One-week sleep hygiene education improves episodic memory in young but not in older adults during social isolation.

Memory formation is a dynamic process that comprises different phases, such as encoding, consolidation and retrieval. It could be altered by several factors such as sleep quality, anxiety, and depression levels. In the last years, due to COVID-19 pandemic, there was a reduction in sleep quality, an increase in anxiety and depressive symptoms as well as an impairment in emotional episodic memory encoding, especially in young adults. Taking into account the profound impact of sleep quality in daily life a series of rules has been developed that are conducive to consistently achieving good sleep, known as sleep hygiene education. These interventions have been shown to be effective in improving sleep quality and duration and reducing depressive and anxiety symptoms. Here we propose the implementation of a brief sleep hygiene education to improve sleep quality and memory performance as well as to diminish anxiety and depressive scores. For that, participants were divided into two groups: Sleep hygiene education and control group. After that, they were evaluated for anxiety, depression, and sleep quality levels and trained on an episodic memory task. They were tested immediately after (short-term test) and also 1 week later (long-term test). This procedure was also performed before the sleep hygiene education and was taken as baseline level. We found that episodic memory performance for young adults improved for the SHE group after intervention but not for older adults, and no improvements in emotional variables were observed. Despite not observing a significant effect of the intervention for young and older adults regarding the sleep quality scores, we consider that there may be an improvement in sleep physiology that is not subjectively perceived, but would also have a positive impact on memory processes. These results show that even a sleep hygiene education of 1 week could improve cognition in young adults when acute memory and sleep impairment occurs, in this case, due to the isolation by COVID-19 pandemic. However, we suggest that longer interventions should be implemented for older adults who already experience a natural decline in cognitive processes such as episodic memory formation.

Train at home, but not alone: a randomised controlled multicentre trial assessing the effects of live-streamed tele-exercise during COVID-19-related lockdowns.

OBJECTIVE: Public life restrictions associated with the COVID-19 pandemic caused reductions in physical activity (PA) and decreases in mental and somatic health. Considering the interplay between these factors, we investigated the effects of digital home exercise (DHE) during government-enforced lockdowns. METHODS: A multicentre randomised controlled trial was performed allocating healthy individuals from nine countries (N=763; 523 female) to a DHE or an inactive control group. During the 4-week main intervention, DHE members engaged in live-streamed multicomponent home exercise. Subsequently, both groups had access to prerecorded workouts for an additional 4 weeks. Outcomes, assessed weekly, included PA level (Nordic Physical Activity Questionnaire-Short), anxiety (Generalized Anxiety Disorder Scale-7), mental well-being (WHO-5 Questionnaire), sleep quality (Medical Outcome Study Sleep Scale), pain/disability (Chronic Pain Grade Scale) and exercise motivation (Self-Concordance Scale). Mixed models were used for analysis. RESULTS: Live-streamed DHE consistently increased moderate PA (eg, week 1: 1.65 times more minutes per week, 95% CI 1.40 to 1.94) and vigorous PA (eg, week 1: 1.31 times more minutes per week, 95% CI 1.08 to 1.61), although the effects decreased over time. In addition, exercise motivation, sleep quality and anxiety were slightly improved for DHE in the 4-week live streaming period. The same applied to mental well-being (mean difference at week 4: +0.99, 95% CI 0.13 to 1.86), but an inverted trend was observed after live streaming was substituted by prerecorded exercise. CONCLUSIONS: Live-streamed DHE represents an efficacious method to enhance PA and selected markers of health during pandemic-related public life restrictions. However, research on implementation is warranted to reduce dropout rates. TRIAL REGISTRATION NUMBER: DRKS00021273.

Drastic Reductions in Mental Well-Being Observed Globally During the COVID-19 Pandemic: Results From the ASAP Survey.

