A 7-day activity diary for assessment of daily energy expenditure validated by the doubly labelled water method in adolescents

The effects of a nutritional intervention on the sports nutrition knowledge and nutritional status of track and field athletes: protocol for a randomized controlled trial

BACKGROUND

Sports nutrition plays a crucial role in providing the fuel to meet the energy demands of athletes' training programmes, enhancing adaptations associated with training, and ensuring rapid recovery between workouts. However, evidence suggests that the dietary habits of many athletes are unsatisfactory when compared to sport-specific nutrition recommendations. This discrepancy is mainly due to a lack of up-to-date, evidence-based nutritional knowledge. Hence, this parallel-group, randomized controlled clinical trial aims to evaluate the effectiveness of a 16-week evidence-based, culturally appropriate, personalized sports nutrition intervention on the sports nutrition knowledge and nutritional status of track and field athletes in Sri Lanka, in comparison to a control group that does not receive this intervention.

METHODS

Elite and highly trained track and field athletes, competing at the national level and/or representing Sri Lanka in international competitions, will be randomly allocated to either the intervention group (IG) (n = 15) or the control group (CG) (n = 15). Participants in the IG will receive an evidence-based, culturally acceptable, personalized sports nutrition intervention from the principal investigator through one-to-one consultations at three-time points (zeroth, fourth, and eighth weeks), while participants in the CG will be followed up throughout the period without receiving the intervention. The primary outcome measure is the number of participants who achieve at least a 10% increase in mean sports nutrition knowledge (SNK) score at the end of the 16th week, compared to the CG. Secondary outcomes include nutrition status and sports performance-related measures at the beginning and end of the intervention.

DISCUSSION

While the primary objective is to enhance SNK, it is anticipated that improvements in nutritional status and overall health may significantly impact sports performance and career longevity of the athletes.

TRIAL REGISTRATION

Sri Lanka Clinical Trials Registry, SLCTR/2024/013. Registered on 10th April 2024. Universal Trial Number (UTN), U1111-1304-8890.

Mechanical efficiency: associations with body composition and glycemic profile in healthy adults

The aim of this study was to assess the association between net mechanical efficiency (NME) and body composition and glycemic profile, in middle-aged (38.3 ± 14.3 years) participants from the Quebec Family Study (QFS). Analyses were completed on a sample of 605 participants (271 males and 334 females) who performed a submaximal exercise test on an ergometer consisting of three consecutive 6-min workloads at increasing intensity during which respiratory gas exchange was assessed. The calculation of NME [power output/ (vO2-vO2seated before exercise)] was based on the values of the last 3 min of the first workload at a targeted power output of 30 W. Correlations between NME and dependent variables were computed separately in males and females. Associations between NME and body composition and glucose-insulin variables were assessed by comparing groups of subjects categorized in sex-specific tertiles of NME after adjustments for age. Significant negative correlations were observed between NME and body composition and glycemic profile in both sexes. Comparison across tertiles showed that individuals with high NME displayed more favorable adiposity and glycemic profiles. These differences remained significant after further adjustments for participation in vigorous physical activity, cardiorespiratory fitness, and mean exercise respiratory exchange ratio whereas most differences in glucose-insulin variables became non-significant after further adjustment for percent body fat. QFS familial data indicate that the heritability of NME reaches about 30%. In conclusion, the results of this study show that beyond aerobic fitness and physical activity-participation, mechanical efficiency is an additional activity-related variable that is independently associated with variations in body composition and glycemic profile.

Comparison of energy requirement estimation using activity record or accelerometer with doubly labeled water method in collegiate male sprinters

BACKGROUND & AIMS

Track and field sprinters must obtain an optimal body composition to improve sprint performance. To successfully change body composition, it is important to evaluate the estimated energy requirements (EER) and fluctuations in total energy expenditure (TEE). However, methods to accurately evaluate the EER and TEE in sprinters have not been fully investigated. The aim of this study was to compare currently used methods with the doubly labeled water (DLW) method, which is currently the gold standard for evaluating EER and TEE.

METHODS

Ten male collegiate sprinters participated in the study. We evaluated TEEDLW and compared it with the EER calculated using two equations used by the National Institute of Health and Nutrition (NIHN) and the Japan Institute of Sports Sciences (JISS). In addition, we evaluated the TEE from the activity record (AR) and triaxial accelerometer (ACC).

RESULTS

TEEDLW (3172 ± 415 kcal/day) was not significantly different from EERNIHN (p = 0.076) or EERJISS (p = 0.967). In addition, there were no significant differences between TEEDLW and TEEAR (p = 0.218). However, two accelerometer-derived equations used to evaluate TEE were found to have underestimated (2783 ± 377 kcal/day, p < 0.001) and overestimated (3405 ± 369 kcal/day, p = 0.009) the TEE.

CONCLUSION

Our results suggest that EERNIHN and EERJISS may be useful in evaluating the EER of collegiate male sprinters on a group basis, and AR may be more accurate than ACC in evaluating the TEE. These results may be helpful when considering nutritional support for male collegiate sprinters.

Physical Activity Levels (PAL) in US Adults-2019

PURPOSE

Physical activity levels (PAL) are associated with mortality risk and were instrumental in estimating national energy requirements, but we are unaware of population-based estimates of PAL in US adults. Thus, we conducted a nationwide survey using a validated previous-day recall method to estimate PAL and the behavioral determinants of low and higher PAL.

METHODS

Participants from the AmeriSpeak panel 20-75 yr of age ( N = 2640) completed Activities Completed over Time in 24-hours previous-day recalls. PAL values were estimated as the average metabolic equivalent value over 24 h. Recalls were conducted on randomly selected days in October and November 2019. Survey sample design weights were applied to reflect the US population.

RESULTS

Mean age was 45.3 yr, 51% were female, 67% were non-Hispanic White, and 37% had a body mass index of ≥30 kg·m -2 . US adults reported a mean PAL of 1.63 (95% confidence interval, 1.60-1.65), and 39% (37%-42%) of adults reported PAL ≥1.6 on a given day. Men reported higher PAL than women (1.67 vs 1.59), and older adults reported lower PAL. Adults with PAL <1.4 spent 81% (12.1 h·d -1 ) of their waking day sedentary and 19% (2.7 h·d -1 ) in total physical activity. Adults with PAL considered to be "active"(1.6-1.89) spent only 49% (8.0 h·d -1 ) of their waking day sedentary, and 51% (8.3 h·d -1 ) physically active.

CONCLUSIONS

Our study provides novel estimates of PAL in a nationwide sample of US adults and a description of the type and intensity of sedentary and physically active behaviors contributing to low and higher PAL. These findings may inform public health messages aimed at increasing physical activity in adults and potentially contribute to obesity prevention efforts.

Changes in body size and body composition in survivors of childhood cancer: seven years follow-up of a prospective cohort study

BACKGROUND & AIMS

Cancer treatment is known to have impact on nutritional status, and both underweight and overweight have been reported in several studies in survivors. A limitation of most studies is that they relied on retrospective data or were limited to a subgroup of patients. The current study aims to describe changes in body size and body composition prospectively seven years after diagnosis in a heterogeneous sample of childhood cancer survivors and to evaluate associated factors.

METHODS

The study population consisted of children diagnosed with hematological, solid and brain malignancies aged 0-18 years at diagnosis. Data of body size, body composition, and associated factors were collected at diagnosis, one year and seven years after diagnosis.

