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CRF, MVPA, NEAT, PAEE, and Now Sedentary Time: Will the Pendulum Swing Back Again?

Pedro Hallal and Ulf Ekelund

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Bicycling but not Walking Is Independently Associated With Fasting Insulin in Abdominally Obese Women

Erik Hemmingsson, Ulf Ekelund, and Joanna Udden

Background:

The impact of walking and bicycling on insulin resistance (IR) in women with abdominal obesity is unclear.

Methods:

Pooled analysis of data from a randomized trial on physically active commuting (bicycling + walking vs walking only) in women with abdominal obesity [n = 98; age:47.3 ± 7.6 yrs; waist circumference (WC):103.1 ± 7.8 cm]. Bicycling and walking data were collected during 7 consecutive days by trip meters (Trelock FC-410) and pedometers (Yamax digiwalker SW-200) at baseline, 2, 4, and 6 months. Owing to a skew distribution we analyzed bicycling as a binary dummy variable with a 10 km/week cut-off. Fasting serum insulin and homeostatic model assessment – insulin resistance (HOMA-IR) were assessed at baseline and 6 months, as were body mass index (BMI), WC, and dual x-ray absorptiometry (DXA)-assessed % whole-body fat.

Results:

Increased bicycling by 10 km/wk was associated with reductions in fasting serum insulin at follow-up independent of age, treatment allocation, baseline phenotype, Δ walking, and Δ % body fat (β = −10.9, P = .042), but not HOMA-IR (β = −2.0, P = .13). Increased walking was not associated with fasting serum insulin (P = .33) or HOMA-IR (P = .44) at follow-up, after adjustment for the same covariates and Δ bicycling.

Conclusion:

Increased bicycling but not walking was associated with reduced insulin levels at follow-up. Bicycling may be more effective than walking for reducing insulin levels in abdominally obese women.

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Validity and Comparability of a Wrist-Worn Accelerometer in Children

Orjan Ekblom, Gisela Nyberg, Elin Ekblom Bak, Ulf Ekelund, and Claude Marcus

Background:

Wrist-worn accelerometers may provide an alternative to hip-worn monitors for assessing physical activity as they are easier to wear and may thus facilitate long-term recordings. The current study aimed at a) assessing the validity of the Actiwatch (wrist-worn) for estimating energy expenditure, b) determining cut-off values for light, moderate, and vigorous activities, c) studying the comparability between the Actiwatch and the Actigraph (hip-worn), and d) assessing reliability.

Methods:

For validity, indirect calorimetry was used as criterion measure. ROC-analyses were applied to identify cut-off values. Comparability was tested by simultaneously wearing of the 2 accelerometers during free-living condition. Reliability was tested in a mechanical shaker.

Results:

All-over correlation between accelerometer output and energy expenditure were found to be 0.80 (P < .001).Based on ROC-analysis, cut-off values for 1.5, 3, and 6 METs were found to be 80, 262, and 406 counts per 15 s, respectively. Energy expenditure estimates differed between the Actiwatch and the Actigraph (P < .05). The intra- and interinstrument coefficient of variation of the Actiwatch ranged between 0.72% and 8.4%.

Conclusion:

The wrist-worn Actiwatch appears to be valid and reliable for estimating energy expenditure and physical activity intensity in children aged 8 to 10 years.

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Long-Term Correlates of Objectively Measured Physical Activity and Sedentary Time in Norwegian Men and Women

Ane Kristiansen Solbraa, Ulf Ekelund, Ingar M. Holme, Sidsel Graff-Iversen, Jostein Steene-Johannessen, Eivind Aadland, and Sigmund Alfred Anderssen

Background:

Sex, age, body mass index (BMI), perceived health and health behavior are correlates known to affect physical activity and sedentary time. However, studies have often been cross-sectional, and less is known about long-term correlates. Thus, the aims were to investigate 1) the associations between a set of characteristics (demographic, biological, psychological, and behavioral) and objectively measured physical activity and sedentary time at 13-year follow-up, and 2) the association between changes in these characteristics over time and physical activity and sedentary time.

Methods:

Baseline characteristics were collected in 40-year-olds in 1996, and follow-up data on objectively measured physical activity and sedentary time were obtained in 2009 (n = 240). Data were analyzed by multiple linear regressions.

Results:

Self-reported physical activity (P < .001) and improved perceived health (P = .046) were positively associated with moderate-to-vigorous physical activity (MVPA) whereas BMI (P = .034) and increased BMI (P = .014) were negatively associated with MVPA at follow-up. Women spent less time being sedentary than men (P = .019). Education (P < .001) was positively associated and improved perceived health (P = .010) was negatively associated with sedentary time at follow-up.

