Effects of high-intensity functional training on physical fitness in healthy individuals: a systematic review with meta-analysis.

The purpose of this study was to conduct a meta-analysis of the effects of high-intensity functional training on the physical fitness of healthy individuals. This system review followed the PRISMA guidelines and has been registered in PROSPERO with the registration number CRD42023475055. As of January 2024, we did a thorough search across five databases: PubMed, Scopus, Web of Science, EBSCOhost, and Cochrane Library. We evaluated the methodological quality of the included study by TEST EX tool and ROB 2 tool. GRADE framework determines the level of certainty of evidence. Meta-analysis of random effects model calculations. 19 high-quality studies were included in this review, involving 911 healthy individuals. Positive effects were observed in improving strength (ES = 1.380; p < 0.001), power (ES = 1.320; p < 0.001), speed (ES = 3.093; p < 0.001), endurance (ES = 1.802; p < 0.001), and agility (ES = 2.086; p < 0.001). However, flexibility performance had no significant effect (ES = 0.640; p = 0.092), which may be attributed to limited articles. Therefore, it is necessary to expand high-quality research to explore the impact of HIFT on the physical fitness in healthy individuals.