journal of health psychology
exercise-based interventions: QH(2)=12.12.p=.002.
The type of control group (i.e. no treatment or placebo control) did not moderate the size of the effect: QH(1)=2.89,p=.08. No difference in the size of the effect was evidenced for those who improved on either fitness or body composition from pre-to post-intervention compared to those who did not improve on fitness (QB(1)=0.001,p=.97) or body composition (QB(1)=0.12,p=.73)
from pre-to post-intervention.
Finally, no significant ES difference was evidenced for published versus unpublished reserch: QB(1)=0.25,p=.61.
Most of the studies