Most countries affected by the COVID-19 pandemic have repeatedly restricted public life to control the contagion. However, the health impact of confinement measures is hitherto unclear. We performed a multinational survey investigating changes in mental and physical well-being (MWB/PWB) during the first wave of the pandemic. A total of 14,975 individuals from 14 countries provided valid responses. Compared to pre-restrictions, MWB, as measured by the WHO-5 questionnaire, decreased considerably during restrictions (68.1 ± 16.9 to 51.9 ± 21.0 points). Whereas 14.2% of the participants met the cutoff for depression screening pre-restrictions, this share tripled to 45.2% during restrictions. Factors associated with clinically relevant decreases in MWB were female sex (odds ratio/OR = 1.20, 95% CI: 1.11-1.29), high physical activity levels pre-restrictions (OR = 1.29, 95% CI 1.16-1.42), decreased vigorous physical activity during restrictions (OR = 1.14, 95% CI: 1.05-1.23), and working (partially) outside the home vs. working remotely (OR = 1.29, 95% CI: 1.16-1.44/OR = 1.35, 95% CI: 1.23-1.47). Reductions, although smaller, were also seen for PWB. Scores in the SF-36 bodily pain subscale decreased from 85.8 ± 18.7% pre-restrictions to 81.3 ± 21.9% during restrictions. Clinically relevant decrements of PWB were associated with female sex (OR = 1.62, 95% CI: 1.50-1.75), high levels of public life restrictions (OR = 1.26, 95% CI: 1.18-1.36), and young age (OR = 1.10, 95% CI: 1.03-1.19). Study findings suggest lockdowns instituted during the COVID-19 pandemic may have had substantial adverse public health effects. The development of interventions mitigating losses in MWB and PWB is, thus, paramount when preparing for forthcoming waves of COVID-19 or future public life restrictions.

A Pandemic within the Pandemic? Physical Activity Levels Substantially Decreased in Countries Affected by COVID-19.

Governments have restricted public life during the COVID-19 pandemic, inter alia closing sports facilities and gyms. As regular exercise is essential for health, this study examined the effect of pandemic-related confinements on physical activity (PA) levels. A multinational survey was performed in 14 countries. Times spent in moderate-to-vigorous physical activity (MVPA) as well as in vigorous physical activity only (VPA) were assessed using the Nordic Physical Activity Questionnaire (short form). Data were obtained for leisure and occupational PA pre- and during restrictions. Compliance with PA guidelines was calculated based on the recommendations of the World Health Organization (WHO). In total, n = 13,503 respondents (39 ± 15 years, 59% females) were surveyed. Compared to pre-restrictions, overall self-reported PA declined by 41% (MVPA) and 42.2% (VPA). Reductions were higher for occupational vs. leisure time, young and old vs. middle-aged persons, previously more active vs. less active individuals, but similar between men and women. Compared to pre-pandemic, compliance with WHO guidelines decreased from 80.9% (95% CI: 80.3-81.7) to 62.5% (95% CI: 61.6-63.3). Results suggest PA levels have substantially decreased globally during the COVID-19 pandemic. Key stakeholders should consider strategies to mitigate loss in PA in order to preserve health during the pandemic.

Restrictercise! Preferences Regarding Digital Home Training Programs during Confinements Associated with the COVID-19 Pandemic.

Confinement measures during the COVID-19 pandemic have caused substantial reductions in global physical activity (PA) levels. In view of the manifold health benefits of PA, the development of interventions counteracting this trend is paramount. Our survey with 15,261 participants (38 ± 15 years, 58.5% females) examined preferences towards digital home exercise programs in 14 countries affected by COVID-19. More than two-thirds of the sample (68.4%, n = 10,433) indicated being interested in home exercise, and most participants were willing to work out at least three times per week (89.3%, n = 9328). Binary logistic regression revealed that female sex, working part-time, younger age, and being registered in a gym were associated with willingness to exercise. Flexibility (71.1%, n = 7377), resistance (68.6%, n = 7116), and endurance training (62.4%, n = 6478) were the most preferred types of exercise. Our results may guide health providers in developing individually tailored PA interventions during the current and future pandemics.

Intensidades de actividad física en juegos estructurados y activos en niños entre 6 y 12 años / Intensities of Physical Activity in Structured and Active Games in Children between 6 and 12 Years / Intensidades de atividade física em jogos estruturados e ativos em crianças entre 6 e 12 anos

