AUTHOR=Langan Sean P. , Grosicki Gregory J. TITLE=Exercise Is Medicineā€¦and the Dose Matters JOURNAL=Frontiers in Physiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.660818 DOI=10.3389/fphys.2021.660818 ISSN=1664-042X