Editing Isometric exercise (section)

==History==

=== Müller and Hettinger ===

In the 1950s, German scientists Dr. Erich Albert Müller<ref>Erich A. Mueller, "The Regulation of Muscular Strength", ''Journal of the Association for Physical and Mental Rehabilitation'', 11 (March–April, 1957): 41-47.</ref> and Theodor Hettinger<ref>{{Cite journal |last=Hettinger |first=Th. |last2=Müller |first2=E. A. |date=1953 |title=Muskelleistung und Muskeltraining |url=https://link.springer.com/article/10.1007/BF00934143 |journal=Arbeitsphysiologie |language=de |volume=15 |issue=2 |pages=111–126 |doi=10.1007/BF00934143 |issn=1439-6327|url-access=subscription }}</ref> "observed that contractions involving less than about one third of maximum strength do not train the muscle.  If the contraction of a  muscle exceeds one third of its maximum strength, its mass grows and hence also its strength".<ref>{{Cite web |url=https://www.mpg.de/798250/S004_Flashback_096-097.pdf |title=Sweating in the Service of Science, Occupational Physiology |access-date=2020-08-05 |archive-date=2021-06-28 |archive-url=https://web.archive.org/web/20210628060413/https://www.mpg.de/798250/S004_Flashback_096-097.pdf |url-status=dead }}</ref> The study at the Max Planck Institute consisted of over 200 experiments over a ten-year period. Theodor Hettinger published his book ''Physiology of Strength''.<ref>''Physiology of Strength''. Theodor Hettinger, M.D. Edited by M. H. Thurwell. Springfield, Illinois, Charles C. Thomas, 1961</ref> They both developed a training program based on isometrics exercise.<ref>Crakes, J. G. (1957). ''An analysis of some aspects of an exercise and training program developed by Hettinger and Mueller''. Unpublished master's thesis, University of Oregon.</ref>

In the 1960s, professor James A. Baley put isometrics to the test with a class of 104 college students at the University of Connecticut to study the results on tests measuring increases in strength, endurance, coordination, and agility. The original article showed significant gains after a 4 week program of isometric exercises.<ref>{{Cite journal|last=Baley|first=James A.|date=1966-10-01|title=Effects of Isometric Exercises Done with a Belt upon the Physical Fitness Status of Students in Required Physical Education Classes|url=https://www.tandfonline.com/doi/ref/10.1080/10671188.1966.10614754|journal=Research Quarterly. American Association for Health, Physical Education and Recreation|volume=37|issue=3|pages=291–301|doi=10.1080/10671188.1966.10614754|issn=1067-1188|url-access=subscription}}</ref>
Isometric exercises were first brought to the modern American public's attention in the early days of [[physical culture]], the precursor to [[bodybuilding]]. Many bodybuilders had incorporated isometric exercises into their training regimens.<ref>{{cite web | url = http://www.spmessenger.com/strength/isometric.html |archive-url = https://web.archive.org/web/20080129094625/http://www.spmessenger.com/strength/isometric.html | title= Strength Training - Isometric Exercise|publisher=SPMESSENGER.com|access-date = 2008-11-10 | archive-date = 2008-01-29 }}</ref>{{better source|reason=website, no author, no references|date=September 2023}}