Resumen Introducción: Muchos niños no alcanzan las recomendaciones internacionales respecto a los niveles de actividad física (AF) relacionados con la salud. El juego estructurado y activo sería una gran estrategia para incrementar la AF. El objetivo fue describir intensidades de AF alcanzadas en juegos estructurados seleccionados, y su relación con la recomendación de AF para niños. Materiales y métodos: Participaron 30 niños normopeso (20 varones y 10 mujeres), de estos grupos etarios: 6-7, 8-9 y 10-12 años. Realizaron 32 juegos de 6 min 50 s (± 1 min 42 s) de duración cada uno, en seis sesiones, y con pausas de 5-6 min interjuegos. La intensidad de AF fue determinada por observación sistemática (SOFIT) y acelerometría, categorizando la intensidad de AF según puntos de corte en cuentas por minuto (CPM). Se calcularon medias y DS para variables de acelerometría, CPM y SOFIT. Se realizaron contrastes entre sexos y grupos etarios, considerando el grupo total y por cada juego. Se correlacionaron variables de acelerometría con las de SOFIT. La significancia fue p <0,05. Resultados: Diez juegos pertenecen a AF moderada y 22, al límite superior de ligera. Hubo diferencias significativas, para CPM, entre 8-9 y 6-7 años, y entre sexos, en cinco juegos. Se correlacionó AF moderada y vigorosa y CPM (r = 0,36; p = 0,04). Conclusiones: Estos juegos, respecto a intensidad de AF (10 en categoría moderada y 22 en límite superior de ligera), revelan un aporte sustantivo a las recomendaciones de AF para niños.

Abstract Introduction: Many children do not reach recommendations regarding physical activity (PA) levels related to health. Structured and active games would be a great strategy to increase PA levels. The aim was to describe intensities of PA reached in selected structured games and their relation with PA recommendations for children. Material and methods: Participants were thirty normal-weight children (twenty boys and ten girls). The age groups were 6-7, 8-9, and 10-12 years. They performed 32 games of 6 min 50 s (± 1 min 42 s of duration each), in 6 sessions, and with pauses of 5-6 min between them. PA intensity was determined by systematic observation (SOFIT) and accelerometry, categorizing PA intensity according to cut-off points in counts per minute (CPM). Means and DS were calculated for accelerometry variables, CPM, and SOFIT. The contrast was made between gender and age groups, considering the whole group and each game. Accelerometry variables were correlated with those of SOFIT. The significance was p <0.05. Results: Ten games belong to moderate PA, and 22 to the upper light limit. There were significant differences for CPM, between 8-9 and 6-7 years, and between gender, in five games. Moderate and vigorous PA and CPM were correlated (r = 0.36, p = 0.04). Conclusions: Regarding PA intensity, these games (ten in moderate category and 22 in the light upper limit), reveal a substantive contribution to the PA recommendations for children.

Resumo Introdução: Muitas crianças não alcançam as recomendações internacionais respeito aos níveis de atividade física (AF) relacionados com a saúde. O jogo estruturado e ativo seria uma grande estratégia para incrementar a AF. O objetivo foi descrever intensidades de AF alcançadas em jogos estruturados selecionados, e sua relação com a recomendação de AF para crianças. Materiais e métodos: Participaram 30 crianças com peso normal (20 homens e 10 mulheres), destes grupos etários: 6-7, 8-9 e 10-12 anos. Realizaram 32 jogos de 6 min 50 s (± 1 min 42 s) de duração cada um, em 6 sessões, e com pausas de 5-6 min interjogos. A intensidade de AF foi determinada por observação sistemática (SOFIT) e acelerometria, categorizando a intensidade de AF segundo pontos de corte em contas por minuto (CPM). Se realizaram contrastes entre sexos e grupos etários, considerando o grupo total e por cada jogo. Se correlacionaram variáveis de acelerometria com as de SOFIT. A significação foi p <0,05. Resultados: Dez jogos pertenecem a AF moderada, e 22 ao limite superior de ligeira. Houve diferenças significativas, para CPM, entre 8-9 e 6-7 anos, e entre sexos, em 5 jogos. Se correlacionou AF moderada e vigorosa e CPM (r = 0,36; p = 0,04). Conclusões: Estes jogos, respeito à intensidade de AF (10 em categoria moderada, e 22 em limite superior de ligeira), revelam um aporte substantivo às recomendações de AF para crianças.

[Physical activity and health habits in Argentinian undergraduates]. / Actividad física y hábitos de salud en estudiantes universitarios argentinos.

