**5. Conclusions**

The present study demonstrated oral lactate administration-associated hypertrophy and regeneration of mouse skeletal muscle. Extracellular lactate might contribute to the regulation of skeletal muscle plasticity.

**Author Contributions:** Conceptualization, Y.O., T.E., and K.G. Investigation, Y.O., K.A., T.I., Y.S., Y.M., A.O., H.K., and S.Y. Formal analysis, Y.O., K.A., T.I., Y.S., Y.M., A.O., and H.K. Writing—original draft preparation, Y.O., T.E., and K.G. Funding acquisition, Y.O and K.G.

**Funding:** MEXT/JSPS KAKENHI Grant Number (16K12942, Y.O.; 16K13022, K.G.; 17K01762, K.G.; 18K10796; Y.O.; 18H03160, K.G.), the Uehara Memorial Foundation (Y.O.; K.G.), the Meiji Yasuda Life Foundation of Health and Welfare (Y.O.), the Naito Foundation (K.G.), the Descente Sports Foundation (K.G.), the All Japan Coffee Association (K.G.), the Science Research Promotion Fund from the Promotion and Mutual Aid Corporation for

Private Schools of Japan (K.G.), and Graduate School of Health Sciences, Toyohashi SOZO University (K.G.) supported this study.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.
