Learning from Outdoor Webcams: Surveillance of Physical Activity Across Environments

Abstract
Publicly available, outdoor webcams continuously view the world and share images. These cameras include traffic cams, campus cams, ski-resort cams, etc. The Archive of Many Outdoor Scenes (AMOS) is a project aiming to geolocate, annotate, archive, and visualize these cameras and images to serve as a resource for a wide variety of scientific applications. The AMOS dataset has archived over 750 million images of outdoor environments from 27,000 webcams since 2006. Our goal is to utilize the AMOS image dataset and crowdsourcing to develop reliable and valid tools to improve physical activity assessment via online, outdoor webcam capture of global physical activity patterns and urban built environment characteristics.
This project’s grand scale-up of capturing physical activity patterns and built environments is a methodological step forward in advancing a real-time, non-labor intensive assessment using webcams, crowdsourcing, and eventually machine learning. The combined use of webcams capturing outdoor scenes every 30 min and crowdsources providing the labor of annotating the scenes allows for accelerated public health surveillance related to physical activity across numerous built environments. The ultimate goal of this public health and computer vision collaboration is to develop machine learning algorithms that will automatically identify and calculate physical activity patterns.

Increased physical activity and fitness above the 50th percentile prevents the institutionalization of elderly people: a cross-sectional pilot study.

Introduction Institutionalization in a nursing home restricts autonomy, most notably free will, free choice, and free action. Decreased physical activity and fitness are predictive of disability and dependence (Rikli & Jones, 2013; Tak, Kuiper, Chorus, & Hopman-Rock, 2014); however little is known about the impact of these factors on institutionalization. Thus, this study aimed to analyze the impact of physical activity and fitness and on the risk of elderly people without cognitive impairment become institutionalized. Methods This cross-sectional study involved 195 non-institutionalized (80.14.4yrs) and 186 institutionalized (83.85.2yrs) participants. Cognitive impairment was assessed using Mini-Mental State Examination, physical activity was assessed using the International Physical Activity Questionnaire, and measures of physical fitness were determined by the Senior Fitness Test. Results: Multivariate binary logistic analysis selected 4 main predictors of institutionalization in both genders. The likelihood of becoming institutionalized increased by +18.6% for each additional year of age, while it decreased by -24.8% by each fewer kg/m2 in BMI, by -0.9% for each additional meter performed in the aerobic endurance test and by -2.0% for each additional 100MET-min/wk of physical activity expenditure (p<0.05). Values ≤50th percentile (age ≥81yrs, BMI≥26.7kg/m2, aerobic endurance ≤367.6m, and physical activity ≤693MET-min/wk) were computed using Receiver Operating Characteristics analysis as cut-offs discriminating institutionalized from non-institutionalized elderly people. Conclusion The performance of physical activity, allied to an improvement in physical fitness (mainly BMI and aerobic endurance) may prevent the institutionalization of elderly people without cognitive impairment only if they are above the 50th percentile; the following is highly recommend: expending ≥693MET-min/wk on physical activity, being ≤26.7kg/m2 on BMI, and being able to walk ≥367.6m in the aerobic endurance test, especially above the age of 80 years. The discovery of this trigger justifies the development of physical activity programs targeting the pointed cut-offs in old, and very old people. References Rikli, R., & Jones, C. (2013). Development and validation of criterion-referenced clinically relevant fitness standards for maintaining physical independence in later years. Gerontologist, 53, 255-267. Tak, E., Kuiper, R., Chorus, A., & Hopman-Rock, M. (2014). Prevention of onset and progression of basic ADL disability by physical activity in community dwelling older adults: a meta-analysis. Ageing Res Rev, 12, 329-338.

