Injuries During High-Intensity Functional Training: Systematic Review and Meta-Analysis.

High-intensity functional training (HIFT) involves high-volume and high-intensity physical activities with short rest periods between movements and use of multiple joint exercises. This article reports the results of a systematic review and meta- analysis of studies involving injuries during HIFT. Individual studies were selected for review if they involved individuals =18 years of age and provided quantitative data on injury prevalence and/or injury rates during HIFT. Twenty-eight studies involving 11,089 participants met the inclusion criteria. There was considerable variability in individual studies with injury prevalences ranging from 12% to 74% and injury rates from 0.04 to 18.90 injuries/1000 h of training. Meta-analyses indicated that the overall injury prevalence was 36% (95% confidence interval [95% CI] = 32-41%) and overall injury rate 4.3 injuries/1000 h (95% CI = 3.35-5.23). Injury rates among the five available prospective cohort studies was considerably higher, 9.9 injuries/1000 h (95% CI = 3.3-16.4). The most commonly injured anatomical locations (with % of total injuries) were the shoulder (26%), back/spine (26%), knee (14%), wrist/hands/fingers (12%), arm/elbow (10%), and ankle/foot (6%). Given the higher injury rates among prospective studies that likely more effectively tracked injuries over time, more prospectively designed studies are required before the injury rate during HIFT can be appropriately quantified.