RESULTS

In the total cohort mean BMI z-score increased during treatment. In children with hematological and brain malignancies BMI z-score continued to increase after end of treatment leading to quadrupling of the prevalence of obesity seven years after diagnosis. BMI at diagnosis (β = -0.34, P = 0.007) and maternal BMI (β = 0.25, P = 0.046) were associated with the increase in BMI z-score. Mean fat mass (FM) z-score, already high at diagnosis, increased during treatment in children with hematological and brain malignancies and evened out during follow-up. Changes in FM z-score were predicted by type of malignancy (hematologic malignancy versus solid tumor β = 0.48, P = 0.008; brain tumor versus solid tumor β = 0.45, P = 0.012). Mean fat free mass (FFM) z-scores started low at diagnosis, particularly in patients with brain tumors, increased during treatment in patients with solid and brain malignancies, though decreased in children with hematological malignancies. At 7 years follow-up a clear increase to normal was seen. Age at diagnosis (β = 0.43, P = 0.004) and initial FFM (β = -0.49, P = 0.001) were found to be significant predictors for changes in FFM z-scores.

CONCLUSIONS

The finding that the once obtained extra weight and FM during treatment persisted after termination of treatment in children with hematological and brain malignancies, stresses the importance to create awareness about the risk of developing overweight in children during cancer treatment.

Physical and Psychosocial Health in Pediatric Uveitis Patients

BACKGROUND

To investigate the possible associations between childhood noninfectious uveitis and cardio-respiratory fitness, physical activity, health related quality of life and fatigue.

METHODS

Cross-sectional analysis of 23 patients with noninfectious uveitis, aged 8-18 years. BMI, exercise capacity, muscle strength and physical activity were measured. Health-related quality of life and fatigue were assessed. The results were compared to standardized values for age matched healthy children.

RESULTS

Twenty-three patients were included. Children with uveitis had a higher bodyweight and body mass index. Children with uveitis had lower cardio-respiratory fitness and they were less physically active, but they experienced a normal quality of life and normal fatigue. Parents of children with uveitis reported a lower quality of life and more fatigue for their children than parents of healthy children.

CONCLUSION

Our study indicates that children with noninfectious uveitis are at risk of developing lower physical and psychosocial health.

Volleyball practice increases bone mass in prepubescent boys during growth: A 1-yr longitudinal study

The aim of this longitudinal study was to examine the effects of 1-yr of volleyball practice on the bone mass development in the growing skeleton among prepubescent children. Twenty volleyball players and nine teen matched control boys (Tanner stage 1, at the start of the study) were followed over a 1-yr period. Bone mineral density (BMD, g/cm²), bone mineral content (BMC, g) were measured by dual-energy X-ray absorptiometry on the whole body, lumbar spine (L2–L4), legs, arms, femoral necks, hips and radii. At follow-up, in comparison with controls, volleyball players gained more BMD in whole body (4.5% vs 1.7%; p = 0.014), both nondominant and dominant arms (5.8% vs 1.1% p = 0.005, and 6% vs 2.1%; p = 0.003, respectively), both nondmoninat and dominant legs (9% vs 4.8%; p = 0.005 and 10.7% vs 6% p = 0.0025; respectively), dominant ultradistal radius (10.4% vs 0.9%; p = 0.005), dominant third distal radius (9.6% vs 3.71%; p = 0.023), dominant whole radius (7.4% vs 3.1%; p = 0.017), lumbar spine L2-L4 (9.9% vs 2.8%; p = 0.004), femoral neck (4.7% vs 1.6%; p = 0.034), trochanter (6% vs 1.5%; p<0.001) and total hip (6.1% vs 2.6%; p = 0.006). Volleyball players gained more BMC in both nondominant and dominant arms (25.1% vs 13.4%; p = 0.003, and 26.1% vs 15.6%; p<0.001 respectively), both nondominant and dominant legs (20.2% vs 14.5%; p = 0.004 and 23% vs 16%; p = 0.004, respectively), dominant ultradistal radius (22.4% vs 8.7%; p = 0.002), dominant third distal radius (20.9% vs 5.9%; p = 0.001), dominant whole radius (20% vs 13%), nondominant third distal radius (14.5% vs 5.9%; p = 0.001), nondominant whole radius (21.1% vs 12%; p = 0.002), lumbar spine L2-L4 (21.1% vs 13.7%; p = 0.007), femoral neck (25.9% vs 8.7%; p = 0.007), trochanter (23.5% vs 17.1%; p = 0.006), and total hip (16.3% vs 11.3%; p = 0.009) than controls. A close correlation was observed between the increment (Δ) of whole body lean mass and increased (Δ) BMD and BMC in whole body (r = 0.43, p<0.01, r = 0.73, p<0.001; respectively), lumbar spine (r = 0.54, r = 0.61, p<0.001; respectively), trochanter (r = 0.46, p<0.01, r = 0.35, p<0.05; respectively), and total hip (r = 0.53, p<0.01, r = 0.6, p<0.0001; respectively). In summary, 1-yr of volleyball practice has an osteogenic effect on bone mass in loaded sites in prepubescent boys.

Associations between Psycho-Hedonic Responses to Sweet and Savoury Tastes with Diet and Body Composition in a Sample of Asian Females

Taste preferences guide food choices and dietary behaviours, yet few studies have shown a relationship between sweet and savoury taste preference and differences in dietary intakes or energy consumed from different "taste clusters". We investigated differences in psycho-hedonic responses to sweet and savoury tastes and their association with energy intake, proportion of energy from macronutrients and energy intake from different "taste clusters". In addition, we evaluated correspondence between two methods to classify "sweet-liker" status and the overlap between sweet and savoury taste preferences. Psycho-hedonic responses to sweet and savoury tastes of female participants (n = 66) were captured via staircase paired preference and the "sweet-liker phenotype" classification method. Quantitative dietary energy and macronutrient intakes were measured using three-day food diary, and the relative contributions of specific taste clusters to energy intake were derived for each participant. All participants completed anthropometric assessments measuring body mass index (BMI) and adiposity. Results showed no association between sweet and savoury preferences with dietary energy or macronutrient intakes, though there was a trend towards higher sweet food consumption among "sweet-likers". A higher preference for savouriness was not associated with differences in daily energy intake, energy intake from protein, BMI or adiposity levels. There was little overlap in sweet and savoury preferences, suggesting a bi-modal split in taste preferences. "Sweet-likers" preferred a higher mean sucrose concentration than sweet "dislikers" (p < 0.001) indicating agreement between the two approaches. Future studies should consider comparing taste-liker differences using food choice tasks to address the current gap between taste preference measures and actual dietary behaviours.

Association of Lifestyle and Body Composition on Risk Factors of Cardiometabolic Diseases and Biomarkers in Female Adolescents

BACKGROUND

Female adolescents are considered a risk group for cardiometabolic disease due to their lifestyle (LS).

OBJECTIVE

To evaluate the association between LS classes and body composition groups with cardiometabolic disease risk factors and pro- and anti-inflammatory biomarkers in female adolescents.

METHODS

This cross-sectional study was carried out with female adolescents aged 14 to 19 years, from Viçosa-MG, Brazil. Latent class analysis assessed LS classes. Kinanthropometric measurements were taken together with the body fat percentage (BF%), being analyzed by the Dual Energy X-ray Absorptiometry (DEXA) equipment. Blood pressure and biochemical parameters were analyzed in the Health Division of the Federal University of Viçosa. The pro- and anti-inflammatory biomarkers were analyzed using Luminex technology. Associations with biomarkers were estimated by multiple linear regression.

RESULTS

405 female adolescents were evaluated. The majority, 82.57%, 72.90%, and 65.31%, were classified as inactive by the number of steps, with high screen and cell phone time, respectively. Furthermore, 41.55% did meet the minimum of 60 minutes of moderate-to-vigorous physical activity (MVPA) and 54.69% had high values of BF% (DEXA). The "Sedentary & Inactive LS" class together with the high levels of weight and BF% were associated with increased levels of blood pressure, lipid profile, and uric acid. It was also found that "Inactive & Sedentary LS", high BF%, insulin resistance, and ultra-sensitive C-reactive protein were associated with the concentrations of proinflammatory biomarkers of tumor necrosis factor-α, interleukin-6, and leptin.

