Inclusion criteria for systematic reviews: 1. All steps of the reviewing processes such as search strategy and inclusion/exclusion criteria are explicitly and clearly defined. 2. The primary studies of the systematic review are exercise interventional studies. In addition to systematic reviews, guidelines and position stands related to resistance exercise training will also be included.
Search strategies and information sources
Two categories of data will be extracted: data from (1) systematic reviews/meta-analyses that investigated the effects of different resistance exercise parameters such as the types of resistance exercise and training frequency, and from (2) position stands or guidelines related to resistance exercise.
Systematic reviews/meta-analyses, guidelines, and position stands will be searched in PubMed and Scopus using the following keywords:
“resistance exercise*” or “resistance train*” or “weight exercise*” or “weight train*” or “weight bear*” or “weight-bear*” “weightlift” or “weight lift*” or “strength train*” or “strength exercise*” or “power train*” or “power exercise” or “explosive exercise*” (in Title/Abstract)
systematic* or meta* or statement* or guideline* or stand* (in Title)
The search syntax is outlined below.
[TITLE-ABS (“resistance exercise*” OR “resistance train*” OR “weight exercise*” OR “weight train*” OR “weight bear*” OR “weight-bear*” OR “weightlift*” OR “weight lift*” OR “strength train*” OR “strength exercise*” OR “power train*” OR “power exercise” OR “explosive exercise*”) AND TITLE (systematic* OR meta* OR statement* OR guideline* OR “position stand*” or recommend*)]
(“resistance exercise*” [Title/Abstract] OR “resistance train*” [Title/Abstract] OR “weight exercise*” [Title/Abstract] OR “weight train*” [Title/Abstract] OR “weight bear*” [Title/Abstract] OR “weight-bear*” [Title/Abstract] OR “weightlift*” [Title/Abstract] OR “weight lift*” [Title/Abstract] OR “strength train*” [Title/Abstract] OR “strength exercise*” [Title/Abstract] OR “power train*” [Title/Abstract] OR “power exercise” [Title/Abstract] OR “explosive exercise*” [Title/Abstract]) AND (systematic* [Title] OR meta* [Title] OR statement* [Title] OR guideline* [Title] OR “position stand*” [Title] or recommend* [Title])
Date: no limitation
Review selection process
The authors TYL and TYC will independently screen the titles and abstracts yielded by the search against the selection criteria. The authors will conduct full-text screenings if the titles and abstracts appear to meet the criteria or there is any uncertainty. Any inconsistency between the two authors will be discussed; if the disagreement cannot be resolved, we will consult the author TMH.
Data extraction and management
Relevant titles and abstracts identified from PubMed and Scopus will be loaded into Microsoft Excel to remove duplicates and then be screened. The reference lists of articles whose full texts are screened will be uploaded to Endnote software.
Basic data including identifier and publication year, PICO, dates covered by the literature search, number of included primary studies and participants, as well as the overall pooled effect estimate with 95% confidence interval for the primary outcome, will be extracted by TYL and TYC independently .
Guidelines and position stands
Identifier, publication year, and the name of the organization that published the guideline or the position stand will be extracted by the same two authors independently.
Quality, overlap, and discordance of included reviews
The quality of reviews will not be judged and issues regarding overlap and discordance will not be resolved because these are beyond the scope of the proposed umbrella review. These issues shall be discussed in other umbrella reviews or tertiary studies.
Items such as training parameters from systematic reviews, guidelines, and position stands, which could potentially influence training efficiency, physiological/psychological functions, other health-related variables, and replication, will be extracted by TYL. For example, if a systematic review reports that training frequency significantly influenced the participants’ health outcomes such as quality of life, then the parameter training frequency will be extracted from this review. In addition, items from CERT, a previously published reporting template for exercise interventional studies, will be adapted if applicable.
There will be two categories of extracted data:
(1) Summary of findings and items extracted from the included systematic reviews/meta-analyses.
(2) Summary of items extracted from the included position stands and guidelines.
We will provide information collected from the included studies in text and table formats. Items from both categories will be combined with those adapted from CERT to build a reporting checklist for resistance exercise studies.
The introduction and method of this protocol are developed according to the reporting checklist for umbrella reviews published by Onishi and Furukawa in 2016 , which was developed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)  and A Measurement Tool to Assess Systematic Reviews (AMSTAR) . Preferred Reporting Items for Overviews of Reviews (PRIOR) was under development when this protocol was constructed . If PRIOR is completed and becomes available while we prepare the manuscript resulting from the proposed study, we will consider using this newer reporting guideline. Otherwise, the checklist and recommendations by Onishi and Furukawa  will be continued to use.