Conclusions:

MVPA and sedentary time at follow-up were associated with behavioral, biological and demographic correlates. However, the nature of our analyses prevents us from inferring causality.

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Physical Activity and Safety From Crime Among Adults: A Systematic Review

Inacio C. M. da Silva, Valerie L. C. Payne, Adriano Akira Hino, Andrea Ramirez Varela, Rodrigo S. Reis, Ulf Ekelund, and Pedro C. Hallal

Background:

The aim of this study was to review the evidence to date on the association between physical activity and safety from crime.

Methods:

Articles with adult populations of 500+ participants investigating the association between physical activity and safety from crime were included. A methodological quality assessment was conducted using an adapted version of the Downs and Black checklist.

Results:

The literature search identified 15,864 articles. After assessment of titles, abstracts and full-texts, 89 articles were included. Most articles (84.3%) were derived from high-income countries and only 3 prospective articles were identified. Articles presented high methodological quality. In 38 articles (42.7%), at least one statistically significant association in the expected direction was reported (ie, safety from crime was positively associated with physical activity). Nine articles (10.1%) found an association in the unexpected direction and 42 (47.2%) did not find statistically significant associations. The results did not change when we analyzed articles separately by sex, age, type of measurement, or domains of physical activity evaluated.

Conclusions:

The current evidence, mostly based on cross-sectional studies, suggests a lack of association between physical activity and safety from crime. Prospective studies and natural experiments are needed, particularly in areas with wide crime variability.

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A Methodological Model for Collecting High-Quality Data on Physical Activity in Developing Settings—The Experience of the 1993 Pelotas (Brazil) Birth Cohort Study

Felipe Fossati Reichert, Ana Maria Batista Menezes, Jonathan Charles Kingdom Wells, Ulf Ekelund, Fabiane Machado Rodrigues, and Pedro Curi Hallal

Background:

Prospective studies on physical activity (PA), diet, and body composition in adolescents are lacking, particularly outside high-income countries.

Goals:

To describe the methods used to assess these variables in the 1993 Pelotas (Brazil) Birth Cohort and to discuss the fieldwork challenges faced and alternatives to overcome them.

Methods:

In 2006–07 a subsample of the 1993 Pelotas cohort was revisited. PA was estimated using questionnaires, a combined heart-rate and motion sensor (Acti-Heart), and the ActiGraph GT1M accelerometer. Diet was investigated by questionnaire. Total body water was determined by stable isotopes. Thirty individuals had their total energy expenditure assessed by doubly labeled water. All data were collected at participants’ home.

Results:

The logistics of the fieldwork and the difficulties in undertaking the study and alternatives to overcome them are presented. Preliminary analyses show that 511 individuals were traced (response rate = 90.0%). Compliance of both adolescents and their families for the motion sensors and body-composition measurements was excellent.

Conclusions:

The authors conclude that it is feasible to carry out high-quality studies on PA in developing countries. They hope the article will be useful to other researchers interested in carrying out similar studies.

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Trajectories of Device-Measured Physical Activity During Early Childhood and Its Determinants: Findings From the 2015 Pelotas (Brazil) Birth Cohort Study

Debora Tornquist, Inácio Crochemore-Silva, Luciana Tornquist, Grégore I. Mielke, Ulf Ekelund, Joseph Murray, and Marlos R. Domingues

Background: The objective was to describe trajectories of physical activity (PA) measured by accelerometry during early childhood and to test associations with sociodemographic, gestational, maternal, and perinatal determinants. Methods: Data from 1798 children from the 2015 Pelotas (Brazil) Birth Cohort were analyzed. PA was measured with wrist accelerometers at 1, 2, and 4 years. PA trajectories were estimated using group-based trajectory modeling, and associations with determinants were tested using Poisson regression with robust variance. Results: Two trajectories were identified: Moderate and high PA, both showing a linear increase in PA in the first years but differing in volume. Girls (prevalence ratio [PR]: 0.91; 95% confidence interval [CI], 0.88–0.94), highly educated mothers (PR: 0.93; 95% CI, 0.88–0.97), and high birth weight children (PR: 0.91; 95% CI, 0.85–0.97) showed less probability of high PA trajectory. Birth order ≥3 (PR: 1.06; 95% CI, 1.01–1.11) was associated with higher likelihood of high PA trajectory. Conclusions: Children showed an increase in PA during the first years, with 2 trajectories that differ in PA levels. Female sex, high maternal schooling, and high birth weight reduced the probability of having a high PA trajectory, while higher birth order increased this probability. These characteristics should be considered when planning PA interventions for children in early childhood.