OBJECTIVE: Deterioration of healthy habits in young people, particularly undergraduates, justifies their study in these populations. The aim of the present research is to analyze physical activity levels of students from the Universidad Nacional de La Matanza (Argentina), trying to describe homogeneous groups by demographic characteristics, health habits and perceived wellbeing, and to identify the level of physical activity that best describes each of the groups. METHODOLOGY: Participants were 554 students (281 males and 273 females) of different careers which were applied the Global Physical Activity Questionnaire (GPAQ), and a survey related to health habits, perception of happiness and other demographic variables. Measures of central tendency and variability, and percentiles P25 and P75, were calculated for all variables. Segmentation was performed using hierarchical cluster analysis, after a previous factor analysis. RESULTS: 79.8% of students, and 97.2% of Physical Education students met the recommendations of physical activity. Students identified with a high physical activity level were those who attended in day shift, did not smoke, did not consume alcohol or drugs, did not work, had no children or stable partner, and with a medium socio-economic level. CONCLUSIONS: It is suggested the need for a strong educational intervention by universities to promote healthy habits and regular performance of physical activity, as they have a primary social responsibility regarding these issues.

Objetivo: El deterioro de los hábitos saludables en los jóvenes, particularmente universitarios, justifica su investigación en dichas poblaciones. El objetivo del presente estudio es analizar los niveles de actividad física en estudiantes de la Universidad Nacional de La Matanza (Argentina), intentando describir grupos homogéneos según características demográficas, de hábitos de salud y de percepción de bienestar, e identificando el nivel de actividad física que mejor describa a cada uno de los grupos. Metodología: Participaron 554 estudiantes (281 varones y 273 mujeres) de distintas carreras a los que se aplicó el Cuestionario Global de Actividad Física (GPAQ) y un instrumento sobre hábitos de salud, percepción de felicidad y diversas variables demográficas. Se calcularon medidas de tendencia central y variabilidad, así como los percentiles P25 y P75, para todas las variables. Se realizó una segmentación mediante análisis de clusters jerárquico, con un análisis de factores previo. Resultados: El 79,8% de los estudiantes, y el 97,2% de aquellos que cursaban Educación Física cumplían con las recomendaciones de realización de actividad física. Los alumnos que se identificaban con un nivel de actividad física alto eran los que cursaban en turno diurno, no consumían tabaco, alcohol ni drogas, no trabajaban, no tenían hijos ni pareja estable, y poseían un nivel socio- económico medio. Conclusiones: Se sugiere la necesidad de una sólida intervención educativa por parte de las universidades para fomentar hábitos saludables y la realización regular de actividad física, ya que tienen una responsabilidad social primaria respecto a estas problemáticas.

Actividad física, comportamiento sedentario y estado nutricional en escolares de la ciudad de Buenos Aires / Physical activity, sedentary behavior and nutritional status in schoolchildren in the city of Buenos Aires

Introducción: la obesidad en niños y adolescentes se relaciona con la disminución de la actividad física y el estilo de vida sedentario. El objetivo de este trabajo ha sido determinar estado nutricional, niveles de actividad física y sedentarismo en un grupo de escolares y estudiantes secundarios de clase media baja y media alta de la Ciudad Autónoma de Buenos Aires utilizando acelerometría. Población y métodos: entre agosto y diciembre de 2013 se estudiaron 174 sujetos, 87 varones y 87 mujeres, de 7 a 17 años, 40,8% asistente a escuelas de nivel primario y 59,2% al nivel secundario; 44,3% de nivel socioeconómico medio alto y 55,7% medio bajo. Se estudió edad, sexo, peso, talla, nivel de actividad física y tiempo sedentario. Los sujetos portaron por siete días un acelerómetro uniaxial CSA 7164. Se utilizó el coeficiente correlación de Pearson y test t al comparar actividad física y tiempo sedentario por edad y sexo. Resultados: en el nivel socioeconómico medio-bajo, el 34,0% presentó sobrepeso y el 21,6% obesidad, en el medio-alto el 14,3% y 5,2%. La actividad física promedio fue de 31,5 minutos (±19,7) y 552,05 (±126,9) los minutos de comportamiento sedentario. La actividad física realizada por niños, 37,07 minutos (±20,0) fue significativamente mayor que en adolescentes (27,28 minutos; ±18,5). El tiempo sedentario fue significativamente mayor en adolescentes, 621,37 minutos (±106,1) que en niños (460,78 minutos; ±89,0). Tanto en niños como en adolescentes, los varones registraron mayor actividad física que las mujeres. No hubo diferencias significativas en tiempo sedentario. Conclusiones: es elevado el sobrepeso y la obesidad, siendo mayor en el nivel socioeconómico medio-bajo. La mayoría de la muestra no alcanzó las recomendaciones de actividad física, y el tiempo de conducta sedentaria fue elevado.

