To report sex- and age-specific physical fitness levels in European adolescents.
A sample of 3428 adolescents (1845 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, ...Germany, Greece (an inland city and an island city), Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence study between 2006 and 2008. The authors assessed muscular fitness, speed/agility, flexibility and cardiorespiratory fitness using nine different fitness tests: handgrip, bent arm hang, standing long jump, Bosco jumps (squat jump, counter movement jump and Abalakov jump), 4×10-m shuttle run, back-saver sit and reach and 20-m shuttle run tests.
The authors derived sex- and age-specific normative values for physical fitness in the European adolescents using the LMS statistical method and expressed as tabulated percentiles from 10 to 100 and as smoothed centile curves (P₅, P₂₅, P₅₀, P₇₅ and P₉₅). The figures showed greater physical fitness in the boys, except for the flexibility test, and a trend towards increased physical fitness in the boys as their age increased, whereas the fitness levels in the girls were more stable across ages.
The normative values hereby provided will enable evaluation and correct interpretation of European adolescents' fitness status.
Background: Adequate sleep is a critical factor for adolescent's health and health-related behaviors. Objective: (a) to describe sleep duration in European adolescents from nine countries, (b) to ...assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association. Design: A sample of 3311 adolescents (1748 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire). Results: Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept 8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters. Conclusions: In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.
The authors' aim in this cross-sectional study was to characterize levels of objectively measured physical activity and sedentary time in adolescents from 9 European countries. The study comprised ...2,200 European adolescents (1,184 girls) participating in the HELENA cross-sectional study (2006-2008). Physical activity was measured by accelerometry and was expressed as average intensity (counts/minute) and amount of time (minutes/day) spent engaging in moderate- to vigorous-intensity physical activity (MVPA). Time spent in sedentary behaviors was also objectively measured. Cardiorespiratory fitness was measured by means of the 20-m shuttle run test. Level of maternal education was reported by the adolescents. A higher proportion of boys (56.8% of boys vs. 27.5% of girls) met the physical activity recommendations of at least 60 minutes/day of MVPA. Adolescents spent most of the registered time in sedentary behaviors (9 hours/day, or 71% of the registered time). Both average intensity and MVPA were higher in adolescents with high cardiorespiratory fitness, and sedentary time was lower in the high-fitness group. There were no physical activity or sedentary time differences between maternal education categories. These data provide an objective measure of physical activity and amount of time spent in sedentary behaviors in a relatively large number of European adolescents.
Objective: To describe the standardization process and reliability of anthropometric and bioelectrical impedance analysis (BIA) measurements. We examined both intra- and interobserver errors for ...skinfolds, circumferences and BIA. Methods: For the intraobserver error assessment, first of all, 202 adolescents in the pilot study (110 boys, 92 girls, aged 13.64+/-0.78 years) were assessed. For the second intraobserver and interobserver assessments, 10 adolescents were studied (5 boys and 5 girls). Results: The pilot study's intraobserver technical errors of measurement (TEMs) were between 0.12 and 2.9 mm for skinfold thicknesses, and between 0.13 and 1.75 cm for circumferences. Intraobserver reliability for skinfold thicknesses was greater than 69.44% and beyond 78.43% for circumferences. The final workshop's intraobserver TEMs for skinfold thicknesses and circumferences were smaller than 1; for BIA resistance TEMs were smaller than 0.1 omega and for reactance they were smaller than 0.2 omega. Intraobserver reliability values were greater than 95, 97, 99 and 97% for skinfold thicknesses, circumferences, BIA resistance and reactance, respectively. Interobserver TEMs for skinfold thicknesses and circumferences ranged from 1 to 2 mm; for BIA they were 1.16 and 1.26 omega for resistance and reactance, respectively. Interobserver reliability for skinfold thicknesses and circumferences were greater than 90%, and for BIA resistance and reactance they were greater than 90%. Conclusions: After the results of the pilot study, it was necessary to optimize the quality of the anthropometric measurements before the final survey. Significant improvements were observed in the intraobserver reliabilities for all measurements, with interobserver reliabilities being higher than 90% for most of the measurements. The Healthy Lifestyle in Europe by Nutrition in Adolescence Study aims to describe total body fat percentage and anthropometric indices of body fat distribution in European adolescents.