CONCLUSION

We concluded that female adolescents with overweight/obese and high BF% presented higher values of anthropometric indicators, levels of blood pressure, concentration of uric acid and hs-CRP, and lower concentration of HDL. Inactive and Sedentary lifestyle of these girls, along with excess body fat, insulin resistance, and higher concentrations of hs-CRP were associated with the higher concentration proinflammatory markers.

Late subadult ontogeny and adult aging of the human thorax reveals divergent growth trajectories between sexes

Sexual dimorphism is an important feature of adult thorax morphology, but when and how sex-related differences in the ribcage arise during ontogeny is poorly known. Previous research proposed that sex-related size differences in the nasal region arise during puberty. Therefore, we explore whether ribcage sexual dimorphism also arises at that time and whether this sexual dimorphism is maintained until old age. We measured 526 (semi)landmarks on 80 CT-based human ribcage reconstructions, on individuals ranging from 7 to 65 year-old. The 3D coordinates were submitted to the Procrustes superimposition and analyzed. Our results show that the trajectories of thorax size and shape between sexes diverge at around 12 years of age, and continue slightly diverging until old age. The differential ontogenetic trends cause adult male ribcages to become deeper, shorter, and wider than female. Our results are consistent with the evidence from the cranial respiratory system, with the development of sexual dimorphism probably related to changes in body composition during puberty combined with changes in the reproductive system.

Postural transitions detection and characterization in healthy and patient populations using a single waist sensor

Background

Sit-to-stand and stand-to-sit transitions are frequent daily functional tasks indicative of muscle power and balance performance. Monitoring these postural transitions with inertial sensors provides an objective tool to assess mobility in both the laboratory and home environment. While the measurement depends on the sensor location, the clinical and everyday use requires high compliance and subject adherence. The objective of this study was to propose a sit-to-stand and stand-to-sit transition detection algorithm that works independently of the sensor location.

Methods

For a location-independent algorithm, the vertical acceleration of the lower back in the global frame was used to detect the postural transitions in daily activities. The detection performance of the algorithm was validated against video observations. To investigate the effect of the location on the kinematic parameters, these parameters were extracted during a five-time sit-to-stand test and were compared for different locations of the sensor on the trunk and lower back.

Results

The proposed detection method demonstrates high accuracy in different populations with a mean positive predictive value (and mean sensitivity) of 98% (95%) for healthy individuals and 89% (89%) for participants with diseases.

Conclusions

The sensor location around the waist did not affect the performance of the algorithm in detecting the sit-to-stand and stand-to-sit transitions. However, regarding the accuracy of the kinematic parameters, the sensors located on the sternum and L5 vertebrae demonstrated the highest reliability.

Body image disorders associated with lifestyle and body composition of female adolescents

OBJECTIVE

To investigate the association between body image disorders and the lifestyle and body composition of female adolescents.

DESIGN

Cross-sectional study.

SETTING

The Body Shape Questionnaire (BSQ) and Silhouette Scale and Sociocultural Attitudes Towards Appearance Questionnaire-3 were used to evaluate the participants' body image. Body composition was evaluated by a Dual-Energy X-ray Absorptiometry equipment, and lifestyles were identified by latent class analysis (LCA) using the poLCA package for R.

PARTICIPANTS

Female adolescents aged 14-19 years old, in the city of Viçosa-MG, Brazil.

RESULTS

In total, 405 girls participated in the study. Almost half of the participants were dissatisfied with their current physical appearance (51·4 %), presented body perception distortions (52·9 %). 47·3 % of the adolescents were dissatisfied with their body according to the BSQ, and another 8 % severely so. Subjects with an 'Inactive and Sedentary' latent lifestyle were 1·71 times as likely to feel dissatisfied as those with active and sedentary or inactive and non-sedentary lifestyles (95 % CI 1·08, 2·90, P = 0·047). Body image disorders showed an association with decreased amounts of moderate and vigorous physical activity, high screen time, increased alcohol consumption and excess body fat.

CONCLUSIONS

Particular patterns of lifestyle and body composition seem to be associated in female adolescents with dissatisfaction with, distortion of and excessive concern about appearance. Specifically, physical inactivity, sedentary behaviour, alcohol consumption and high body fat percentage may be strongly linked to body image disorders.

Metabolism, bioenergetics and thermal physiology: influences of the human intestinal microbiota

The micro-organisms which inhabit the human gut (i.e. the intestinal microbiota) influence numerous human biochemical pathways and physiological functions. The present review focuses on two questions, 'Are intestinal microbiota effects measurable and meaningful?' and 'What research methods and variables are influenced by intestinal microbiota effects?'. These questions are considered with respect to doubly labelled water measurements of energy expenditure, heat balance calculations and models, measurements of RMR via indirect calorimetry, and diet-induced energy expenditure. Several lines of evidence suggest that the intestinal microbiota introduces measurement variability and measurement errors which have been overlooked in research studies involving nutrition, bioenergetics, physiology and temperature regulation. Therefore, we recommend that present conceptual models and research techniques be updated via future experiments, to account for the metabolic processes and regulatory influences of the intestinal microbiota.

Evaluation of lifestyle of female adolescents through latent class analysis approach

BACKGROUND

Lack of regular physical activity, high sedentary behavior and presence of unbalanced alimentary practices are attitudes associated with an inadequate lifestyle among female adolescents.

OBJECTIVE

to assess the lifestyle of female adolescents based on measurements of behavioral variables.

METHODS

Cross-sectional study with 405 female adolescents between 14 and 19 years old, resident and attending public schools in Viçosa (state of Minas Gerais). Their lifestyle was analyzed by the Physical Activity Recall, number of steps, screen time (ST), cellphone time (CT), sitting time, food frequency questionnaire (FFQ), and alcohol and tobacco consumption. With multiple correspondence analysis it was possible to observe dispersion and approximation of the variables' categories. Latent class analysis (LCA) was used for modeling the "lifestyle" variable, having been conducted in the poLCA (Polychromous Variable Latent Class Analysis) package of the R statistical software.

RESULTS

The mean age was 15.92 ± 1.27 years. Most of the adolescents were considered physically inactive (78%) and with low number of steps (82.57%); 41.45% reported not performing Moderate to Vigorous Physical Activities (MVPA) adequately. Sedentary behavior was found high when assessing ST (72.90%) and CT (65.31%). It was found the best fitted latent class model for the lifestyle (p-G2 = 0.055, p-χ2 = 0.066) featured three latent classes and one covariate (alcohol): Class 1, 'Inactive and Sedentary' (γ = 77.5%); Class 2, 'Inactive and Non-sedentary lifestyle (γ=16.31%); and Class 3, 'Active and sedentary' (γ=6.19%). Female adolescents that had 'never consumed alcohol' were 2.26 times as likely (log OR = 0.8174; p = 0.033) to belong to class 3 (Active & Sedentary lifestyle) than to class 1 (Inactive & Sedentary lifestyle).

CONCLUSION

Latent class analysis model with five manifest variable (MVPA, number of steps, ST, sitting time and number of meals) and alcohol consumption like covariate showed itself to be an accurate and objective method in the assessment of female adolescents' lifestyle. Female adolescents that had 'never consumed alcohol' were more as likely to belong to class 'Active & Sedentary lifestyle' than to class Inactive & Sedentary lifestyle. An inactive and sedentary lifestyle is coupled to other unhealthy behaviors during adolescence, possibly carrying over into adult life.

