**5. Conclusions**

Collectively, greater muscle elongation at the mid-belly and the distal part of GM during static stretching, and greater ankle angles at rest and during dorsiflexion were observed in FT compared to FNT female athletes, aged 8–10 years. These findings indicate that between children with different flexibility training history, muscle architecture differs only during stretching, and that there are non-uniform adaptations along GM length depending on training history. Albeit speculative, increased muscle fascicle elongation may represent an early-stage adaptation to stretching-induced increases in resting fascicle length found in flexibility trained, female adult athletes compared with not trained controls.

**Author Contributions:** Conceptualization, O.D., I.P., and G.C.B.; methodology, I.P., O.D., G.C.B., P.S., and G.T.; data curation, I.P., O.D., V.G.; writing—original draft preparation, O.D., I.P., A.D., writing—review and editing, O.D., G.C.B., and G.T.; supervision, O.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** The authors received no external funding.

**Acknowledgments:** The authors would like to thank the athletes for their dedicated time and collaboration.

**Conflicts of Interest:** The authors have no conflict of interest to declare