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Objectively Measured Physical Activity and Polypharmacy Among Brazilian Community-Dwelling Older Adults

Renata M. Bielemann, Marysabel P.T. Silveira, Bárbara H. Lutz, Vanessa I.A. Miranda, Maria Cristina Gonzalez, Soren Brage, Ulf Ekelund, and Andréa Dâmaso Bertoldi

Background: Previous observations regarding association between physical activity (PA) and use of medicines among older adults are derived from self-reported PA. This study aimed to evaluate the association between objectively measured PA and polypharmacy among older adults with multimorbidity in Southern Brazil. Methods: This study included 875 noninstitutionalized older people, aged ≥60 years. Prescribed medicines used in the 15 days prior to the interview, socioeconomic data, and the presence of comorbidities were self-reported. Accelerometers were used to evaluate PA following the interview. Results: Prevalence of polypharmacy (≥5 medicines) was 38.3% (95% confidence interval, 35.0–41.5); those belonging to the lowest tertile of PA used more medicines. The authors observed a significant inverse association for polypharmacy between men belonging to the second and third tertiles of PA for objectively measured overall PA and light PA compared with the most inactive tertile. For women, the association between PA and polypharmacy was significant for overall, light, and moderate to vigorous PA only in the third tertile. Conclusions: Overall, light and moderate to vigorous PA were inversely associated to polypharmacy and differed by gender. Promotion of PA in older adults may be an effective intervention to reduce the number of medicines used independent of the number of comorbidities.

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Prospective Associations Between Physical Activity Level and Body Composition in Adolescence: 1993 Pelotas (Brazil) Birth Cohort

Felipe Fossati Reichert, Jonathan Charles Kingdom Wells, Ulf Ekelund, Ana Maria Baptista Menezes, Cesar Gomes Victora, and Pedro C. Hallal

Background:

Physical activity may influence both fat and lean body mass. This study investigated the association between physical activity in children between the ages of 11 and 13 years and both fat and lean mass.

Methods:

A subsample of the 1993 Pelotas (Brazil) Birth Cohort was visited in 2004–2005 and 2006–2007. Physical activity was estimated through standardized questionnaires. Body composition (ie, fat and lean mass) was measured using deuterium dilution. Those with moderate-to-vigorous activity greater than 420 min/wk were classified as active, and physical activity trajectory was defined as being above or below the cutoff at each visit.

Results:

Four hundred eighty-eight adolescents (51.8% boys) were evaluated. The mean difference in fat mass in boys and girls who reported ≥ 420 min/wk of physical activity in both visits compared with those who were consistently inactive was –4.8 kg (P ≤ .001). There was an inverse association between physical activity and fat mass among boys in both crude and confounder-adjusted analyses, whereas for girls, the association was evident only in the crude analysis. There was no significant association between physical activity and lean mass.

Conclusion:

Physical activity may contribute to tackling the growing epidemic of adolescent obesity in low- and middle-income countries.

Open access

Predictive Validity of a Thigh-Worn Accelerometer METs Algorithm in 5- to 12-Year-old Children

Christiana M.T. van Loo, Anthony D. Okely, Marijka Batterham, Tina Hinkley, Ulf Ekelund, Soren Brage, John J. Reilly, Gregory E. Peoples, Rachel Jones, Xanne Janssen, and Dylan P. Cliff

Background:

To validate the activPAL3 algorithm for predicting metabolic equivalents (TAMETs) and classifying MVPA in 5- to 12-year-old children.

Methods:

Fifty-seven children (9.2 ± 2.3y, 49.1% boys) completed 14 activities including sedentary behaviors (SB), light (LPA) and moderate-to-vigorous physical activities (MVPA). Indirect calorimetry (IC) was used as the criterion measure. Analyses included equivalence testing, Bland-Altman procedures and area under the receiver operating curve (ROC-AUC).

Results:

At the group level, TAMETs were significantly equivalent to IC for handheld e-game, writing/coloring, and standing class activity (P < .05). Overall, TAMETs were overestimated for SB (7.9 ± 6.7%) and LPA (1.9 ± 20.2%) and underestimated for MVPA (27.7 ± 26.6%); however, classification accuracy of MVPA was good (ROC-AUC = 0.86). Limits of agreement were wide for all activities, indicating large individual error (SB: −27.6% to 44.7%; LPA: −47.1% to 51.0%; MVPA: −88.8% to 33.9%).

Conclusions:

TAMETs were accurate for some SB and standing, but were overestimated for overall SB and LPA, and underestimated for MVPA. Accuracy for classifying MVPA was, however, acceptable.