Relationship of milk intake and physical activity to abdominal obesity among adolescents

Background: Diet and physical activity (PA) are recognized as important factors to prevent abdominal obesity (AO), which is strongly associated with chronic diseases. Some studies have reported an inverse association between milk consumption and AO. Objective: This study examined the association between milk intake, PA and AO in adolescents. Methods: A cross-sectional study was conducted with 1209 adolescents, aged 15–18 from the Azorean Archipelago, Portugal in 2008. AO was defined by a waist circumference at or above the 90th percentile. Adolescent food intake was measured using a semi-quantitative food frequency questionnaire, and milk intake was categorized as ‘low milk intake’ (<2 servings per day) or ‘high milk intake’ ( 2 servings per day). PA was assessed via a self-report questionnaire, and participants were divided into active (>10 points) and low-active groups ( 10 points) on the basis of their reported PA. They were then divided into four smaller groups, according to milk intake and PA: (i) low milk intake/low active; (ii) low milk intake/active; (iii) high milk intake/low active and (iv) high milk intake/active. The association between milk intake, PA and AO was evaluated using logistic regression analysis, and the results were adjusted for demographic, body mass index, pubertal stage and dietary confounders. Results: In this study, the majority of adolescents consumed semi-skimmed or skimmed milk (92.3%). The group of adolescents with high level of milk intake and active had a lower proportion of AO than did other groups (low milk intake/low active: 34.2%; low milk intake/active: 26.9%; high milk intake/low active: 25.7%; high milk intake/active: 21.9%, P = 0.008). After adjusting for confounders, low-active and active adolescents with high levels of milk intake were less likely to have AO, compared with low-active adolescents with low milk intake (high milk intake/low active, odds ratio [OR] = 0.412, 95% confidence intervals [CI]: 0.201– 0.845; high milk intake/active adolescents, OR = 0.445, 95% CI: 0.235–0.845).Conclusion: High milk intake seems to have a protective effect on AO, regardless of PA level

Step based physical activity guidelines for preschool-aged children

Objective Public health organizations recommend that preschool-aged children accumulate at least 3 h of physical activity (PA) daily. Objective monitoring using pedometers offers an opportunity to measure preschooler's PA and assess compliance with this recommendation. The purpose of this study was to derive step-based recommendations consistent with the 3 h PA recommendation for preschool-aged children. Method The study sample comprised 916 preschool-aged children, aged 3 to 6 years (mean age = 5.0 ± 0.8 years). Children were recruited from kindergartens located in Portugal, between 2009 and 2013. Children wore an ActiGraph GT1M accelerometer that measured PA intensity and steps per day simultaneously over a 7-day monitoring period. Receiver operating characteristic (ROC) curve analysis was used to identify the daily step count threshold associated with meeting the daily 3 hour PA recommendation. Results A significant correlation was observed between minutes of total PA and steps per day (r = 0.76, p < 0.001). The optimal step count for ≥ 3 h of total PA was 9099 steps per day (sensitivity (90%) and specificity (66%)) with area under the ROC curve = 0.86 (95% CI: 0.84 to 0.88). Conclusion Preschool-aged children who accumulate less than 9000 steps per day may be considered Insufficiently Active.

Adaptação Cultural e Validação do Questionário: “Pregnancy Physical Activity Questionnaire” para a População Portuguesa

Introdução: A prática de atividade física tem vindo a ser incentivada por vários organismos nacionais e internacionais, visando a promoção de saúde. No entanto, não existe consenso em relação à influência e à intensidade ótima da atividade física durante a gravidez, tal facto pode dever-se à falta de instrumentos válidos que permitam a comparação entre os vários países do nível de atividade física das gestantes. Não foi identificado qualquer questionário válido que avaliasse a atividade física, durante a gravidez, para a população portuguesa. Objetivo: O objetivo deste estudo foi traduzir e adaptar o questionário PPAQ para a língua portuguesa e testar a fiabilidade e validade do mesmo. Métodos: A equivalência linguística foi obtida através da tradução e retrotradução e após a realização de um teste piloto a 6 mulheres grávidas. A fiabilidade foi obtida através do testereteste, com um intervalo de 7 dias, e analisada através do ICC, SEM e do método Bland Altman. A validade de critério foi testada, através dos resultados do PPAQ e do acelerómetro, pelo coeficiente de correlação de Pearson. Resultados: Os valores do ICC relativos à fiabilidade foram para o score total do PPAQ de 0,77, para as atividades sedentárias 0,87, para as atividade de baixa intensidade 0,76, para as atividades de intensidade moderada 0,76 e para as atividades de intensidade vigorosa 0,70. Na avaliação da validade obtivemos um valor de correlação de Pearson para atividade total de -0,030. Obtivemos correlação significante para as atividades de baixa intensidade (r=0,149; p=0,025), para as atividades de baixa intensidade em grávidas no 2º trimestre (r=0,256; p=0,010) e para as atividades de baixa intensidade e atividades vigorosas em mulheres no 3º trimestre gestacional (r=0,447; p=0,037 e r= 0,578; p=0,005, respetivamente). Conclusão: O PPAQ apresenta uma fiabilidade excelente e validade semelhante à versão original.

