Objective:
     
     To evaluate the completeness of exercise prescription in randomised controlled trials (RCTs) for patellofemoral pain (PFP), identify which elements are most frequently missing and supplement recommendations based on additional data from authors.
   

Design:
     
     Systematic review.
   

Data sources:
     
     All studies included in the most recent Cochrane review were evaluated. Additionally, the Cochrane search was updated in June 2016 in Cochrane, MEDLINE, EMBASE, PEDro, CINAHL and AMED databases. Two raters independently assessed completeness of reporting using the Toigo and Boutellier mechanobiological exercise descriptors, and Template for Intervention Description and Replication (TIDieR) checklist. Authors were also contacted to provide additional information.
   

Eligibility criteria for selecting studies:
     
     RCTs of exercise interventions for PFP.
   

Results:
     
     We included 38 RCTs. The level of exercise prescription detail was low, with no study providing complete information. The most commonly reported exercise descriptors were the 'duration of the experimental period' (n=38/38) and 'number of exercise interventions' (n=35). From TIDieR, the most commonly reported items were the 'intervention name' (n=38) and 'rationale' (n=36).The least reported items from the exercise descriptors were 'volitional muscular failure', 'temporal distribution of contraction modes', 'time under tension' and 'recovery between exercise sessions' (all n=2/38). From TIDieR, the least reported item was 'How well (fidelity and adherence)' (n=3/38).36 authors were contacted, with 22 replies and 13 providing additional exercise prescription details .
   

Conclusion:
     
     Exercise prescriptions in RCTs with proven efficacy for PFP are poorly reported, impairing their implementation in clinical practice.
   

Prospero registration number:
     
     CRD42016039138.