la diversion. Para ello, se desarrollo un estudio cuasiexperimental en el que participaron 54 alumnos (M = 16.4; DT = 1.51), de genero masculino (n = 32) y de genero femenino (n = 22) de cinco centros de ensenanza secundaria de la comunidad autonoma de Extremadura. Los sujetos del grupo experimental (n = 27) desarrollaron un programa de intervencion de entrenamiento autonomo de tipo aerobico registrado y controlado en la aplicacion movil Endomondo Sport Tracker de ocho semanas de duracion. Los componentes del grupo de control experimental (n = 27) registraron el mismo programa de entrenamiento autonomo en una ficha de registro facilitada por el grupo investigador. Los resultados demostraron que la satisfaccion de la necesidad de competencia, la autodeterminacion hacia la realizacion de la actividad y la diversion al realizarla fueron mayores en aquellos participantes que utilizaron la aplicacion respecto a aquellos que no la utilizaron. A pesar de ello, no se registraron diferencias significativas en la mayoria de lasvariables analizadas en el estudio, por lo que se considera necesario seguir indagando en esta linea de trabajo.Follow-up in healthy schoolchildren and in adolescents with DOWN syndrome: psycho-environmental and genetic determinants of physical activity and its impact on fitness, cardiovascular diseases, inflammatory biomarkers and mental health; the UP&DOWN StudyCastro-Pinero J, Carbonell-Baeza A, Martinez-Gomez D, Gomez-Martinez S, Cabanas-Sanchez V, Santiago C, et al 2014Background: An objective diagnosis of sedentary behaviour as well as of the physical activity and fitness levels in youth and to better understand how lifestyle is associated with cardiovascular disease risk factors and other phenotypes is of clinical and public health interest, and might be informative for developing intervention studies focused on the promotion of physical activity in these population. The aim of this methodological paper is to describe the design and assessment in the UP&DOWN study. Methods/Design: The UP&DOWN study is a multi-center follow-up design where 2225 Spanish primary and secondary schoolchildren from Cadiz and Madrid, respectively, as well as 110 Spanish adolescents with Down syndrome from Madrid and Toledo were recruited to be assessed. Nine main measurement categories are assessed: i) socio-demographic and early determinants; ii) environmental determinants; iii) physical activity and sedentary behaviour; iv) health-related fitness; v) blood pressure and resting heart rate; vi) mental health; vii) dietary patterns; viii) blood samples; and ix) genetic analysis. During the 3-yr follow-up study, socio-demographic and early determinants, and genetic analysis are only assessed in the first year. Blood sampling is assessed in the first year and the third year (2nd follow-up), and all the other measurements are assessed every year. Discussion: The findings of the UP&DOWN study may help the Health Information Systems and policy makers to identify the target population for primary prevention and health promotion policies, and to develop and test preventive strategies. Moreover, these data will allow following the trends at population level, as well as to modify/adapt/create new evidence-based physical activity guidelines at national level. The findings will also serve as a scientific platform for interventional studies.Differences in Overweight and Obesity among Children from Migrant and Native Origin: The Role of Physical Activity, Dietary Intake,