Impacts of vigorous and non-vigorous activity on daily energy expenditure

Proceedings of The Nutrition Society ◽

10.1079/pns2003279 ◽

2003 ◽

Vol 62 (3) ◽

pp. 645-650 ◽

Cited By ~ 44

Author(s):

Klaas R. Westerterp

Keyword(s):

Physical Activity ◽

Body Size ◽

Energy Expenditure ◽

Exercise Training ◽

Physical Activity Level ◽

High Intensity ◽

Activity Level ◽

Daily Energy Expenditure ◽

Activity Intensity ◽

Daily Energy

Activity intensity is a potential determinant of activity-induced energy expenditure. Tri-axial accelerometery is the most objective measurement technique for the assessment of activity intensity, in combination with doubly-labelled water for the measurement of energy expenditure under free-living conditions. Data on the effects of subject characteristics, including body size and age, and exercise training on the relationship between activity intensity and daily energy expenditure are reviewed. Average daily metabolic rate and non-basal energy expenditure are positively related to body size. The duration and intensity of physical activities do not need to be equivalent to the energy spent on activity. Obese subjects spend more energy on physical activity but can perform fewer activities, especially high-intensity (weight-bearing) activities, because of their higher body weight. Physical activity generally declines gradually from about 60 years of age onwards. Most subjects >80 years have an activity level well below the level defined for sedentary middle-aged adults. Spending relatively more time on low-intensity activities has a negative effect on the mean physical activity level. To obtain a higher physical activity level does not necessarily imply high-intensity activities. In an average subject 25% of the activity-induced energy expenditure may be attributed to high-intensity activities. Exercise training, as a form of high-intensity activity, affects the physical activity level more in younger subjects than in elderly subjects.

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