Environmental modifications to increase physical activity during recess: preliminary findings from ready for recess.

The purpose of this study was to determine the effectiveness of Ready for Recess: an elementary school recess intervention targeting staff training (ST) and providing recreational equipment (EQ). Ready for Recess had 4 intervention schools: 1) EQ+ST, 2) EQ, 3) ST, and 4) control. Moderate-to-vigorous physical activity (MVPA) was assessed with accelerometers at the four schools in 257 3rd- to 6th-grade children. Random intercept models for overweight/obese (OWOB) and healthy weight (HW) for boys and girls separately, examined change in percentage of time spent in MVPA during recess across EQ+ST, EQ, and ST compared with the control from baseline to postintervention. HW boys receiving EQ+ST increased MVPA by 19.4%, OWOB boys receiving ST increased MVPA by 4.5%, OWOB girls receiving EQ-ST increased MVPA by 6.0%, while HW girls receiving EQ decreased MVPA by 13.6% in comparison with the control. Ready for Recess represents a possible means to increase MVPA in OWOB girls/boys, populations least likely to meet MVPA recommendations. However, the effect of the intervention was not uniform across all subgroups.