Feasibility, reliability, and validity of using accelerometers to measure physical activities of patients with stroke during inpatient rehabilitation

Promoting physical activities is important for medical and functional recovery after stroke. Therefore, an accurate and convenient measurement of physical activities is necessary to provide feedback on functional status and effects of rehabilitative interventions. We assessed the feasibility, reliability, and validity of wearing accelerometers to monitor physical activities of stroke patients by estimating energy expenditure. This was a prospective observational quantitative study conducted in an inpatient rehabilitation unit. Twenty-four patients with subacute stroke were enrolled. They wore accelerometers on wrists and ankles for three consecutive weekdays. The feasibility was evaluated by daily wear-time. The test-retest reliability was determined by intra-class correlation coefficient. The validity was evaluated by comparing accelerometeric data to behavior mappings using Mann-Whitney U test, Spearman’s rho correlation coefficient (r) and Bland-Altman plots. Average wearing time for four accelerometers was 20.99 ± 3.28 hours per day. The 3-day accelerometer recording showed excellent test-retest reliability. For sedentary activities, wrist accelerometers showed higher correlation with direct observation than ankle accelerometers. For light to moderate activities, ankle accelerometers showed higher correlation with direct observation than wrist accelerometers. Overall, combined models of accelerometers showed higher correlation with direct observation than separate ones. Wearing accelerometers for 24 h may be useful for measuring physical activities in subjects with subacute stroke in an inpatient rehabilitation unit.

Judo Practice in Early Age Promotes High Level of Bone Mass Acquisition of Growing Boys' Skeleton

The current study aimed to exhibit effects of judo training for at least 2 yr on bone mass parameters in growing boys. Our population was composed of one hundred and thirty boys in tanner stage 1 and aged 10.52 ± 0.86 yr. Eleven judo players were therefore, excluded from the study because they do not have participate regularly to the judo training sessions during the last 2 yr. The resting sample was divided into two groups: 50 judo players (JU group) and 69 controls (C group). Bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) were evaluated by using dual-photon X-ray absorptiometry on weight-bearing sites: the whole body, lumbar spine (L2-L4), legs, femoral necks and hips and on the non-weight bearing sites: arms and radiuses. Our findings displayed that judo participation was markedly associated with greater values of bone mass parameters in young judo players than control group. Accordingly, the BMD and BA results exhibited significant differences in the whole body, legs, dominant total hip, arms and both whole radiuses in addition to the dominant femoral neck, the non-dominant total hip and except the non-dominant whole radius for the BMC parameter. Additionally, data of the subject within t test has shown significant differences of bone mass parameters only in the non weight-bearing sites in the judo players without any obvious variation in the controls. Differences of BMD observed on the dominant arm and whole radius in addition to the increased BMC values showed in the dominant whole radius compared with their contra-lateral sites in judo players without any marked variation of BA parameters in all sites in both groups. In growing boys, judo practice was obviously associated with osteogenic effects in specific sites.

BODY DISSATISFACTION, PHYSICAL ACTIVITY, AND SEDENTARY BEHAVIOR IN FEMALE ADOLESCENTS

Objective:

To evaluate the association of body image with physical activity level, body composition, and sedentary behavior (SB) of female adolescents.

Methods:

Exploratory cross-sectional study conducted with 120 female adolescents aged between 14-19 years, from the city of Viçosa, Minas Gerais, Southeast Brazil. Body image was evaluated with a Body Silhouette Scale (BSS) and a Body Shape Questionnaire (BSQ). Weight, height, and waist circumference values were analyzed, as well as the waist-to-height ratio and body fat percentage. The physical activity level (PAL) was assessed by 24-hour Physical Activity Recall and SB by screen time, that is, time spent in front of a TV, playing video game, on the computer and using tablets, and, separately, the cell phone time.

Results:

Mean age was 16.5±1.5 years, and most adolescents were eutrophic (77.6%), sedentary/low PAL (84.2%), with high screen time (85.2%) and cell phone time (58.7%). Body dissatisfaction was stated in 40.6% of BSQ and 45.8% of BSS evaluations. Body distortion was identified in 52.9% of participants. All body composition measures, along with cell phone time and PAL, were associated with body dissatisfaction, the more active adolescents presenting higher levels of dissatisfaction.

Conclusions:

This study concluded that female adolescents with higher cell phone time also present higher body dissatisfaction, as well as the most physically active ones. All body composition measurements were associated with body dissatisfaction, mainly body mass index, waist circumference, and waist-to-height ratio.

Subjective and objective assessment of physical activity - Influence of newly diagnosed exercise induced bronchoconstriction and gender

AIM

To investigate if occurrence of newly diagnosed exercise induced bronchoconstriction (EIB) would affect adolescents' ability to assess their physical activity.

METHODS

99 selected adolescents with and 47 adolescents without self-reported exercise induced dyspnea were included. All of the 146 adolescents then performed a standardized exercise challenge test on a treadmill with dry-air inhalation to detect EIB. Free living physical activity was assessed during seven days with both accelerometer (objective assessment) and a validated activity diary (subjective assessment). Height, weight and subjective sleep were recorded.

RESULTS

Out of the 146 adolescents 49 were diagnosed with EIB. Forty-six of the adolescents with EIB (35 girls and 11 boys) and 84 of the control adolescents (45 girls and 39 boys) had complete 7 day activity diary and accelerometer data. There were no differences in age, BMI and sleep between EIB and control adolescents. Boys with EIB overestimated subjective assessment compared to objective assessment more than girls with EIB. No difference was seen between control boys and girls. Furthermore, boys with EIB reported a much higher frequency of high intensity exercise than girls with EIB, but no difference was observed between control boys and girls.

CONCLUSION

Adolescent boys with newly diagnosed EIB overestimated their physical activity compared to EIB girls. Caution may thus be used when choosing methods measuring level of physical activity in this group and especially when investigating gender differences.

Stationary cycling exergame use among inactive children in the family home: a randomized trial

Exergames may be one way to increase child physical activity, but long term adherence has seen little research attention. The primary objective of this study was to evaluate the usage of an exergame bike in comparison to a stationary bike in front of a TV across 3-months within a family home environment among children aged 10-14 years old. Seventy-three inactive children were recruited through advertisements and randomized to either the exergame condition (n = 39) or the standard bike condition (n = 34). Weekly bike use was recorded in a log-book. Both groups declined in bike use over time (t = 3.921, p < .01). Although the exergame group reported higher use (t = 2.0045, p < .05), this was most prominent during the first week. Overall, these results do not support exergames as a standalone physical activity intervention, and suggest that short duration examinations of exergames may be misleading.

Measuring Physical Activity in Juvenile Idiopathic Arthritis: Activity Diary Versus Accelerometer

Objective.

(1) To determine convergent validity of an activity diary (AD) and accelerometer (Actical brand/Phillips-Respironics) in measuring physical activity (PA) in children with juvenile idiopathic arthritis (JIA). (2) To determine how many days give reliable results. (3) To analyze effects of correcting accelerometer data for non-wear.

Methods.

Patients with JIA (8–13 yrs) were recruited from 3 Dutch pediatric rheumatology centers. PA was assessed for 7 days with an AD and accelerometer, and was expressed as mean min/day of rest, light PA (LPA), moderate to vigorous PA (MVPA), and PA level (PAL). To analyze convergent validity, intraclass correlation coefficients (ICC) were calculated and paired sample Student t tests were performed. The required number of days to achieve reliable results was calculated using the Spearman-Brown prophecy formula.

Results.

Convergent validity between AD and accelerometer was moderate for rest and PAL (ICC 0.41). ICC for LPA and MVPA were < 0.24. AD overestimated PAL and MVPA compared with the accelerometer. Wearing the accelerometer 7–19 days gave reliable PA estimates on group and individual levels. For the AD, 13–36 days were needed. Adjusting accelerometer data for non-wear resulted in a clinically relevant higher mean number of min/day spent in LPA (effect size 1.12), but not in MVPA (effect size 0.44).

