A content analysis of the high-intensity functional training literature: a look at the past and directions for the future

Purpose As a form of high-intensity functional training (HIFT), CrossFit training has grown in popularity over the last decade. The aim of this analysis is to provide researchers with a tool to further guide scientific inquiry in this area of research. Methods Even though systematic reviews and meta-analyses are preferred when analysing and synthesizing large numbers of scientific studies, the current literature on CrossFit training is scarce. Therefore, we used a content analysis approach to (1) review the literature on the topic; (2) synthesize the available research and examine the most popular issues, trends, and methodologies used; and (3) present an overall state of the literature and propose potential directions for future research. Results A total of 104 studies related to HIFT and CrossFit training were identified. These were published between 2007 and 2018 in 15 different countries, in 69 journals. The analysis referred to 6 main themes: (1) publication year, (2) country of research, (3) the peer-review journals publishing this type of research, (4) topical areas primarily studied, (5) research design, and (6) characteristics of individuals involved in this training modality. Conclusions To our knowledge, this is the first study to provide a content analysis of the available literature on HIFT and CrossFit training. The literature contributed significantly to the development of HIFT concepts, yet additional studies are needed to elucidate how HIFT/CrossFit training may differ from more traditional training programs. Hopefully, our study will facilitate collaboration among scholars interested in HIFT modalities.