| 1. |
- Craig, Cora L, et al.
(författare)
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International physical activity questionnaire : 12-country reliability and validity
- 2003
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Ingår i: Medicine & Science in Sports & Exercise. - 0195-9131 .- 1530-0315. ; 35:8, s. 1381-1395
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Physical inactivity is a global concern, but diverse physical activity measures in use prevent international comparisons. The International Physical Activity Questionnaire (IPAQ) was developed as an instrument for cross-national monitoring of physical activity and inactivity.METHODS: Between 1997 and 1998, an International Consensus Group developed four long and four short forms of the IPAQ instruments (administered by telephone interview or self-administration, with two alternate reference periods, either the "last 7 d" or a "usual week" of recalled physical activity). During 2000, 14 centers from 12 countries collected reliability and/or validity data on at least two of the eight IPAQ instruments. Test-retest repeatability was assessed within the same week. Concurrent (inter-method) validity was assessed at the same administration, and criterion IPAQ validity was assessed against the CSA (now MTI) accelerometer. Spearman's correlation coefficients are reported, based on the total reported physical activity.RESULTS: Overall, the IPAQ questionnaires produced repeatable data (Spearman's rho clustered around 0.8), with comparable data from short and long forms. Criterion validity had a median rho of about 0.30, which was comparable to most other self-report validation studies. The "usual week" and "last 7 d" reference periods performed similarly, and the reliability of telephone administration was similar to the self-administered mode.CONCLUSIONS: The IPAQ instruments have acceptable measurement properties, at least as good as other established self-reports. Considering the diverse samples in this study, IPAQ has reasonable measurement properties for monitoring population levels of physical activity among 18- to 65-yr-old adults in diverse settings. The short IPAQ form "last 7 d recall" is recommended for national monitoring and the long form for research requiring more detailed assessment.
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| 2. |
- Ekelund, Ulf
(författare)
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Assessment of physical activity and energy expenditure in adolescents
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Physical activity (PA) is a complex, multidimensional human behaviour that includes all bodily movement from fidgeting to participation in marathon running. The detailed relationship (i.e. dose - response) between the type and degree of PA and its effects on various aspects of health remains to be elucidated, not least in young people. The development and evaluation of different PA assessment methods is therefore of high priority. Methods of physical activity assessment include both self-report methods, such as activity diaries, questionnaires and activity recalls, and objective assessment techniques. Objective assessment of free-living physical activity can be based on physiological (energy expenditure, heart rate [HR] monitoring) and biomechanical (accelerometry) principles. The overall purpose with the present studies was to increase our understanding of the suitability of different PA assessment methods for use in normally active adolescents m young athletes, and to gain further knowledge about the amount and pattern of physical activity among adolescents. One hundred and fifty-seven randomly selected boys and girls and eight volunteer young athletes participated in the studies. One self-report method (activity diary) and three objective methods (HR monitoring, accelerometry and the doubly labelled water method, [DLW] were applied in the studies. All measurements of PA and total energy expenditure (TEE) were performed under free-living conditions. In addition, the relationship between HR and energy expenditure was individually measured during rest and standardised exercises in the laboratory. In the group of eight young athletes all measurements were performed under two different training conditions. The main findings were that: 1) there was no significant difference for the data on TEE and time spent at PA of moderate intensity or higher between the HR monitoring method and the activity diary; 2) the fitness level of the subjects affected the use of absolute HR when defining PA intensity levels; 3) in a random sample of 14-to-15-year-old adolescents, approximately 30% of the boys and girls did not achieve appropriate levels of PA according to published recommendations; and 4) the relationship between TEE and its derivatives measured by DLW, on the one hand, and the total amount of physical activity measured with an accelerometer, on the other, was influenced by the different training condition, whereas TEE estimated by minute-by-minute HR monitoring seem to be unaffected both by the definition of the FLEX HR and by the training condition. It is concluded that the activity diary method is a valid method for estimating TEE and time spent at PA of moderate intensity or higher in groups of adolescents. With the HR monitoring method, use of absolute heart rates for defining intensity levels reduces the validity of the data interpretation. Individual calibration for the heart rate - oxygen uptake relationship is therefore necessary. A relatively large group of adolescents does not achieve the amounts of physical activity recommended beneficial for health. This seems to be a public health concern. The HR monitoring method is not affected by different training regimens and is therefore a more favourable way of assessing physical activity in young athletes as compared to accelerometry.