L’activité physique représente 25 à 30 % de la dépense énergétique totale. La part de la dépense énergétique liée à l’activité physique est modulable et varie selon la quantité d’activité physique. ...La mesure de la quantité d’activité physique est utile dans de nombreuses situations normales ou pathologiques chez l’enfant et l’adolescent. Plusieurs outils existent pour mesurer la quantité d’activité physique. Les questionnaires demeurent les plus utilisés en raison de leur faible coût et de leur facilité de mise en place, cependant ils surestiment systématiquement l’activité physique réelle. La technique de la fréquence cardiaque nécessite des calibrations individuelles en laboratoire et celle-ci peut être augmentée dans des circonstances (stress, température…) autres que l’augmentation de l’activité physique. Le podomètre mesure le nombre de pas, mais ne permet pas de quantifier les profils d’activité physique. L’accélérométrie mesure les mouvements (accélérations et décélérations) du sujet. Cette mesure objective et précise peut être utilisée dans les conditions normales de vie pour un faible coût. Le choix de l’outil dépend essentiellement des objectifs recherchés par le clinicien ou le chercheur.
Physical activity accounts for 25–30 % of total daily energy expenditure. Total energy expenditure varies according to the physical activity, which can be voluntarily modulated. Assessment of physical activity is therefore an important factor in the promotion of health and in several childhood and adolescent pathological situations. Questionnaires are widely used for assessing physical activity patterns in youth because of their low cost and ease of use, but they systematically overestimate physical activity. Heart rate monitoring requires individual calibration in the laboratory and a number of factors other than physical activity can affect heart rate (i.e., stress, temperature, etc.). Pedometers are objective devices but give only information on the number of steps and do not assess physical activity patterns. Accelerometers seem the best compromise between feasibility and validity in the assessment of physical activity in children in free-living conditions because this is an objective and accurate method whose cost is low. The choice of the type of device depends on the objectives of the clinician or researcher.
Objective: To examine the reliability of a set of health-related physical fitness tests used in the European Union-funded Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study on ...lifestyle and nutrition among adolescents. Design: A set of physical fitness tests was performed twice in a study sample, 2 weeks apart, by the same researchers. Participants: A total of 123 adolescents (69 males and 54 females, aged 13.6+/-0.8 years) from 10 European cities participated in the study. Measurements: Flexibility, muscular fitness, speed/agility and aerobic capacity were tested using the back-saver sit and reach, handgrip, standing broad jump, Bosco jumps (squat jump, counter movement jump and Abalakov jump), bent arm hang, 4 x 10 m shuttle run, and 20-m shuttle run tests. Results: The ANOVA analysis showed that neither systematic bias nor sex differences were found for any of the studied tests, except for the back-saver sit and reach test, in which a borderline significant sex difference was observed (P=0.044). The Bland-Altman plots graphically showed the reliability patterns, in terms of systematic errors (bias) and random error (95% limits of agreement), of the physical fitness tests studied. The observed systematic error for all the fitness assessment tests was nearly 0. Conclusions: Neither a learning nor a fatigue effect was found for any of the physical fitness tests when repeated. The results also suggest that reliability did not differ between male and female adolescents. Collectively, it can be stated that the reliability of the set of physical fitness tests examined in this study is acceptable. The data provided contribute to a better understanding of physical fitness assessment in young people.
