AUTHOR=Montenegro Arjona Oscar Alfredo , Montenegro Arjona Jairo , Blasco Lafarga Cristina , Cordellat Ana TITLE=Commentary: The polarization-index: a simple calculation to distinguish polarized from non-polarized training intensity distributions JOURNAL=Frontiers in Physiology VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2023.1179769 DOI=10.3389/fphys.2023.1179769 ISSN=1664-042X