Effect of a physical education-based fitness intermittent teaching unit on high school students' cardiorespiratory fitness: a cluster-randomized controlled trial.

Abstract

The aim of this study was to compare the effect of the intermittent and traditional physical fitness-based teaching units on cardiorespiratory fitness and physical activity levels in high school students during Physical Education sessions. One hundred and three high school students (Mage=13.6±0.7) from six classes, balanced by grade, were cluster-randomly assigned into traditional (TG), intermittent (IG), and control (CG) groups. The TG performed a fitness teaching unit twice a week for nine weeks (35-40 minutes of the main part of each session). The IG worked during the first half of the sessions' main part (18-20 minutes) similarly to the TG, and during the second half they worked on technical-tactical aspects of invasion sports. Students' cardiorespiratory fitness was measured at the beginning and at the end of the teaching unit. Physical activity levels were measured objectively through a heart rate monitor and subjectively by a self-reported scale during Physical Education sessions. Both traditional and intermittent teaching units developed students' cardiorespiratory fitness levels (Δ post-pre-intervention: TG, M∆=19.8, SE=9.4; IG, M∆=16.6, SE=7.7); P<0.01). Additionally, both TG (M=86.2, SE=9.9) and IG (M=90.9, SE=7.6) had higher physical activity levels than the CG (M=76.3, SE=13.5) (P<0.05). However, no differences in physical activity levels were found between the IG and TG (P>0.05). The intermittent teaching unit allowed the simultaneous development of cardiorespiratory fitness and another curricular objective in the same Physical Education sessions.