Introduction: obesity in children and adolescents is associated with decreased physical activity and sedentary lifestyle. The aim of this study was to determine nutritional status, levels of physical activity and inactivity in a group of children and high school students from average lower middle and high middle classes in the city of Buenos Aires by accelerometry. Population and methods: 174 subjects, 87 males and 87 females, aged 7 to 17 years old, 40,8% attending primary schools and 59,2% attending high school were studied between August and December 2013; 44,3% of subjects with high socioeconomic status, and 55,7% average. Age, sex, weight, height, level of physical activity and sedentary time were studied. Subjects carried the CSA 7164 uniaxial accelerometer device or seven days. The Pearson correlation coefficient and t test were used to compare physical activity and sedentary time by age and sex. Results: in the middle-low socioeconomic status, 34,0% were overweight and 21,6% obese, in the middle-high 14,3% and 5,2% respectively. The average physical activity was 31,5 minutes (±19,7) and sedentary behavior 552,05 (±126,9) minutes. The physical activity of children, 37,07 minutes (±20,0) was significantly higher than in adolescents, 27,28 minutes (±18,5). Sedentary time was significantly greater in adolescents, 621,37 minutes (±106,1) than in children, 460,78 minutes (±89,0). Both school and adolescent boys reported more physical activity than women did. No significant differences in sedentary time were observed. Conclusions: high overweight and obesity, are higher in the medium-low socioeconomic status. The majority of samples did not meet the recommendations for physical activity and sedentary behavior time was high.

El peso transportado en las mochilas escolares: Un estudio en cuatro escuelas de la región metropolitana de Buenos Aires, Argentina / A study concerning how much weight schoolchildren carry in their bags, involving four schools in the metropolitan area of Buenos Aires, Argentina

RESUMEN Objetivo Determinar el peso transportado del equipaje escolar (en valores absolutos y relativos) y la distancia caminada en los trayectos hogar-escuela, en escolares de cuatro escuelas de la región metropolitana de Buenos Aires. Métodos Se estudiaron 751 alumnos (394 varones y 357 mujeres, de 9 a 18 años) de niveles primario (4to. a 6to. grados), y secundario (1ro. a 3er. años) de tres escuelas de gestión privada y una pública. Se midieron los pesos corporal y del equipaje escolar, y se indagó sobre la distancia desde la escuela al hogar, y sobre las cuadras caminadas en este trayecto. Se realizó un análisis descriptivo y contrastes según género, nivel educativo, tipo de escuela y grados y años cursados. Se verificaron posibles asociaciones entre variables. Se dividió al grupo en dos: quienes transportaban menos del 10 % de su peso corporal, y los que acarreaban el 10 % (considerado como valor crítico) y más, calculándose las frecuencias según tipo de equipaje utilizado. Resultados El 68 % de los evaluados transporta un peso por encima del 10 % del peso corporal (P42=10,13 %), siendo del 66 % para varones (P44 = 10,12 %) y 60 % para mujeres (P40=10,2 %). En escuelas privadas se acarrearon mayores pesos que en públicas (p<0,05); y en ambos niveles educativos los alumnos de cursos inferiores transportaron pesos superiores que los de grados superiores (p<0,05). Conclusiones La mayoría de los alumnos transporta pesos relativos por encima de las recomendaciones, siendo las mujeres las más perjudicadas. Los más pequeños cargan pesos absolutos y relativos mayores.

ABSTRACT Objective Determining the weight children carry in their bags to school (absolute and relative values) and the distance walked during home-school routes, involving students from four schools in the metropolitan area of Buenos Aires. Method The study involved 751 primary (4th to 6th grades) and secondary (1st to 3rd years) level students who were attending three private schools and one public one. Body and bag weights were measured and the children were asked about the distance (in blocks) they walked from school to home. The study involved a descriptive analysis and contrasted the students by gender, educational level, type of school and grade or year. Possible associations between variables were ascertained. The group was divided into those carrying bags weighing less than 10% of their body weight and those who carrying 10% (considered a critical value) and more; frequencies were calculated by the type of bag being used. Results 68% of the sample were carrying 10% or more of their body weight (P42=10.13%): 66% in male (P44=10.12%) and 60% in female children (P40=10.2%). Private school students carried more weight than public school children (p<0.05) and younger students carried a greater weight than older students (p<0.05) in both educational levels. Conclusions Most children were carrying relative weights well above that recommended and female students were most affected. Younger students carried higher absolute and relative weights.

