ObjectiveTo compare the effects of moderate intensity continuous training (MICT) and high intensity interval training (HIIT) on adult lipid profiles; to identify training or participant characteristics that may determine exercise-induced change in total cholesterol (TC), triglycerides (TRG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C).DesignSystematic review and meta-analysis.Data sourcesEnglish language searches of several databases were conducted from inception until September 2019.Eligibility criteria for excluding studiesInclusion: (1) published randomised controlled human trials with group population n≥5; (2) intervention duration ≥4 weeks; (3) comparing HIIT with MICT; and (4) reporting pre–post intervention lipid measurements. Exclusion: subjects with chronic disease, <18 years, pregnant/lactating, in elite athletic training; and studies with a dietary or pharmaceutical intervention component.ResultsTwenty-nine data sets (mmol/L) of 823 participants were pooled and analysed. Neither HIIT nor MICT was better in decreasing TC (0.10 (−0.06 to 0.19), p=0.12, I2=0%), TRG (−0.05 (−0.11 to 0.01), p=0.10, I2=0%), LDL-C (0.05 (−0.06 to 0.17), p=0.37, I2=0%), or TC/HDL-C (−0.03 (−0.36 to 0.29), p=0.85, I2=0%). HIIT significantly raised HDL-C (0.07 (0.04 to 0.11), p<0.0001, I2=0%) compared with MICT.ConclusionNeither HIIT nor MICT is superior for altering TC, TRG, or LDL-C, or TC-HDL-C ratio. Compared with MICT, HIIT appeared to significantly improve HDL-C. Clinicians may prescribe either protocol to encourage participation in exercise and reduce cardiovascular risk. To raise HDL-C, HIIT may result in a larger effect size compared with MICT.PROSPERO registration numberCRD42019136722.

ObjectivesTo estimate the change in the standard lipid profile (SLP) of adults diagnosed with ≥3 metabolic syndrome (MetS) factors following aerobic exercise training (AET); and to investigate whether study/intervention covariates are associated with this change.DesignSystematic review with univariate meta-analysis and meta-regression.Data sourcesEnglish language searches of online databases from inception until July 2020.Eligibility criteria(1) Published randomised controlled human trials with study population ≥10 per group; (2) sedentary adults with ≥3 MetS factors but otherwise free of chronic disease, not pregnant/lactating; (3) AET-only intervention with duration ≥12 weeks; and (4) reporting pre–post intervention SLP outcomes.ResultsVarious univariate meta-analyses pooled 48 data sets of 2990 participants. Aerobic exercise training significantly (P<.001) improved all lipids (mmol/L mean difference ranges, 95% CIs): total cholesterol, –0.19 (–0.26 to –0.12) to –0.29 (−0.36 to –0.21); triglycerides, −0.17 (–0.19 to –0.14) to –0.18 (−0.24 to –0.13); high-density lipoprotein-cholesterol (HDL-C), 0.05 (0.03 to 0.07) to 0.10 (0.05 to 0.15); and low-density lipoprotein-cholesterol (LDL-C), –0.12 (–0.16 to –0.9) to –0.20 (−0.25 to –0.14). Meta-regression showed that intensity may explain change in triglycerides and volume may explain change in HDL-C and LDL-C.ConclusionAerobic exercise training positively changes the SLP of sedentary and otherwise healthy adults with ≥3 MetS factors. Adjusting AET intervention training variables may increase the effects of AET on triglycerides and HDL-C.PROSPERO registration numberCRD42020151925.

Background Aerobic exercise training (AET) prescribed as lipid management treatment positively affects the standard lipid profile and reduces cardiovascular disease (CVD) risk. Apolipoproteins, lipid and apolipoprotein ratios, and lipoprotein sub-fractions may more effectively predict CVD risk than the standard lipid profile but an AET response in these biomarkers has not been established. Objectives We conducted a quantitative systematic review of randomised controlled trials (RCTs) to (1) determine the effects of AET on lipoprotein sub-fractions, apolipoproteins and relevant ratios; and (2) identify study or intervention covariates associated with change in these biomarkers. Methods We searched PubMed, EMBASE, all Web of Science and EBSCO health and medical online databases from inception to 31 December 2021. We included published RCTs of adult humans with ≥ 10 per group of participants; an AET intervention duration ≥ 12 weeks of at least moderate intensity (> 40% maximum oxygen consumption); and reporting pre/post measurements. Non-sedentary subjects, or those with chronic disease other than Metabolic Syndrome factors, or pregnant/lactating, as well as trials testing diet/medications, or resistance/isometric/unconventional training interventions, were excluded. Results Fifty-seven RCTs totalling 3194 participants were analysed. Multivariate meta-analysis showed AET significantly raised antiatherogenic apolipoproteins and lipoprotein sub-fractions (mmol/L mean difference (MD) 0.047 (95% confidence interval (CI) 0.011, 0.082), P = .01); lowered atherogenic apoliproteins and lipoprotein sub-fractions (mmol/L MD − 0.08 (95% CI − 0.161, 0.0003), P = .05); and improved atherogenic lipid ratios (MD − 0.201 (95% CI − 0.291, − 0.111), P < .0001). Multivariate meta-regression showed intervention variables contributed to change in lipid, sub-fraction, and apoliprotein ratios. Conclusion Aerobic exercise training positively impacts atherogenic lipid and apolipoprotein ratios, alipoproteins, and lipoprotein sub-fractions; and antiatherogenic apolipoproteins and lipoprotein sub-fractions. Cardiovascular disease risk predicted by these biomarkers may be lowered when AET is prescribed as treatment or prevention. PROSPERO ID CRD42020151925.