Conclusion.

Convergent validity between AD and accelerometer is moderate to poor. In children with JIA, 1-week assessment with an accelerometer is sufficient to measure PA (all levels) reliably. On an individual level and for clinical use, 3 weeks are required. Additional use of AD enables correction for non-wear of accelerometer data.

Analysis of energy metabolism in humans: A review of methodologies

Background

Obesity is a consequence of chronic energy imbalance. We need accurate and precise measurements of energy intake and expenditure, as well as the related behaviors, to fully understand how energy homeostasis is regulated in order to develop interventions and evaluate their effectiveness to combat the global obesity epidemic.

Scope of review

We provide an in-depth review of the methodologies currently used to measure energy intake and expenditure in humans, including their principles, advantages, and limitations in the clinical research setting. The aim is to provide researchers with a comprehensive guide to conduct obesity research of the highest possible quality.

Major conclusions

An array of methodologies is available to measure various aspects of energy metabolism and none is perfect under all circumstances. The choice of methods should be specific to particular research questions with practicality and quality of data the priorities for consideration. A combination of complementary measurements may be preferable. There is an imperative need to develop new methodologies to improve the accuracy and precision of energy intake assessments.

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Image-based technology is a significant step to improve energy intake measurement.

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Physical activity informs patterns but not absolute energy expenditure.

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Combining complementary measurements overcomes shortfalls of individual methods.

Does a family history of coronary heart disease modify the relationship between physical activity and blood pressure in young adults?

BACKGROUND

The purpose of this study was to examine the relationships between physical activity, a family history (FH) of coronary heart disease (CHD), and blood pressure (BP) in young adults. We were specifically interested in determining whether the relationship between moderate-to-vigorous physical activity and BP was modified by a FH of CHD.

METHODS

Subjects were 230 (103 males, 127 females) university students. Family history was self-reported and habitual physical activity was assessed with a 3-day activity diary. Indicators of habitual physical activity included estimated daily energy expenditure (EE) and EE in moderate-to-vigorous physical activity (MVPA) [median metabolic equivalent (MET) > or =4.8] and inactivity (IA) (MET<2.8). Blood pressure was measured by an automated device according to standard procedures.

RESULTS

A large proportion of the sample (63% of males and 68% of females) reported a FH of CHD. In general, correlations between physical activity and BP were low (r<0.30), but in the expected direction (i.e., positive for IA and negative for MVPA and EE). In males IA was significantly related to BP (r =0.25-0.29), but MVPA was not significantly related to BP (r= -0.01 to -0.16). In females diastolic BP was significantly related to IA (r= -0.21) and total EE (r= -0.18). Total EE was significantly correlated to DBP (r= -0.22) in males and to mean arterial pressure (r= -0.18) in females. No significant differences in BP were found between subjects with or without a FH of CHD. Slightly stronger correlations emerged between MVPA and BP for subjects with a negative FH of CHD compared to those with a positive FH of CHD.

CONCLUSION

These data show a significant association between sedentary behavior and blood pressure in young adults. It is suggestive that the magnitude of the relationship between MVPA and BP may be modified by a FH of CHD. Thus, individuals with a FH of CHD may not be as responsive to increased levels of MVPA compared to those without a FH of CHD.

Physical activity in children with Juvenile Idiopathic Arthritis compared to controls

BACKGROUND

To compare physical activity (PA) in children with juvenile idiopathic arthritis (JIA) with controls and to analyse the effect of disease specific factors on PA in children with JIA treated according to current treatment regimes.

METHODS

PA was measured with a 7-day activity diary and expressed as physical activity level (PAL). Moderate to vigorous physical activity (MVPA) (hours/day) and sedentary time (hours/day) was determined. In children with JIA, medication, the number of swollen and/or painful joints, disease activity, functional ability, pain and well-being was determined. Multivariate regression analysis was performed to analyze differences in PA between JIA and controls, adjusted for influences of age, gender, season, Body Mass Index (BMI) and to analyze predictors of PA in JIA patients.

RESULTS

Seventy-six children with JIA (26 boys and 50 girls, mean ± SD age 10.0 ± 1.4 years) and 131 controls (49 boys and 82 girls, mean ± SD age 10.4 ± 1.2 years) participated in this study. Children with JIA had a significantly lower PAL (0.10, p = 0.01) corrected for age, BMI, gender and season. They spent less time in MVPA (0.41 h/day, p = 0.06) and had a significantly higher mean time spent in sedentary activities (0.59 h/day, p 0.02) compared to controls. The activity level of children with JIA was related to age, gender, season, feeling of well-being and pain.

CONCLUSION

Children with JIA have a lower PAL, spent less time in MVPA and spent more time on sedentary activities compared to controls despite current medical treatment and PA encouragement.

TRIAL REGISTRATION

Data of the children with JIA are from the Rheumates@work study ISRCTN92733069 .

Handball Practice Enhances Bone Mass in Specific Sites Among Prepubescent Boys

This investigation's purpose is to focus on the effects of practicing handball for at least 2 yr on bone acquisition among prepubescent boys. One hundred prepubescent boys aged 10.68 ± 0.85 yr were divided into 2 groups: 50 handball players (HP group) and 50 controls (C group). Bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) were evaluated by using dual-photon X-ray absorptiometry on the whole body, lumbar spine (L2-L4), legs, arms, femoral necks, hips and radiuses. Results showed greater values of BMD in both right and left femoral neck and total hip in handball players than in controls. In addition, handball players had higher values of legs and right total hip BMC than controls without any obvious variation of BA measurement in all sites between groups. All results of the paired t-test displayed an obviously marked variation of bone mass parameters between the left and right sides in the trained group without any marked variation among controls. Data showed an increased BMD of the supporting sites between the left and the right leg among handball players. However, "BMC" results exhibited higher values in the right than in the left total hip, and in the right total radius than in the left correspondent site. In addition, differences in the "BA" measurements were observed in the left total hip and in the right arm. Specific bone sites are markedly stimulated by handball training in prepubescent boys.

Children with cerebral palsy do not achieve healthy physical activity levels

AIM

This study compared daily activity energy expenditure (AEE) in children with cerebral palsy with a control group and investigated whether the children achieved healthy levels of physical activity.

METHODS

We enrolled eight children with bilateral cerebral palsy, from eight to 10 years of age, and a group of controls matched for age and gender. For three days, physical activity was simultaneously measured by accelerometers and self-reports using a diary. The daily AEE results were compared between groups and methods. The number of children that achieved healthy physical activity levels in each group was explored.

RESULTS

Children with cerebral palsy had significantly lower daily AEE, as measured by accelerometers, than the controls, and they did not achieve the healthy moderate to heavy physical activity level defined in the Nordic Nutrition Recommendations. Self-reports using the diaries resulted in an overestimation of physical activity compared with the ankle accelerometer measurements in both groups.

CONCLUSION

Our investigation of physical activity in children with cerebral palsy and controls using accelerometers and a diary found low levels of daily AEE and physical activity, and these results were most prominent in the group with cerebral palsy. The diaries overestimated physical activity in both groups.

Benefits of strict rest after acute concussion: a randomized controlled trial

OBJECTIVES

To determine if recommending strict rest improved concussion recovery and outcome after discharge from the pediatric emergency department (ED).

METHODS

Patients aged 11 to 22 years presenting to a pediatric ED within 24 hours of concussion were recruited. Participants underwent neurocognitive, balance, and symptom assessment in the ED and were randomized to strict rest for 5 days versus usual care (1-2 days rest, followed by stepwise return to activity). Patients completed a diary used to record physical and mental activity level, calculate energy exertion, and record daily postconcussive symptoms. Neurocognitive and balance assessments were performed at 3 and 10 days postinjury. Sample size calculations were powered to detect clinically meaningful differences in postconcussive symptom, neurocognitive, and balance scores between treatment groups. Linear mixed modeling was used to detect contributions of group assignment to individual recovery trajectory.