[A study concerning how much weight schoolchildren carry in their bags, involving four schools in the metropolitan area of Buenos Aires, Argentina]. / El peso transportado en las mochilas escolares: Un estudio en cuatro escuelas de la región metropolitana de Buenos Aires, Argentina

OBJECTIVE: Determining the weight children carry in their bags to school (absolute and relative values) and the distance walked during home-school routes, involving students from four schools in the metropolitan area of Buenos Aires. METHOD: The study involved 751 primary (4th to 6th grades) and secondary (1st to 3rd years) level students who were attending three private schools and one public one. Body and bag weights were measured and the children were asked about the distance (in blocks) they walked from school to home. The study involved a descriptive analysis and contrasted the students by gender, educational level, type of school and grade or year. Possible associations between variables were ascertained. The group was divided into those carrying bags weighing less than 10% of their body weight and those who carrying 10% (considered a critical value) and more; frequencies were calculated by the type of bag being used. RESULTS: 68% of the sample were carrying 10% or more of their body weight (P42=10.13%): 66% in male (P44=10.12%) and 60% in female children (P40=10.2%). Private school students carried more weight than public school children (p<0.05) and younger students carried a greater weight than older students (p<0.05) in both educational levels. CONCLUSIONS: Most children were carrying relative weights well above that recommended and female students were most affected. Younger students carried higher absolute and relative weights.

Actividad física y conducta sedentaria en estudiantes terciarios y niversitarios de la Región Metropolitana de Buenos Aires (Argentina) / Physical activity and sedentary behavior in tertiary and university students of Metropolitan Area of Buenos Aires (Argentina)

Os comportamentos de saúde dos estudantes universitários são de particular interesse não só para o bem-estar dos próprios alunos, mas também porque uma vez graduados poderia atuar como modelos em seus ambientes profissionais e pessoais. Na Argentina, o registro é escassa e dispersa. Os objetivos deste estudo são analisar os níveis de atividade física e comportamentos sedentários em estudantes universitários da nossa região, e também ver se existem diferenças entre estudantes de carreiras relacionadas à atividade física e estudantes de outras carreiras. Nós examinamos o nível de atividade física e comportamentos sedentários em uma amostra de estudantes universitários de ambos os sexos de 17 a 35 anos na Região Metropolitana de Buenos Aires (n=2131) através de um questionário validado internacionalmente chamado Global Physical Activity Questionnaire. Alunos de cursos de graduação relacionados com a actividade física tiveram um nível significativamente mais elevado de atividade e comportamentos sedentários significativamente mais baixos do que os estudantes de outros cursos de graduação. 19% dos homens e 30% das alunas de outros cursos de graduação tiveram um baixo nível de atividade física, considerados insuficientes para promover a saúde. Em ambos os grupos de homens alunos eram mais ativos que as mulheres, não houve diferenças significativas entre os sexos em comportamentos sedentários. O subgrupo de mulheres estudantes em cursos de graduação não relacionados à atividade física foi o único que tinha o perfil menos favorável da actividade física e comportamentos sedentários. O domínio dos transportes parece ser o mais sensível e apropriada para o desenvolvimento de estratégias de intervenção em atividade física e comportamento sedentário nesta população.

Health behaviors of college students are of particular interest not only for the wellbeing of students themselves but also because once graduates could act as role models in their professional andpersonal environments. In Argentina, antecedents are sparse and scattered. The aims of this work are to survey physical activity and sedentary behavior levels in university and tertiary students in our region, and also see if there are differences among students of courses related to physical activity and students of other courses. It was surveyed the level of physical activity and sedentary behaviors in a sample of tertiary and university students of both sexes from 17 to 35 years of age in the Metropolitan Region of Buenos Aires (n = 2131) through the Global Physical Activity Questionnaire which is an internationally validated recall questionnaire. Students of courses related to physical activity had a significantly higher level of activity and a significantly lower level of sedentary behaviors than students in other courses. 19% of male and30% of female students from other courses had a low physical activity level, considered insufficient to promote health. In both groups, male students were more active than female, and there were no significant differences between sexes in sedentary behaviors. The subgroup of female students in courses not related to physical activity was the one who had the less favourable profile of physical activity and sedentary behaviors. The transport domain seems to be the most susceptible and suitable for developing intervention strategies in physical activity and sedentary behavior in this population.