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| 3. |
- Ekelund, Ulf, 1960-, et al.
(författare)
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Body movement and physical activity energy expenditure in children and adolescents : how to adjust for differences in body size and age
- 2004
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 79:5, s. 851-856
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Physical activity data in children and adolescents who differ in body size and age are influenced by whether physical activity is expressed in terms of body movement or energy expenditure.OBJECTIVE: We examined whether physical activity expressed as body movement (ie, accelerometer counts) differs from physical activity energy expenditure (PAEE) as a function of body size and age.DESIGN: This was a cross-sectional study in children [n = 26; (+/-SD) age: 9.6 +/- 0.3 y] and adolescents (n = 25; age: 17.6 +/- 1.5 y) in which body movement and total energy expenditure (TEE) were simultaneously measured with the use of accelerometry and the doubly labeled water method, respectively. PAEE was expressed as 1) unadjusted PAEE [TEE minus resting energy expenditure (REE); in MJ/d], 2) PAEE adjusted for body weight (BW) (PAEE. kg(-1). d(-1)), 3) PAEE adjusted for fat-free mass (FFM) (PAEE. kg FFM(-1). d(-1)), and 4) the physical activity level (PAL = TEE/REE).RESULTS: Body movement was significantly higher (P = 0.03) in children than in adolescents. Similarly, when PAEE was normalized for differences in BW or FFM, it was significantly higher in children than in adolescents (P = 0.03). In contrast, unadjusted PAEE and PAL were significantly higher in adolescents (P < 0.01).CONCLUSIONS: PAEE should be normalized for BW or FFM for comparison of physical activity between children and adolescents who differ in body size and age. Adjusting PAEE for FFM removes the confounding effect of sex, and therefore FFM may be the most appropriate body-composition variable for normalization of PAEE. Unadjusted PAEE and PAL depend on body size.
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| 4. |
- Ekelund, Ulf, et al.
(författare)
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Energiförbrukning och fysisk aktivitet bland unga elitidrottare : en tillämpning av kontinuerlig hjärtfrekvensregistrering
- 2001
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Ingår i: Svensk Idrottsforskning. - 1103-4629. ; 10:2, s. 29-33
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Tidskriftsartikel (refereegranskat)abstract
- Att med noggrannhet mäta fysisk aktivitet och total energiförbrukning utanför laboratoriet och över flera dygn har länge ansetts som komplicerat. Det finns emellertid idag metoder som möjliggör noggranna mätningar av fysisk aktivitet och total energiförbrukning utanför laboratoriet och över flera dygn. Det förefaller därför troligt att vi inom en snar framtid kommer att ha mer och bättre information om energiförbrukning och variationer i energiförbrukning under olika typer av träning bland idrottsmän. Än återstår dock att närmare lära känna dessa metoder. I det följande redovisar vi några resultat från en studie av skridskoåkare, i vilken dessa metoder tillämpats och testats.
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| 5. |
- Ekelund, Ulf, 1960-, et al.
(författare)
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Energy expenditure assessed by heart rate and doubly labeled water in young athletes
- 2002
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Ingår i: Medicine & Science in Sports & Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131 .- 1530-0315. ; 34:8, s. 1360-1366
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To compare total energy expenditure (TEE) estimated by the FLEX heart rate (HR) method with that measured by the doubly labeled water (DLW) technique in young speed skaters. We hypothesized that the accuracy of FLEX HR-estimated TEE would be affected by a) the definition of the FLEX HR and b) the type of training regimen.METHODS: Eight young athletes (mean age 18.2 +/- 1.3 yr) underwent measurements during two 10-d training periods: an off-season period with voluntary training (predominantly running) and a preseason period mainly focused on skating technique training. TEE was measured simultaneously by the DLW and FLEX HR methods. FLEX HR1 was defined as the mean of the HRs during all resting calibration activities and the lowest HR during exercising calibration activities. FLEX HR2 was defined as the mean of the highest HR during resting activities and the lowest HR during exercising.RESULTS: ANOVA showed that FLEX HR1 was significantly lower than FLEX HR2 (mean of both periods; 77 +/- 5 vs 84 +/- 6 beats.min(-1); P = 0.004). TEE values obtained by DLW were 16.8 +/- 3.8 and 16.9 +/- 2.9 MJ.d(-1) in the two periods, respectively. TEE values calculated from FLEX HR1 were 17.8 +/- 3.6 and 17.4 +/- 2.6 MJ.d(-1), and those from FLEX HR2 17.1 +/- 3.1 and 17.0 +/- 2.7 MJ.d-1, respectively. No significant period (P = 0.83) or method (P = 0.44) effect on TEE was observed.CONCLUSION: FLEX HR-estimated TEE was not affected by the definition of the FLEX HR or by the type of training regimen as compared with TEE measured by the DLW method in young athletes.