Atividade física e Saúde Pública : políticas e estratégias de ação intersectorial na promoção de health-enhancing physical activity (HEPA) em Portugal

RESUMO - INTRODUÇÃO: A promoção de health-enhancing physical activity (HEPA), entendida como atividade física para a saúde, revela-se um dos aspectos fulcrais do trabalho de ação intersectorial da saúde pública e um dos principais desafios atuais no combate a esta pandemia da inatividade física de consequências na saúde, económicas, ambientais e sociais. A inatividade física está identificada como sendo um dos fatores de risco que contribui largamente para a mortalidade global. Análises às abordagens políticas de promoção da atividade física para a saúde são importantes instrumentos de sistematização da informação relacionada com o estudo deste problema. OBJETIVOS: É objetivo deste estudo analisar políticas e estratégias de ação intersectorial na promoção da atividade física para a saúde em Portugal. Em específico, elencar e analisar: 1) principais políticas e estratégias atuais dos diferentes sectores; 2) consideração de qual é o papel do sector da saúde no assunto; 3) fatores-chave e critérios de sucesso para a implementação de políticas de promoção de HEPA. METODOLOGIA: Estudo qualitativo, descritivo e transversal, por meio de entrevistas semiestruturadas e abertas pelos sectores da saúde, educação, desporto, transportes/planeamento urbano e ação social; análise documental, relativamente aos últimos 3 anos, com análise de conteúdo quanto aos critérios de sucesso presentes. RESULTADOS: Foram encontradas várias categorias nas dimensões macroambiente, microambiente e individual dos determinantes da atividade física no trabalho dos diferentes sectores; o sector da saúde não foi habitualmente considerado como devendo proporcionar administração para a ação intersectorial neste domínio; foram identificados os critérios: com menor expressão no material analisado, aos quais é atribuída maior importância e aqueles com menor aplicabilidade nos documentos analisados. CONCLUSÕES: Não podemos afirmar que exista uma abordagem política/estratégica integrada de abrangência nacional, operacional, no que respeita à promoção da atividade física para a saúde. São limitadas as conclusões pelas características inerentes ao tipo de estudo desenhado, no entanto, pensamos ter contribuído para descrever as principais políticas e estratégias de ação intersectorial na promoção de HEPA em Portugal. Estudos mais abrangentes em termos de níveis de governação, sectores envolvidos e período temporal deverão ser desenvolvidos de forma a potenciar o desenvolvimento da atividade física e saúde pública.

Socio-demographic correlates of physical activity of European adults: A cross-sectional study from the European Social Survey

ABSTRACT - Background: From a public health perspective, the study of socio-demographic factors related to physical activity is important in order to identify subgroups for intervention programs. Purpose: This study also aimed to identify the prevalence and the socio-demographic correlates related with the achievement of recommended physical activity levels. Methods: Using data from the European Social Survey round 6, physical activity and socio-demographic characteristics were collected from 39278 European adults (18271 men, 21006 women), aged 18-64 years, from 28 countries in 2012. Meeting physical activity guidelines was assessed using World Health Organization criteria. Results: 64.50% (63.36% men, 66.49% women) attained physical activity recommended levels. The likelihood of attaining physical activity recommendations was higher in age group of 55-64 years (men: OR=1.22, p<0.05; women: OR=1.66, p<0.001), among those who had completed high school (men: OR=1.28, p<0.01; women: OR=1.26, p<0.05), among those who lived in rural areas (men: OR=1.20, p<0.001; women: OR=1.10, p<0.05), and among those who had 3 or more people living at home (men: OR=1.40, p<0.001; women: OR=1.43, p<0.001). On the other hand, attaining physical activity recommendations was negatively associated with being unemployed (men: OR=0.70, p<0.001; women: OR=0.87, p<0.05), being a student (men: OR=0.56, p<0.001; women: OR=0.64, p<0.01), being a retired person (men: OR=0.86, p<0.05) and with having a higher household income (OR=0.80, p<0.001; women: OR=0.81, p<0.01). Conclusion: This research helped clarify that, as the promotion of physical activity is critical to sustain health and prevent disease, socio-demographic factors are important to consider when planning the increase of physical activity.

