Physical exercise, detraining and lipid profile in obese children: a systematic review.

INTRODUCTION Detraining is the loss of improvements obtained through the participation in physical exercise/training after training cessation, an aspect that has been poorly studied in obese child population. Therefore, the purpose of this study was to assess the effects of detraining on the lipid profile (HDL, LDL, total cholesterol and triglycerides) of obese children. POPULATION AND METHODS Studies were collected through a search across seven databases. The search was limited to physical exercise programs that lasted, at least, eight weeks and the corresponding detraining, with an assessment of obese children lipid profile. Effect size (ES), 95% confidence intervals and study heterogeneity were estimated using Cochran's Q test (random effects model). RESULTS Five studies complied with the inclusion criteria and were selected for review (n= 330). In general, intra-group results (posttest versus detraining) indicated that, following detraining, blood levels of HDL cholesterol (ES= 0.12) and total cholesterol (ES= 1.41) were increased. Likewise, inter-group results (experimental group versus control group) confirmed the increase of HDL cholesterol following detraining (ES= 0.49). CONCLUSIONS The results of this systematic review suggest that detraining after a physical exercise program does not lead to a significant loss of the benefits gained in relation to the lipid profile of obese children. However, given the number of analyzed studies and the heterogeneity observed in the analyses and the period defined as detraining (12 to 48 weeks), a higher number of well designed studies is required to obtain more conclusive results.