Objective: To describe the development of a European computerized 24-h dietary recall method for adolescents, and to investigate the feasibility of self-administration (self report) by comparison ...with administration by a dietician (interview). Methods: Two hundred and thirty-six adolescents (mean age 14.6 years (s.d.=1.7)) of eight European cities completed the 24-h recall (Young Adolescents Nutrition Assessment on Computer (YANA-C)) twice (once by self-report and once by interview). Results: A small but significant underestimate in energy (61 (s.e.=31) kcal) and fat (4.2 (s.e.=1.7) g) intake was found in the self-reports in comparison with the interviews; no significant differences were found for the intake of carbohydrates, proteins, fibre, calcium, iron and ascorbic acid. Spearman's correlations were highly significant for all nutrients and energy ranging between 0.86 and 0.91. Agreement in categorizing the respondents as consumers and non-consumers for the 29 food groups was high (kappa statistics >or=0.73). Percentage omissions were on average 3.7%; percentage intrusions: 2.0%. Spearman's correlations between both modes were high for all food groups, for the total sample (>or=0.76) as well as for the consumers only (>or=0.72). Analysing the consumer only, on an average 54% of the consumed amounts were exactly the same; nevertheless, only for one group 'rice and pasta' a significant difference in consumption was found. Conclusion: Adaptation, translation and standardization of YANA-C make it possible to assess the dietary intake of adolescents in a broad international context. In general, good agreement between the administration modes was found, the latter offering significant potential for large-scale surveys where the amount of resources to gather data is limited.
In this paper we analyze different forms of fractional relaxation equations of order ν ∈ (0, 1), and we derive their solutions in both analytical and probabilistic forms. In particular, we show that ...these solutions can be expressed as random boundary crossing probabilities of various types of stochastic process, which are all related to the Brownian motion B. In the special case ν = ½, the fractional relaxation is shown to coincide with Pr{sup0≤s≤t
B(s) < U} for an exponential boundary U. When we generalize the distributions of the random boundary, passing from the exponential to the gamma density, we obtain more and more complicated fractional equations.
Rationale: Research involving humans is regulated by regulatory authorities through their specific requirements and controls. The Healthy Life Style in Europe by Nutrition in Adolescence ...Cross-Sectional Study (HELENA-CSS) is a multicenter biomedical research study of adolescents in several representative European cities, which requires satisfying medico-regulatory requirements including Independent Ethics Committee (IEC) approval and agreement by the national or local regulatory authorities. To achieve a high level of quality assurance relating to ethical issues, we followed the good clinical practices (GCP) described at the International Conference on Harmonisation (ICH), which we adapted to the national and local situations of each of the 11 participating cities in 10 European countries. Objective: The main objective of the HELENA-CSS is to evaluate reliable and comparable data of nutritional habits and lifestyle in a representative sample of European adolescents. The aim of this paper is to present the methods relating to the ethical and regulatory issues of this study and to describe the current state of the medico-regulatory requirements involved in conducting this kind of study in each country. Materials and Methods: Following the GCP-ICH guidelines, a protocol describing the HELENA-CSS was written and approved by all partners. In the pilot study, a case report form adapted to the study objectives and its manual of operation was constructed and used by all partners. All information letters to adolescents and their parents and consent forms were first written in English, then translated into the local language, and adapted to each local situation. All documents were then checked centrally for any deviation and corrected if required. An operation manual relating to ethical issues and other medico-regulatory requirements was also developed. This paper presents the current status of the medico-regulatory requirements from each HELENA-CSS participant country. Results: Before the beginning of the study, most centers had satisfied the medico-regulatory requirements of IEC approval and agreement with other national or local regulatory authorities/organizations. For a few centers, some problems were detected and corrective actions were taken to improve missing information to reach a high level of quality assurance of ethical issues. Conclusion: The GCP-ICH guidelines about nontherapeutic biomedical research are interpreted and applied differently across Europe. This study shows that high-quality nontherapeutic biomedical research can address the ethical issues included in the GCP-ICH regulations and can be harmonized among the HELENA European partners.
PDF