New measurements of energy expenditure and physical activity in chronic kidney disease.

The accurate estimation of total daily energy expenditure (TEE) in chronic kidney patients is essential to allow the provision of nutritional requirements; however, it remains a challenge to collect actual physical activity and resting energy expenditure in maintenance dialysis patients. The direct measurement of TEE by direct calorimetry or doubly labeled water cannot be used easily so that, in clinical practice, TEE is usually estimated from resting energy expenditure and physical activity. Prediction equations may also be used to estimate resting energy expenditure; however, their use has been poorly documented in dialysis patients. Recently, a new system called SenseWear Armband (BodyMedia, Pittsburgh, PA) was developed to assess TEE, but so far no data have been published in chronic kidney disease patients. The aim of this review is to describe new measurements of energy expenditure and physical activity in chronic kidney disease patients.

Opinions and attitudes of a sample of Swiss physicians about physical activity promotion in a primary care setting

Little is known about the opinions, beliefs and behavior of Swiss physicians regarding physical activity (PA) promotion in a primary care setting. A qualitative study was performed with semi-structured interviews. We purposively recruited and interviewed 16 physicians in the French speaking part of Switzerland. Their statements and ideas regarding the promotion of PA in a primary care setting were transcribed and synthesized from the tape recorded interviews. Les opinions, les représentations et les comportements des médecins suisses en matière de promotion de l'activité physique au cabinet médical restent largement méconnus en Suisse. Une étude qualitative a été réalisée au moyen d'entretiens semi-structurés. Nous avons intentionnellement recruté et interviewé 16 médecins en Suisse romande. Leurs opinions et attitudes concernant la promotion de l'activité physique au cabinet médical ont été transcrites et synthétisées à partir de l'enregistrement de ces entretiens.

Physical activity attenuates the influence of FTO variants on obesity risk: a meta-analysis of 218,166 adults and 19,268 children.

BACKGROUND: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). METHODS AND FINDINGS: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r(2)>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (p(interaction)  = 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio  = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio  = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. CONCLUSIONS: The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity.

Effectiveness of three different walking prescription durations on total physical activity in normal- and overweight women.

OBJECTIVE: While there is a dose-response relationship between physical activity (PA) and health benefit, little is known about the effectiveness of different PA prescriptions on total daily PA. AIM: To test, under real-life conditions and using an objective, non-invasive measurement technique (accelerometry), the effect of prescribing additional physical activity (walking only) of different durations (30, 60 and 90 min/day) on compliance (to the activity prescribed) and compensation (to total daily PA). Participants in each group were prescribed 5 sessions of walking per week over 4 weeks. METHODS: 55 normal-weight and overweight women (mean BMI 25 ± 5 kg/m(2), height 165 ± 1 cm, weight 68 ± 2 kg and mean age 27 ± 1 years) were randomly assigned to 3 prescription groups: 30, 60 or 90 min/day PA. RESULTS: Walking duration resulted in an almost linear increase in the number of steps per day during the prescription period from an average of about 10,000 steps per day for the 30-min prescription to about 14,000 for the 90-min prescription. Compliance was excellent for the 30-min prescription but decreased significantly with 60-min and 90-min prescriptions. In parallel, degree of compensation subsequent to exercise increased progressively as length of prescription increased. CONCLUSION: A 30-min prescription of extra walking 5 times per week was well tolerated. However, in order to increase total PA further, much more than 60 min of walking may need to be prescribed in the majority of individuals. While total exercise 'volume' increased with prescriptions longer than 30 min, compliance to the prescription decreased and greater compensation was evident. © 2014 S. Karger GmbH, Freiburg.

