AUTHOR=Willis Sarah J. , Borrani Fabio , Millet Grégoire P. TITLE=High-Intensity Exercise With Blood Flow Restriction or in Hypoxia as Valuable Spaceflight Countermeasures? JOURNAL=Frontiers in Physiology VOLUME=10 YEAR=2019 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2019.01266 DOI=10.3389/fphys.2019.01266 ISSN=1664-042X