A systematic review using a multi-layered criteria framework for assessing the validity and reliability of velocity monitoring devices in resistance training.

Background: Velocity-Based Training (VBT) is an emerging method in resistance training for objectively prescribing and monitoring training intensity and neuromuscular function. Given its growing popularity, assessing the validity and reliability of VBT devices is critical for strength and conditioning coaches.

Objective: The primary purpose of this review was twofold: (1) to identify and address methodological gaps in current assessments of VBT device validity and reliability, and (2) to propose and apply a novel, multi-layered, criterion-based framework-developed in collaboration with statisticians and domain experts-for evaluating these devices.

Methods: A systematic search was conducted in PubMed, Scopus, and SPORTDiscus following PRISMA guidelines, focusing on original research studies published before February 2024 that assessed VBT device validity or reliability. Out of 568 studies identified, 75 met the inclusion criteria.

Results: Among the included studies, 66 investigated device validity and 56 examined reliability, with some studies addressing both aspects. Notably, only 5 of the 66 validity studies met all of the proposed criteria, while just 16 of the 56 reliability investigations satisfied the required statistical thresholds defined by our framework. These findings highlight significant methodological variability and underscore the need for more standardized evaluation practices.

Conclusions: This review systematically evaluated the validity and reliability of various VBT devices and introduced a robust, multi-layered framework for their assessment. By integrating statistician-led and domain expert-led criteria, the framework offers a standardized approach that enhances the precision of device evaluation. Promising tools identified include the GymAware LPT, Perch Motion Capture Single Camera System, Flex optical device, and VmaxPro. Future research should build upon and refine this methodology to further standardize study designs, improve data reporting, and ultimately support more informed decision-making in sports technology and training practice.