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| 6. |
- Ekelund, Ulf, 1960-, et al.
(författare)
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Field evaluation of the Computer Science and Application's Inc. Activity monitor during running and skating training in adolescent athletes
- 2000
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Ingår i: International Journal of Sports Medicine. - : Georg Thieme Verlag KG. - 0172-4622 .- 1439-3964. ; 21:8, s. 586-592
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the validity of the CSA activity monitor for assessment of the total amount of physical activity in adolescent athletes. Activity data were compared to data on daily energy expenditure and its derivatives measured by the doubly labeled water method. Seven athletes (speed skaters) with a mean age of 18.2+/-1.1 y were monitored twice (off-season and pre-season) by the activity monitor for eight consecutive days. The primary training during the off-season period was running whereas the pre-season period mainly involved skate training (i.e. inline skating, slideboard training, and skating imitations). Activity counts were significantly correlated to all energy estimates during the off-season period (r=0.93-0.96; P<0.01) whereas not during the pre-season period (r=0.32-0.57). A two-way multivariate analysis of variance showed a significant period effect for activity counts (668+/-163 vs. 548+/-91; P=0.026) whereas not for total daily energy expenditure (15.7+/-2.1 MJ x d(-1) vs. 16.0+/-1.0 MJ x d(-1); P=0.71). The relationship between activity counts and total daily energy expenditure seems to be affected by different training conditions. Therefore these circumstances have to be carefully considered in the interpretation of activity monitor data.
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| 7. |
- Ekelund, Ulf, 1960-, et al.
(författare)
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Heart rate as an indicator of the intensity of physical activity in human adolescents
- 2001
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 85:3-4, s. 244-249
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were, in a group of adolescents, firstly to identify the absolute heart rates (HR) and the percentages of maximal heart rates (HRmax) corresponding to 40%, 60% and 80% of peak oxygen uptake (PVO2), secondly to identify absolute and relative (%PVO2) oxygen uptakes (VO2) corresponding to HR of 120, 140 and 160 beats.min-1, and thirdly to examine a possible effect of fatness and fitness on the relationship between HR and VO2. The subjects were 127 (60 boys, 67 girls) adolescents with a mean age of 14.8 (SD 0.3) years. The HR and VO2 were measured by means of an incremental exercise test to exhaustion. Linear regressions were performed for the HR-VO2 and VO2-HR relationships using absolute and relative (%HRmax, %PVO2) data for each individual. From these regressions, target HR and VO2 were computed. Average target HR corresponding to 40%, 60% and 80% of PVO2 were: 119 (SD 9), 145 (SD 9), 171 (SD 8), and 120 (SD 10), 146 (SD 8), 172 (SD 8) beats.min-1 for boys and girls, respectively. Average VO2 corresponding to HR of 120, 140 and 160 beats.min-1 were: 22 (SD 5), 30 (SD 5), 38 (SD 6) and 18 (SD 4), 24 (SD 4), 31 (SD 4) mlO2.kg-1.min-1 for boys and girls, respectively. An analysis of covariance showed a significant fitness effect (P < 0.001) for predicted VO2 at all HR studied. The results suggest that the use of absolute HR to define exercise intensity levels when assessing young people's physical activity using HR monitoring detracts from the validity of the interpretation of the data.
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| 8. |
- Ekelund, Ulf, et al.
(författare)
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Patients with suspected acute coronary syndrome in a university hospital emergency department: an observational study.
