title: [Improving physical fitness in adolescents through a school-based intervention: the EDUFIT study].
abstract: OBJECTIVE
  Physical fitness level is a marker of cardiovascular health in young people. The aim of this study was to analyze the effects of a school-based intervention program, focused on increasing the volume and intensity of physical education (PE) sessions, on adolescents' physical fitness.
  
  
  METHODS
  Sixty-seven adolescents (12-14 years old) from three secondary school classes participated in a 16-week intervention. The classes were randomly allocated to the control group, experimental group 1 (EG1) or experimental group 2 (EG2). The control group received standard PE (2 sessions/week), the EG1 received 4 standard PE sessions/week and the EG2 received four high-intensity PE sessions/week. Aerobic fitness, muscle strength, speed-agility and flexibility were assessed using previously validated field-based tests before and after the intervention.
  
  
  RESULTS
  Doubling the number of PE sessions/week resulted in improvements in aerobic fitness and flexibility (P=.008 and P=.04, respectively). Further increases in the intensity of the sessions were related to improvements in speed-agility (P<.001). The maximal oxygen consumption increased by 3 and 5 mL/kg/min in the EG1 and EG2, respectively. No differences were observed for muscle strength.
  
  
  CONCLUSIONS
  The results suggest that doubling the frequency of PE sessions is a sufficient stimulus to improve physical fitness, particularly aerobic fitness, which has been shown to be a powerful indicator of cardiovascular health in children and adolescents. Future studies involving larger sample sizes should confirm or refute these findings.
authors: Departamento de Educación Física, IES J. Martínez Ruiz Azorín, Yecla, Murcia, Consejería de Educación, Formación y Empleo, Murcia, España. aniel.navarro@murciaeduca.es
authors: Daniel N
authors: DN
authors: Ardoy
authors: Juan M
authors: JM
authors: Fernández-Rodríguez
authors: Jonatan R
authors: JR
authors: Ruiz
authors: Palma
authors: P
authors: Chillón
authors: Vanesa
authors: V
authors: España-Romero
authors: Manuel J
authors: MJ
authors: Castillo
authors: Francisco B
authors: FB
authors: Ortega