Socio-cultural determinants of adiposity and physical activity in preschool children: a cross-sectional study.

Both individual socio-cultural determinants such as selected parental characteristics (migrant background, low educational level and workload) as well as the regional environment are related to childhood overweight and physical activity (PA). The purpose of the study was to compare the impact of distinct socio-cultural determinants such as the regional environment and selected parental characteristics on adiposity, PA and motor skills in preschool children. Forty preschools (N = 542 children) of two culturally different urban regions (German and French speaking part of Switzerland) participated in the study (Ballabeina Study). Outcome measures included adiposity (BMI and skinfold thickness), objectively measured sedentary activities and PA (accelerometers) and agility performance (obstacle course). Parental characteristics (migrant status, educational level and workload) were assessed by questionnaire. Children from the French speaking areas had higher adiposity, lower levels of total and of more intense PA, were more sedentary and less agile than children from the German speaking regions (percent differences for all outcome parameters except for BMI ≥10%; all p ≤ 0.04). Differences in skinfold thickness, sedentary activities and agility, but not in PA, were also found between children of Swiss and migrant parents, though they were ≤8% (p ≤ 0.02). While paternal workload had no effect, maternal workload and parental education resulted in differences in some PA measures and/or agility performance (percent differences in both: ≤9%, p ≤ 0.008), but not in adiposity or sedentary activities (p = NS). Regional differences in skinfold thickness, PA, sedentary activities and agility performance persisted after adjustment for parental socio-cultural characteristics, parental BMI and, where applicable, children's skinfolds (all p ≤ 0.01). The regional environment, especially the broader social environment, plays a prominent role in determining adiposity, PA and motor skills of young children and should be implicated in the prevention of obesity and promotion of PA in children. clinicaltrials.gov NCT00674544.

Exploring the experiences of youth in a development program with integrated physical activity in Costa Rica

National governments, the United Nations, and other organizations have deemed sport and other means of physical activity such as recreation, games and play for development a useful means for addressing a wide range of problems in communities and more specifically, providing youth with an opportunity to experience the benefits of physical activity. There is a need for research that furthers our understanding of how participants experience these programs. Specifically, the purpose of this study, was to better understand the lived experiences of the participants in a YMCA camp program that integrated physical activity and play for the specific development of poor youth street workers. A phenomenological approach infonned by a critical perspective (Creswell, 2003; Rossman & Rallis, 2003) was used. The study took place through the Asociaci6n Cristiana de J6venes de Costa Rica (ACJ) in Central America. The focus was on a camp program and the lived experiences of six purposefully chosen, youth street workers between the ages of 13-17. Their experiences were explored through semi-structured interviews. Other data that fonn the study include: field notes, observations, a reflexive journal and document analysis. The findings that emerged from the data include main themes of relationships, poverty, personal change and empowennent. For many youth, the ACJ is a relatively safe place to play, to "detach," their minds, to "distract" and "disorient" themselves from their dysfunctional families, violent neighbourhood, the poverty they live in, and from the necessity of having to work in the street to supplement the family income. Although many studies have shown that programs that include physical activity, play and/or sport have a positive impact on youth with regard to healthy development and improvements in well-being, there has been little work done to address the voices and experiences of the youth that participate in these programs. Using an interpretive-critical approach, this study focused on the participants' personal backgrounds, their experiences within the program and their critical reflections on the program. This study draws from a phenomenological philosophy and method to report findings from participants in an ACJ program in Costa Rica. This research shows how these youth were given the opportunity to use the program and the ACJ property as a relatively safe place to play, to behave like the youth they are, to establish and maintain their friendship networks, and develop empathy and conflict resolution skills. The fmdings from this study reveal how by participating in the ACJ program they each described a personal change, wherein they felt empowered to learn they could positivel y control themselves and as a result positively affect their own futures. These fmdings contribute knowledge surrounding the lived experiences of youth in developmental programs that use physical activity.

