ObjectiveTo examine the effect of exercise during the first year postpartum on pelvic floor disorders and diastasis recti abdominis.DesignSystematic review with random effects meta-analysis.Data sources: MEDLINE, EMBASE, CINAHL, SPORTDiscuss, Evidence-Based Medicine Reviews (Ovid), Scopus, Web of Science and ClinicalTrials.gov were searched until 12 January 2024.Eligibility criteria for selecting studiesStudies of all designs (except case studies) and languages were included if they contained information on the Population (individuals in the first year postpartum), Intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise alone (‘exercise-only’) or in combination with other intervention (eg, biofeedback; ‘exercise+co-intervention’)), Comparator (no exercise or different exercise measures) and Outcome (symptom severity and risk of urinary incontinence, anal incontinence, pelvic organ prolapse, diastasis recti abdominis and sexual function).Results65 studies (n=21 334 participants) from 24 countries were included. ‘Moderate’ certainty of evidence revealed that pelvic floor muscle training reduced the odds of urinary incontinence by 37% (seven randomised controlled trials (RCTs), n=1930; OR 0.63, 95% CI 0.41 to 0.97, I272%) and pelvic organ prolapse by 56% (one RCT, n=123; OR 0.44, 95% CI 0.21 to 0.91) compared with control groups. ‘Low’ certainty of evidence showed a greater reduction in inter-rectus distance measured at rest and during a head lift following abdominal muscle training compared with no exercise. Evidence on the effect of exercise on the risk of anal incontinence and diastasis recti abdominis, as well as the severity of anal incontinence, urinary incontinence, pelvic organ prolapse and sexual function, is limited.ConclusionEvidence supports the effectiveness of postpartum pelvic floor muscle training in reducing the odds of urinary incontinence and pelvic organ prolapse and postpartum abdominal exercise training in reducing inter-rectus distance.PROSPERO registration numberCRD42022359282.