RESULTS

Ninety-nine patients were enrolled; 88 completed all study procedures (45 intervention, 43 control). Postdischarge, both groups reported a 20% decrease in energy exertion and physical activity levels. As expected, the intervention group reported less school and after-school attendance for days 2 to 5 postconcussion (3.8 vs 6.7 hours total, P < .05). There was no clinically significant difference in neurocognitive or balance outcomes. However, the intervention group reported more daily postconcussive symptoms (total symptom score over 10 days, 187.9 vs 131.9, P < .03) and slower symptom resolution.

CONCLUSIONS

Recommending strict rest for adolescents immediately after concussion offered no added benefit over the usual care. Adolescents' symptom reporting was influenced by recommending strict rest.

Accuracy of self-reported physical activity levels in obese adolescents

Introduction. Self-reported measures of habitual physical activity rely completely on the respondent's ability to provide accurate information on their own physical activity behaviours. Our aim was to investigate if obese adolescents could accurately report their physical activity levels (PAL) using self-reported diaries. Methods. Total energy expenditure (TEE) was measured using doubly labelled water (DLW) and resting energy expenditure (REE) was measured via indirect calorimetry. Activity energy expenditure (AEE) and PAL values were derived from measured TEE and REE. Self-reported, four-day activity diaries were used to calculate daily MET values and averaged to give an estimated PAL value (ePAL). Results. Twenty-two obese adolescents, mean age 13.2 ± 1.8 years, mean BMI 31.3 ± 4.6 kg/m², completed the study. No significant differences between mean measured and estimated PAL values were observed (1.37 ± 0.13 versus 1.40 ± 0.34, P = 0.74). Bland Altman analysis illustrated a significant relationship (r = −0.76, P < 0.05) between the two methods; thus the bias was not consistent across a range of physical activity levels, with the more inactive overreporting their physical activity. Conclusion. At an individual level, obese adolescents are unlikely to be able to provide an accurate estimation of their own activity.

Is a coded physical activity diary valid for assessing physical activity level and energy expenditure in stroke patients?

Objectives

to determine the concurrent validity of a physical activity diary for measuring physical activity level and total energy expenditure in hospitalized stroke patients.

Method

Sixteen stroke patients kept coded activity diaries and wore SenseWear Pro2 multi-sensor activity monitors during daytime hours for one day. A researcher observed the patients and completed a diary. Data from the patients' diaries were compared with observed and measured data to determine total activity (METs*minutes), activity level and total energy expenditure.

Results

Spearman correlations between the patients' and researchers' diaries revealed a high correlation for total METs*minutes (r_s = 0.75, p<0.01) for sedentary (r_s = 0.74,p<0.01) and moderate activities (r_s = 0.71,p<0.01) and a very high correlation (r_s = 0.92, p<0.01) for the total energy expenditure. Comparisons between the patients' diaries and activity monitor data revealed a low correlation (r_s 0.29) for total METs*minutes and energy expenditure.

Conclusion

Coded self-monitoring activity diaries appear feasible as a low-tech alternative to labor-intensive observational diaries for determining sedentary, moderate, and total physical activity and for quantifying energy expenditure in hospitalized stroke patients. Given the poor correlation with objective measurements of physical activity, however, further research is needed to validate its use against a gold-standard measure of physical activity intensity and energy expenditure.

Prediction models discriminating between nonlocomotive and locomotive activities in children using a triaxial accelerometer with a gravity-removal physical activity classification algorithm

The aims of our study were to examine whether a gravity-removal physical activity classification algorithm (GRPACA) is applicable for discrimination between nonlocomotive and locomotive activities for various physical activities (PAs) of children and to prove that this approach improves the estimation accuracy of a prediction model for children using an accelerometer. Japanese children (42 boys and 26 girls) attending primary school were invited to participate in this study. We used a triaxial accelerometer with a sampling interval of 32 Hz and within a measurement range of ±6 G. Participants were asked to perform 6 nonlocomotive and 5 locomotive activities. We measured raw synthetic acceleration with the triaxial accelerometer and monitored oxygen consumption and carbon dioxide production during each activity with the Douglas bag method. In addition, the resting metabolic rate (RMR) was measured with the subject sitting on a chair to calculate metabolic equivalents (METs). When the ratio of unfiltered synthetic acceleration (USA) and filtered synthetic acceleration (FSA) was 1.12, the rate of correct discrimination between nonlocomotive and locomotive activities was excellent, at 99.1% on average. As a result, a strong linear relationship was found for both nonlocomotive (METs = 0.013×synthetic acceleration +1.220, R² = 0.772) and locomotive (METs = 0.005×synthetic acceleration +0.944, R² = 0.880) activities, except for climbing down and up. The mean differences between the values predicted by our model and measured METs were −0.50 to 0.23 for moderate to vigorous intensity (>3.5 METs) PAs like running, ball throwing and washing the floor, which were regarded as unpredictable PAs. In addition, the difference was within 0.25 METs for sedentary to mild moderate PAs (<3.5 METs). Our specific calibration model that discriminates between nonlocomotive and locomotive activities for children can be useful to evaluate the sedentary to vigorous PAs intensity of both nonlocomotive and locomotive activities.

Levels and patterns of objectively-measured physical activity volume and intensity distribution in UK adolescents: the ROOTS study

BACKGROUND

Few studies have quantified levels of habitual physical activity across the entire intensity range. We aimed to describe variability in total and intensity-specific physical activity levels in UK adolescents across gender, socio-demographic, temporal and body composition strata.

METHODS

Physical activity energy expenditure and minutes per day (min/d) spent sedentary and in light, moderate, and vigorous intensity physical activity were assessed in 825 adolescents from the ROOTS study (43.5% boys; mean age 15.0 ± 0.30 years), by 4 days of individually calibrated combined heart rate and movement sensing. Measurement days were classified as weekday or weekend and according to the three school terms: summer (April-July), autumn (September-December), and spring (January-March). Gender and age were self-reported and area-level SES determined by postcode data. Body composition was measured by anthropometry and bio-electrical impedance. Variability in physical activity and sedentary time was analysed by linear multilevel modelling, and logistic multilevel regression was used to determine factors associated with physical inactivity (<60 min moderate-to-vigorous intensity physical activity/d).

RESULTS

During awake hours (15.8 ± 0.9 hrs/d), adolescents primarily engaged in light intensity physical activity (517 min/d) and sedentary time (364 min/d). Boys were consistently more physically active and less sedentary than girls, but gender differences were smaller at weekends, as activity levels in boys dropped more markedly when transitioning from weekday to weekend. Boys were more sedentary on both weekend days compared to during the week, whereas girls were more sedentary on Sunday but less sedentary on Saturday. In both genders light intensity physical activity was lower in spring, while moderate physical activity was lower in autumn and spring terms, compared to the summer term; sedentary time was also higher in spring than summer term. Adolescents with higher fatness engaged in less vigorous intensity physical activity. Factors associated with increased odds of physical inactivity were female gender, both weekend days in boys, and specifically Sunday in girls.

CONCLUSIONS

Physical activity components vary by gender, temporal factors and body composition in UK adolescents. The available data indicate that in adolescence, girls should be the primary targets of interventions designed to increase physical activity levels.

