Exercise adaptations are highly dependent on the specific training stimulus (Nader, 2006; Egan and Zierath, 2013; Hughes et al., 2018). Therefore, an apt description of physical training programs is essential for adequate planning of neuromuscular, cardiovascular, metabolic, and functional exercise performance and recovery enhancements. Although muscle strength, power, flexibility, and endurance training are well-defined concepts within exercise prescription and muscle performance, functional training (FT) does not have a universal definition. Examining the manuscript of La Scala Teixeira et al. (2017), reviled inconsistent concepts regarding the definition of FT. Specifically, they did not differentiate FT from strength, power, flexibility, or endurance training programs. In the PubMed database, their manuscript (La Scala Teixeira et al., 2017) was cited by six articles (Crawford et al., 2018; Da Silva-Grigoletto et al., 2019, 2020; Drum et al., 2019; La Scala Teixeira et al., 2019; Muyor et al., 2020), three of which were self-citations. Despite not yet (as of May 2021) being extensively cited in the literature, their manuscript (La Scala Teixeira et al., 2017) has a total of 9,535 views (https://www.frontiersin.org/articles/10.3389/fphys.2017.00643/full) and 1,282 downloads (http://loop-impact.frontiersin.org/impact/article/285700#totalviews/downloads), and may create a relevant social and health impact. Considering that functional fitness training was regarded as one of the Top 20 Worldwide Fitness Trends for 2021 (Thompson, 2021), the dissemination of inconsistent concepts regarding the definition of FT may create substantial confusion among students, coaches, athletes, and sports scientists. In this context, this commentary builds upon the concepts and characteristics of FT presented by La Scala Teixeira et al. (2017). Therefore, we aimed to present a critical commentary to enrich the debate of such a topic and alleviate the potential confusion.