The editorial introduces flywheel (isoinertial) resistance training, originally developed for astronaut muscle preservation, and outlines its unique mechanical advantages—rotational inertia providing continuous resistance and the capacity for eccentric overload. It highlights the need for deeper physiological understanding and practical guidance to integrate flywheel training into sport and rehabilitation. The piece presents the Frontiers in Physiology Research Topic comprising seven peer‑reviewed contributions: three original research articles (Martín‑Rivera et al. on load quantification via concentric linear velocity; Weng et al. on accentuated eccentric loading improving running economy and neuromuscular performance; Maroto‑Izquierdo et al. comparing submaximal versus supramaximal eccentric loads on muscle mass, hormones, and strength), two opinion pieces (Beato et al. offering periodization frameworks for team sports; Maroto‑Izquierdo et al. discussing load monitoring and testing methods), and two brief reports (de Keijzer et al. examining inertia‑power relationships and reliability of peak power measures; de Keijzer et al. surveying therapists’ adoption, perceived benefits, and barriers to flywheel training). The editorial synthesizes these findings, emphasizing practical applications, methodological recommendations, and future research directions, and concludes with statements on funding, author contributions, and conflict of interest.
Topics
Origins and Unique Mechanics of Flywheel Training
Explains the development of flywheel resistance training for spaceflight, its reliance on rotational inertia, and how it creates continuous concentric and eccentric loading, enabling eccentric overload.
Research Gaps and Rationale for the Flywheel Training Research Topic
Identifies the limited physiological evidence and implementation challenges that motivate the dedicated Research Topic, calling for studies on mechanisms, load quantification, and ecological application.
Methodologies for Load Quantification and Individualization in Flywheel Exercise
Summarizes Martín‑Rivera et al.'s validation of mean concentric linear velocity and RPE as tools to quantify inertial load and personalize prescriptions.
Performance Enhancements from Accentuated Eccentric Flywheel Training
Covers Weng et al.'s findings on improved running economy and neuromuscular function, and Maroto‑Izquierdo et al.'s comparison of submaximal vs supramaximal eccentric loads on strength, lean mass, and hormonal responses.
Opinion and Guidelines on Flywheel Periodization and Testing
Details Beato et al.'s periodization framework for team sports and Maroto‑Izquierdo et al.'s recommendations for load monitoring, testing protocols, and future research directions.
Reliability, Inertia‑Power Relationships, and Practitioner Perspectives
Presents de Keijzer et al.'s reliability data on peak power across different inertias, the distinct inertia‑power profiles of leg curl vs hip extension, and a therapist survey revealing adoption rates, perceived benefits, and barriers such as cost and evidence gaps.
Editorial Conclusions, Funding, and Conflict of Interest
Synthesizes the collective contributions, outlines future research needs, and provides transparency on author contributions, funding sources, and disclosed conflicts.