- 2002
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Ingår i: BMC Emergency Medicine. - 1471-227X. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Improved diagnostics in suspected acute coronary syndrome (ACS) are considered to be needed. To help clarify the current situation and the improvement potential, judged risk in the emergency department (ED) and outcome were analyzed among patients with suspected ACS at a university hospital. Methods: 157 consecutive patients with symptoms of ACS were included at the ED during 10 days. Risk of ACS was estimated in the ED for each patient based on history, physical examination and ECG by assigning them to one of four risk categories; I (obvious myocardial infarction, MI), II (strong suspicion of ACS), III (vague suspicion of ACS), and IV (no suspicion of ACS). Results: 4, 17, 29 and 50% of the patients were allocated to risk categories I-IV respectively. 74 patients (47%) were hospitalized but only 19 (26%) had ACS as the discharge diagnose. In risk categories I-IV, ACS rates were 100, 37, 12 and 0%, respectively. Of those admitted without ACS, at least 37% could probably, given perfect ED diagnostics, have been immediately discharged. 83 patients were discharged from the ED, and among them there were no hospitalizations for ACS or cardiac mortality at 6 months. Only about three patients per 24 h were considered eligible for a potential ED chest pain unit. Conclusions: Almost 75% of the patients hospitalized with suspected ACS did not have it, and some 40% of these patients could probably, given perfect immediate diagnostics, have been managed as outpatients. The potential for diagnostic improvement in the ED seems large.
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| 9. |
- Ekelund, Ulf, 1960-, et al.
(författare)
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Physical activity assessed by activity monitor and doubly labeled water in children
- 2001
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Ingår i: Medicine & Science in Sports & Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131 .- 1530-0315. ; 33:2, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To validate the Computer Science and Application's (CSA) activity monitor for assessment of the total amount of physical activity during two school-weeks in 9-yr-old children and to develop equations to predict total energy expenditure (TEE) and activity energy expenditure (AEE) from activity counts and anthropometric variables.METHODS: A total of 26 children (15 boys and 11 girls, mean age 9.1 +/- 0.3 yr) were monitored for 14 consecutive days. TEE was simultaneously measured by the doubly labeled water method. Averaged activity counts (counts.min(-1)) were compared with data on: 1) TEE, 2) AEE = TEE minus basal metabolic rate (BMR; estimated from predictive equations), and 3) daily physical activity level (PAL = TEE/BMR).RESULTS: Physical activity determined by activity counts was significantly related to the data on energy expenditures: TEE (r = 0.39; P < 0.05), AEE (r = 0.54; P < 0.01), and PAL (r = 0.58; P < 0.01). Multiple stepwise regression analysis showed that TEE was significantly influenced by gender, body composition (body weight or fat free mass), and activity counts (R(2) = 0.54--0.60). AEE was significantly influenced by activity counts and gender (R(2) = 0.45). There were no significant differences between activity counts and PAL in discriminating among activity levels with "low" (PAL < 1.56), "moderate" (1.57 < or = PAL > or = 1.81), and "high" (PAL > 1.81) intensity.CONCLUSION: Activity counts from the CSA activity monitor seems to be a useful measure of the total amount of physical activity in 9-yr-old children. Activity counts contributed significantly to the explained variation in TEE and was the best predictor of AEE.
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| 10. |
- Ekelund, Ulf, 1960-, et al.
(författare)
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Physical activity but not energy expenditure is reduced in obese adolescents : a case-control study
- 2002
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 76:5, s. 935-941
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The influence of physical activity on body weight in children and adolescents is controversial.OBJECTIVE: The objective was to test the hypothesis that the intensity and duration of physical activity differ between obese and normal-weight adolescents, with no difference in estimated energy expenditure.DESIGN: We compared physical activity in 18 (8 males, 10 females) obese [body mass index (in kg/m(2)) > 30] adolescents (14-19 y) with that in a matched, normal-weight (BMI < 27) control group. Total energy expenditure (TEE) was measured with the doubly labeled water method, and physical activity was measured simultaneously by accelerometry. The physical activity level was determined as the ratio of TEE to the resting metabolic rate (RMR) and activity energy expenditure as 0.9 TEE minus RMR. Accelerometry data included total physical activity (counts x min(-1) x d(-1)), accumulated and continuous duration of activity, and continuous 10-min periods of physical activity of moderate intensity.RESULTS: There was no significant difference in adjusted (analysis of covariance) TEE, RMR, or AEE between groups. The physical activity level was significantly lower (P < 0.05) in the obese group. No sex x group interaction was observed. Differences in total physical activity (P < 0.001), accumulated time (P < 0.05), continuous time (P < 0.01), and continuous 10-min periods of physical activity of moderate intensity (P < 0.01) were observed between groups.CONCLUSIONS: Obese adolescents are less physically active than are normal-weight adolescents, but physical activity-related energy expenditure is not significantly different between groups. The data suggest that physical activity is not necessarily equivalent to the energy costs of activity.
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