Evaluation of Actiheart and a 7 d activity diary for estimating free-living total and activity energy expenditure using criterion methods in 1·5- and 3-year-old children

Accurate and easy-to-use methods to assess free-living energy expenditure in response to physical activity in young children are scarce. In the present study, we evaluated the capacity of (1) 4 d recordings obtained using the Actiheart (mean heart rate (mHR) and mean activity counts (mAC)) to provide assessments of total energy expenditure (TEE) and activity energy expenditure (AEE) and (2) a 7 d activity diary to provide assessments of physical activity levels (PAL) using three sets of metabolic equivalent (MET) values (PALTorun, PALAdolphand PALAinsworth) in forty-four and thirty-one healthy Swedish children aged 1·5 and 3 years, respectively. Reference TEE, PALrefand AEE were measured using criterion methods, i.e. the doubly labelled water method and indirect calorimetry. At 1·5 years of age, mHR explained 8 % (P= 0·006) of the variation in TEE above that explained by fat mass and fat-free mass. At 3 years of age, mHR and mAC explained 8 (P= 0·004) and 6 (P= 0·03) % of the variation in TEE and AEE, respectively, above that explained by fat mass and fat-free mass. At 1·5 and 3 years of age, average PALAinsworthvalues were 1·44 and 1·59, respectively, and not significantly different from PALrefvalues (1·39 and 1·61, respectively). By contrast, average PALTorun(1·5 and 3 years) and PALAdolph(3 years) values were lower (P< 0·05) than the corresponding PALrefvalues. In conclusion, at both ages, Actiheart recordings explained a small but significant fraction of free-living energy expenditure above that explained by body composition variables, and our activity diary produced mean PAL values in agreement with reference values when using MET values published by Ainsworth.

Measuring physical activity in children and adolescents for dietary surveys: practicalities, problems and pitfalls

Physical inactivity is an important risk factor for many chronic diseases and contributes to obesity and poor mental well-being. The present paper describes the main advantages and disadvantages, practical problems, suggested uses, and future developments regarding self-reported and objective data collection in the context of dietary surveys. In dietary surveys, physical activity is measured primarily to estimate energy expenditure. Energy expenditure surveillance is important for tracking changes over time, particularly given the debates over the role of the relative importance of energy intake and expenditure changes in the aetiology of obesity. It is also important to assess the extent of underreporting of dietary intake in these surveys. Physical activity data collected should include details on the frequency, duration and relative intensity of activity for each activity type that contributes considerably to overall activity and energy expenditure. Problems of validity and reliability, associated with inaccurate assessment, recall bias, and social desirability bias, are well-known; children under 10 years cannot report their activities accurately. However, despite such limitations, questionnaires are still the dominant method of physical activity assessment in dietary surveys due to their low cost and relatively low participant burden. Objective, time-stamped measures that monitor heart rate and/or movement can provide more comprehensive, quantitative assessment of physical activity but at greater cost and participant burden. Although overcoming many limitations of questionnaires, objective measures also have drawbacks, including technical, practical and interpretational issues.

Enhanced bone mass and physical fitness in prepubescent basketball players

The aim of this study was to examine the effect of basketball practice on bone acquisition in the prepubertal age. In total, 48 prepubescent male basketball players aged 11.1 ± 0.8 yr, Tanner stage 1, were compared with 50 controls matched for age and pubertal stage. Areal bone mineral density, bone mineral content (BMC), and bone area (BA) in deferent sites associated with anthropometric parameters were measured by dual-energy X-ray absorptiometry. Running and jumping tests were performed. Analysis of Student's impaired t-test revealed that basketball players attained better results in all physical fitness tests (p < 0.05). They also exhibited significantly greater BMC and BA in whole body, upper and lower extremities, trochanter, total hip, and whole right and left radius (p < 0.001) compared with the controls. No significant differences were observed between groups in right and left ultradistal and third distal radius and spinal regions, BMC, and BA, whereas a significant positive correlation was reported between lean mass, BMC, and BA of lower limbs. In summary, basketball practice in prepubertal age is associated with improved physical fitness and enhanced lean and bone mass in loaded sites.

Free-living physical activity and energy expenditure of rural children and adolescents in the Nandi region of Kenya

PURPOSE

To examine the relationship between physical activity and energy demands in children and adolescents with highly active lifestyles.

METHODS

Physical activity patterns of 30 rural Kenyan children and adolescents (14 ± 1 years, mean ± SD) with median body mass index (BMI) z-score = -1.06 [-3.29-0.67] median [range] were assessed by accelerometry over 1 week. Daily energy expenditure (DEE), activity-induced energy expenditure (AEE) and physical activity level (PAL) were simultaneously determined using doubly-labelled water (DLW). Active commuting to school was assessed by global positioning system.

RESULTS

Mean DEE, AEE and PAL were 12.2 ± 3.4, 5.7 ± 3.0 MJ/day and 2.3 ± 0.6, respectively. A model combining body mass, average accelerometer counts per minute and time in light activities predicted 45% of the variance in DEE (p < 0.05) with a standard error of DEE estimate of 2.7 MJ/day. Furthermore, AEE accounted for ∼47% of DEE. Distance to school was not related to variation in DEE, AEE or PAL and there was no association between active commuting and adiposity.

CONCLUSION

High physical activity levels were associated with much higher levels of energy expenditure than observed in Western societies. These results oppose the concept of physical activity being stable and constrained in humans.

Specific sites of bone expansion depend on the level of volleyball practice in prepubescent boys

The purpose of this study was to investigate the effect of 18 months of high and low levels of volleyball practice on bone acquisition. 130 prepubescent boys (mean age 11.4 ± 0.7) were divided into a high-level training group (HLG), low-level training group (LLG), and controls. Bone mineral content (BMC) and bone area at the whole body, lumbar spine L2-L4, femoral neck of the dominant leg, and right and left radius were measured using dual-photon X-ray absorptiometry. Enhanced BMC resulted from high-training volleyball activity in all measured sites except the third left and right distal radius, which is not modified by low-level training in prepubescent players but it was accompanied by a bone area expansion in radius and weight-bearing sites for the HLG, and in legs, whole right and left radius for the LLG. Significant improvement of skeletal tissues is associated with the intensity and duration of volleyball training.

Level of agreement between methods for measuring moderate to vigorous physical activity and sedentary time in people with obstructive sleep apnea and obesity

BACKGROUND

There is ambiguity about what measures to use to best identify physical activity and sedentary behavior, and agreement between methods for measuring physical activity and sedentary behavior in people with obstructive sleep apnea syndrome (OSAS) and obesity has not been evaluated.

OBJECTIVE

The objective of this study was to examine the level of agreement between an accelerometer and a self-report questionnaire (International Physical Activity Questionnaire [IPAQ]) or a logbook for measuring time spent on moderate to vigorous physical activity and time spent sedentary in people with OSAS and obesity.

DESIGN

This prospective study was a psychometric evaluation of agreement between measurement methods.

METHODS

Thirty-nine people who were obese (body mass index: X=36.1 kg/m², SD=4.35) and had moderate to severe OSAS (apnea-hypopnea index of ≥15) were consecutively recruited from a sleep clinic in Sweden. All were treated with continuous positive airway pressure and were waiting for a follow-up sleep evaluation.

RESULTS

Agreement between the measurement methods was limited. For physical activity, the mean difference between the accelerometer and the IPAQ was 47 minutes, and the mean difference between the accelerometer and the logbook was 32 minutes. Agreement was limited for sedentary time as well; the mean difference between the accelerometer and the IPAQ was 114 minutes, and the mean difference between the accelerometer and the logbook was 86 minutes.

LIMITATIONS

The small sample size may affect the interpretation and generalizability of the results.

CONCLUSIONS

The results imply that the methods cannot be used interchangeably. A combination of an accelerometer and a daily logbook seems to provide a detailed description of physical activity and sedentary behavior.