Metabolic and functional responses playing tennis on different surfaces.

The purpose of this study was to compare various metabolic and functional responses while playing tennis on clay and hard courts. Twelve 90-minute matches were played (6 on clay courts and 6 on hard courts) by 4 nationally ranked players. During the on-court tests, oxygen uptake (VO2) and heart rate (HR) were measured using portable systems. Capillary blood lactate concentration (LA) was measured every 10 minutes. Additionally, distance ran, playing time, resting time, and exercise to rest ratio were monitored by time-motion analysis. The statistical analysis showed that playing time was higher on clay courts than on hard courts (p < 0.05), and resting time on clay courts and hard courts was not statistically different (p > 0.05). The exercise to rest ratio was affected by the interaction between playing time and resting time, showing a longer recovery time per unit of exercise on hard courts than on clay courts (p < 0.05). Distance ran, mean HR, and mean LA were significantly higher on clay courts than on hard courts (p < 0.05). There was less fluctuation of the VO2 response on clay courts than on hard courts. Therefore, it is suggested that conditioning programs should be adjusted according to the playing surface to account for the longer playing time, greater exercise to rest ratio, increased HR and LA, and a more steady pattern of VO2 seen on clay courts.

Aproximação ao estudo dos perfis de gasto energético em relação aos conteúdos e contextos, e à participaçãodocente, durante as aulas de educação física em escolas médias da cidade de Buenos Aires / Approximation to study the profiles of energy expenditure for content and context, and participation teacher, during school physical education in schools of the city of Buenos Aires

O objetivo deste trabalho foi realizar uma aproximação exploratória sobre os níveis de atividade física relacionados com os conteúdos-contexto e à participação docente, durante as aulasde educação física em escolas médias. Estudaram- se 152 homens e 52 mulheres, entre 13 e 18 anosde idade, que participaram de 21 aulas de educação física, utilizando um sistema de observação direta chamado S.O.F.I.T.(System for Observing Fitness Instruction Time). Estimou-se a taxa de gasto energético das aulas. Acharam-se medidas de tendência central e de variabilidade para cada variávelque cosntituem as três faces do instrumento (níveis de atividade física, conteúdos-contexto e participação docente). Determinou-se a influência de gênero dos alunos (mediante t-teste para grupos independentes) e do ano cursado (mediante teste de Kruskall- Wallis) sobre o restante das variáveis independentes. N.S.:p< 0,05. Não existiram diferenças significativas de gênero, exceto para o nível muito ativo dos homens. O ano que foi cursado influiu sobre atividades de aptidão física, habilidades motoras, jogo regrado, jogo livre e condução. Concluiu- se que: 1) O limiar mínimo de atividade física moderada a vigorosa satisfaz as recomendações internacionais. 2) A época de relevamento teria influência nos resultados. 3) Necessidade de extender esta investigação a uma amostra representativa. Estes descobrimentos têm implicâncias sobre o papel da aula de educação física como intervenção pedagógica e de saúde.

The aim was an exploratory work about levels of physical activity in relation to contents / contexts and teacher interactions during physical education classes, in high schools. We studied 152males and 52 females between 13 and 18 years who participated in 21 physical education classes, using a direct observation system called SOFIT (System for Observing Fitness Instruction Time). We estimated the energy expenditure rate of classes. We calculated central tendency and variability measures for each of one variables that explain the 3 phases of instrument (levels of physical activity,contents/contexts and teacher interactions). We fixed gender influence in pupils (through t- Test for independent groups) and the grade that the teen course (through Kruskall-Wallis test), over rest of dependent variables. N.S.: p< 0,05. We observed significant differences in gender except to very active level in males. Grade influence was determined over physical fitness activities, motor skills,game, free play and management. We conclude that: 1) minimal threshold of moderate to vigorous physical activity be in accord with international recommendations. 2) Survey time influences the results. 3) Need to extend this research to a representative sample. These findings have involve over the physical education classes like pedagogic and health interventions.