The Effect of Exercise Training Intensity on VO2max in Healthy Adults:An Overview of Systematic Reviews and Meta-Analyses

Abstract

This study aimed to evaluate system atic review sand meta-analysesthathaveexaminedtheeffectofexercisetrainingonVO2max in healthy individuals at different intensities. Five databases were searched: EBSCOhost, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Google Scholar. Eligibility criteria for selecting reviews included systematic reviews and meta-analyses of healthy adultsthatexaminedtheeffectoflowerintensitytraining(LIT)and/orhighintensitytraining(HIT)onVO2max.Elevenreviews met the eligibility criteria. All reviews were of moderate-to-very strong methodological quality.The included reviews reported data from179primarystudieswithanaverageof23±10studiesperreview.Allreviewsincludedinthisoverviewshowedthatexercise training robustly increased VO2max at all intensities. Three meta-analyses that compared LITversus HITprotocols on VO2max reported small/moderate beneficial effects for HIT over LIT; however, the beneficial effects of HIT on VO2max appear to be moderated by training variables other than intensity (e.g., training impulse, interval length, training volume, and duration) and participants’ baseline characteristics (e.g., age and fitness levels). Overall, evidence from this overview suggests that the apparent differences between LITand HITprotocols on VO2max were either small, trivial, or inconclusive, with several methodological considerations required to standardise research designs and draw definitive conclusions.