CRF, MVPA, NEAT, PAEE, and Now Sedentary Time: Will the Pendulum Swing Back Again?
Pedro Hallal and Ulf Ekelund
Bicycling but not Walking Is Independently Associated With Fasting Insulin in Abdominally Obese Women
Erik Hemmingsson, Ulf Ekelund, and Joanna Udden
The impact of walking and bicycling on insulin resistance (IR) in women with abdominal obesity is unclear.
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.
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.
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.
Are Birth Weight, Early Growth, and Motor Development Determinants of Physical Activity in Children and Youth? A Systematic Review and Meta-Analysis
Guro Pauck Øglund, Maria Hildebrand, and Ulf Ekelund
The purpose of this systematic review was to explore whether birth weight, early growth and motor development act as determinants of physical activity in children and youth.
We performed a systematic literature search on the possible early life determinants. A meta-analysis was performed on the association between birthweight and objectively measured physical activity.
We identified 9 studies examining birth weight, in which none of the studies with objectively measured physical activity observed an association between birth weight and physical activity. The meta-analysis confirmed this result (b=-3.08, 95% CI -10.20, 4.04). The 3 studies examining early growth and physical activity in youth differ in methodology and the results are inconsistent. Two studies suggest an association between earlier motor development and physical activity and sport participation in youth. This was not confirmed in a third study.
Our meta-analysis suggests that birth weight is not an important determinant of physical activity in youth. Available data does not allow firm conclusions whether early growth and motor development act as determinants of physical activity in youth.
Assessing Physical Activity among Children with Accelerometers Using Different Time Sampling Intervals and Placements
Andreas Nilsson, Ulf Ekelund, Agneta Yngve, and Michael Söström
The aim was to investigate (a) the effect of five different time sampling intervals (epoch settings) on different intensity levels when assessing physical activity with an accelerometer (CSA, WAM 7164), and (b) whether the placement of the monitor (on the hip and back) would affect the outcome. Sixteen children (aged 7 yrs) were monitored for four consecutive days. A significant main epoch effect was found for time spent at very high (p < .01) and high (p < .01) intensity activities. No significant difference between the two placements regarding total amount of physical activity (cnts • min−1) or different intensity levels was observed. In conclusion, different time sampling intervals, but not placement, should be carefully considered when assessing physical activity.
Validity and Comparability of a Wrist-Worn Accelerometer in Children
Orjan Ekblom, Gisela Nyberg, Elin Ekblom Bak, Ulf Ekelund, and Claude Marcus
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.
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.
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%.
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.
Comparison of Two Methods of Measuring Physical Activity in South African Older Adults
Tracy L. Kolbe-Alexander, Estelle V. Lambert, Judith Biletnikoff Harkins, and Ulf Ekelund
The aim of this study was to assess the validity and reliability of the Yale Physical Activity Survey (YPAS) and the short version of the International Physical Activity Questionnaire (IPAQ) in older South African adults. The YPAS includes measures of weekly energy expenditure (EE) for housework, yard work, caregiving, exercise, and recreation. The IPAQ measures total time and EE during vigorous and moderate activity, walking, and sitting. The instruments were administered twice for test–retest reliability (men, n = 52, 68 ± 5.4 years, and women, n = 70, 66 ± 5.8 years). Data for criterion validity were obtained from accelerometers. YPAS reliability ranged from r = .44 to.80 for men and r = .59 to .99 for women (p < .0001). IPAQ reliability was lower for men (r = .29 to .76) than for women (r = .46 to .77). Criterion validity of the YPAS was .31 to .54 for men and .26 to .29 for women. The YPAS and short IPAQ had comparable results for reliability and criterion validity.
Objective and Self-Reported Physical Activity and Risk of Falling Among Community-Dwelling Older Adults From Southern Brazil
Renata M. Bielemann, Ricardo Oliveira, Andréa Dâmaso Bertoldi, Elaine Tomasi, Flávio Fernando Demarco, Maria Cristina Gonzalez, Andrea Wendt Bohm, Soren Brage, and Ulf Ekelund
This study evaluated prospective associations between self-reported and objectively measured physical activity (PA) and risk of falls among older adults. A cohort study started in 2014 with 1,451 community-dwelling older adults living in Pelotas, Brazil. Leisure-time PA was obtained by the International Physical Activity Questionnaire and 7-day raw accelerometer data evaluated for total, light PA, and moderate to vigorous PA. In 2016–2017, participants recorded their falls in the previous 12 months. Around 23% of the 1,161 participants followed-up in 2016–2017 experienced a fall in the last 12 months. Participants who did not spend any time in self-reported leisure-time PA at baseline had on average 34% higher risk of falls, and individuals in the lowest tertile for moderate to vigorous PA had on average 51% higher risk of falls compared to those in the highest tertile. Low levels of self-reported and objectively measured moderate to vigorous PA were related to higher risk of falling among Brazilian older adults.
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.
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.
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
Prospective studies on physical activity (PA), diet, and body composition in adolescents are lacking, particularly outside high-income countries.
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.
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.
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.
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.