Doubly labeled water validation of a computerized use-of-time recall in active young people

OBJECTIVE

Low levels of daily energy expenditure (insufficient physical activity and increased sedentary time) have been associated with adverse health outcomes in young people. The Multimedia Activity Recall for Children and Adolescents (MARCA) is a computerized, self-report, use-of-time tool that can assess daily energy expenditure. The study aim was to validate the MARCA for the estimation of energy expenditure in young people, using the criterion standard doubly labeled water.

MATERIALS/METHODS

Over a 15 day assessment period, 32 participants (10-18 years) completed the MARCA and underwent a doubly labeled water protocol. Indirect calorimetry was used to assess resting metabolic rate. Total daily energy expenditure (TEE) and activity-related energy expenditure (AEE) were estimated from both the MARCA and doubly labeled water. Association and agreement between methods for TEE and AEE were assessed using Spearman correlations and Bland-Altman plots, respectively.

RESULTS

Compared to doubly labeled water, the MARCA over-estimated TEE by an average of 50 kcal/day (limits of agreement -1 589 to 1 490 kcal/day) and under-estimated AEE 105 kcal/day (limits of agreement -1 404 to 1 614 kcal/day). The MARCA showed strong correlation with doubly labeled water for TEE (rho=0.70, p<0.0001) and moderate correlation for AEE (rho=0.56, p=0.0009).

CONCLUSIONS

Overall, the MARCA indicated moderate validity for the assessment of daily TEE and AEE. The wide limits of agreement indicate the MARCA has greater utility for group-level rather than individual-level estimates.

[Validity and reproducibility of a physical activity questionnaire for adolescents: adapting the Self-Administered Physical Activity Checklist]

OBJECTIVES

To evaluate test-retest reproducibility and the validity of a physical activity questionnaire for adolescents (adapted from Self-Administered Physical Activity Checklist).

METHODS

The test-retest reproducibility analysis was completed by 239 adolescents (average age 16 years, SD = 1.2; 56.4% female), and the validity analysis by 70 adolescents (average age 15.7 years, SD = 1.2; 55.7% female). All adolescents were high school students in João Pessoa, PB, in Northeastern Brazil, in 2009. The test-retest reproducibility was determined by repeated evaluations with one week interval between them. Validity of the physical activity questionnaire was assessed by comparing the results of the questionnaire with those of four 24-hour recalls (reference method).

RESULTS

The test-retest reproducibility was high (intraclass correlation coefficient: ICC = 0.88; 95%CI: 0.84 - 0.91), and the agreement was moderate for physical activity classified in two groups (< 300 min/week vs. > 300 min/week; kappa coefficient: k = 0.52). Spearman correlation coefficient comparing the questionnaire data with those of four 24-hour recalls (reference method) was moderate (rho = 0.62; p < 0001). The agreement between these measures (questionnaire and 24-hours recalls) for physical activity classified in two groups was moderate (k = 0.59).

CONCLUSIONS

The physical activity questionnaire showed high reproducibility, and moderate validity, and therefore, its use is recommended for assessing adolescents' physical activity level.

Self-report use-of-time tools for the assessment of physical activity and sedentary behaviour in young people: systematic review

Regular physical activity and limiting extended periods of sitting are two behaviours critical for the prevention of obesity in young people. The purpose of the systematic review was to synthesize the psychometric evidence for self-report use-of-time tools that assess these behaviours. Articles were retrieved that reported reliability and/or validity for use-of-time tools in participants aged 18 years or under. Outcome variables were physical activity, sedentary behaviour and energy expenditure. Study quality was appraised, and the results summarized narratively. Sixteen studies and six different tools were identified. The tools were the Previous Day Physical Activity Recall, the Three-Day Physical Activity Recall, the Physical Activity Interview, the Computerized Activity Recall, the Activitygram, and the Multimedia Activity Recall for Children and Adolescents. Overall, tools indicated moderate validity compared with objective and criterion comparison methods. Generally, validity correlation coefficients were in the range of 0.30-0.40. Correlation coefficients for test-retest reliability ranged widely from 0.24 to 0.98.

CONCLUSION

Use-of-time tools have indicated moderate reliability and validity for the assessment of physical activity and energy expenditure. Future research should focus on using criterion methods and on validating specifically for sedentary behaviour outcomes. Implementation of these tools for population surveillance should be considered.

Predictors of change in sports participation in Latino and non-Latino children

BACKGROUND

Few prospective studies have examined predictors of change in specific physical activity (PA) behaviours in different ethnic groups.

PURPOSE

To assess predictors of change in sports participation in Latino and non-Latino 5-8 year-old children in San Diego, California.

METHODS

Average sports participation frequency (days/week) was assessed by validated parent-report at baseline (Nov 2006-May 2008) and 1 year later in 541 children (45.0% male, 41.1% Latino; mean ± SD age: 6.6 ± 0.7 years) taking part in an obesity prevention study (Project MOVE). Biological (sex, age, Body Mass Index z-score), socio-cultural (ethnicity, income, care giver education), parental (PA rules, PA encouragement) and environmental factors (home PA equipment, PA location) were assessed at baseline. Associations between change in sports participation and potential predictors were studied using multilevel linear regression stratified by Latino ethnicity, adjusted for sex, baseline sport participation, study condition and recruitment area.

RESULTS

Sports participation increased over 1 year (mean change: +0.5 days; p<0.001) and change was similar for boys and girls (p=0.95), but Latino children showed a greater increase (p=0.03). The number of locations used for PA (p=0.024) and the total frequency of PA location use (p=0.018) were positively associated with increased sports participation among Latinos. No predictors were identified for non-Latino children.

CONCLUSIONS

Only factors relating to PA location were identified as predictors of change in sports participation for Latino children. Interventions targeting specific PA behaviours such as sports participation may need to consider PA locations for Latino children and be tailored for specific ethnic groups.

Feasibility of pedometers for adults with schizophrenia: pilot study

The purpose of this prospective and observational design study was to assess the feasibility of using a pedometer and step log to explore level of physical activity (PA) and to assess motivation to be physically active in adults with schizophrenia. Descriptive statistics were used to analyse data of 7 male and 5 female subjects. Pedometer data indicated that subjects walked an average of 4731.03 (±3318.19) steps and 5002.58 (±3041.03) during the first week and second week of the study, respectively. A minimum 30-min walk was recorded on an average of 3.67 (±1.82) days (week one) and 4.5 (±1.88) days (week two). Step logs, inconsistently maintained by subjects, were not able to be analysed. Examination of the Motives for Physical Activity Measure-Revised (MPAM-R) at baseline indicates that exercise fitness and body appearance were subjects' primary motives for PA participation. Study findings indicate that it is feasible to use a pedometer to monitor the level of PA. However, maintenance of a concurrent step log requires further consideration to determine realistic outcomes. Extrinsically focused motivations for PA in this study sample may predict low PA adherence.

Physical activity is inversely associated with high blood pressure independently of overweight in Brazilian adolescents

The purpose of this study was to assess the relationship between blood pressure (BP) levels and physical activity (PA) domains accounting for overweight/obesity. Adolescents aged 10 to 17 years old were recruited (n = 1021). International Obesity Task Force (IOTF) criteria were used to define overweight and obesity. High BP was defined using the Center of Disease Control and Prevention criteria. Different domains of PA (school activities, sport out of school, and leisure time PA) were assessed using a validated questionnaire. The prevalence of overweight/obesity was 21.9% for boys and 14.8% for girls. Some 13.4% of boys and 10.2% of girls, respectively, had high blood pressure (HBP). A strong and positive association was found between overweight and HBP. After adjustment for body mass index (BMI), total PA was inversely associated with BP. When all PA domains were entered simultaneously in a regression model, and after adjustment for BMI, only sport out of school was significantly and inversely associated with systolic BP [β: -0.82 (-1.50; -0.13)]. These findings open avenue for the early prevention of HBP by the prevention of obesity and promotion of PA.