A physical activity intervention in a workplace setting

Physical inactivity poses a huge burden on Canada's health care system and is detrimental to the health of Canadians (Katzmarzyk & Janssen, 2004). Walking is a viable option for individuals to become physically active on a daily basis and is in fact the most commonly reported leisure time physical activity. It has been associated with many health benefits including weight loss/weight control, reduced risk of coronary artery disease and diabetes, lowered blood pressure, and improved psychological wellbeing (Brisson & Tudor-Locke, 2004). Specifically, individuals' stage of change, selfefficacy and health related quality of life (HRQL) are three psychological constructs that can be greatly improved with increased physical activity (Dishman, 1991; Penedo & Dahn, 2005; Poag & McAuley, 1992). Public health physical activity recommendations exist but many individuals find these difficult to meet due to overly busy lifestyles (Public Health Agency of Canada, 2003). Pedometers are inexpensive devices that can monitor individual bouts of walking so that the incorporation of physical activity into one's daily life is more plausible. They are also excellent tools for motivation, goalsetting, and immediate feedback (Brisson & Tudor-Locke, 2004). Since many people spend a large proportion of their time at their places of employment, workplaces have begun to be a common site for the development of physical activity interventions. These programs have been growing in popUlarity and have shown numerous benefits for both employees and employers (Voit, 2001). The purpose of the current study was to implement and evaluate the use of a pedometer-based physical activity intervention incorporating goal-setting and physical activity logs in a workplace setting, and to examine the relationship between different types of self-efficacy (task, barrier, and scheduling) and different phases of the intervention. Twenty male participants from a local steel manufacturing plant who exhibited health risk factors (e.g. hypertension, diabetes, etc.) were assigned to one of two groups (group A or group B). All participants were asked to wear pedometers on their waists, record their daily steps, set goals that were outlined on a step-tracking sheet (detennined by their baseline number of steps), and keep track of their work days, wakelbed time, sedentary time, and time spent doing other physical activity. Group A began the intervention immediately following the baseline measures, whereas group B continued with their regular routine for 4 weeks before beginning. Physiological measures (height, weight, blood pressure, relative body fat, waist and hip circumference, and body mass index) were taken and a battery of questionnaires that assessed barrier, task and scheduling self-efficacy, HRQL, and stage of change administered at baseline, week 5 (end of intervention for group A), week 9 (end of intervention for group B; follow-up for group A) and week 13 (follow-up for both groups). Results showed that this workplace physical activity intervention was successful at increasing the participants' daily steps, that task self-efficacy is a significant predictor of participants' exercise adherence during the initial stages of participation (intervention phase), and that the participants felt that this intervention was effective. Finally, further exploratory analyses showed that this intervention was effective for all participants, but most valuable for participants most in need of improvement - that is, those who were most sedentary prior to the intervention. This intervention is an inexpensive use of simple and effective tools (e.g. pedometers), has the potential to attract a wide variety of participants and become a pennanent part of any health promotion initiative.

Relationship between physical activity and resting secretory immunity in children

This study examined relationships among physical activity, body fat and salivary immonoglobulin A (sIgA) levels in adolescent children of Southern Ontario. Gender differences on these factors were also assessed. Sixty-one grade-five students (10-1 lyrs), males (n=29) and females (n=31), who had not received a flu vaccination in the past 12 months, participated in the study. They were assessed for: aerobic power (20-m shuttle run), relative body fat (bioelectrical impedance analysis), sIgA, sIgA/albumin ratio, and salivary Cortisol. Each subject completed the Habitual Activity Estimation Scale and the Participation Questioimaire. Students wore a pedometer for 48h to estimate their average total distance traveled per day. The results show 40% of the children were over 25% body fat and 50% of them spend less than five hours per day in any physical activities. Salivary IgA was not related to salivary Cortisol, physical activity, fitness level or body fat in this age group. There were no gender differences in sIgA and Cortisol levels. Boys had a significantly higher aerobic power and daily distance traveled, but reported similar organized and fi-ee time activity participation levels as the girls. The test-retest reproducibility for salivary Cortisol was 0.663 (p<0.01), while long term sIgA and sIgA/albumin ratio reproducibility was non-significant for repeated measurements taken after six weeks. It was found that salivary IgA has not been shovm to be a stable measure in children, in contrast to the results found in the literatiu-e that tested adults and the relationship with physical activity, fitness level and body fat.