Editing Crunch (exercise) (section)

{{Short description|Abdominal exercise}}
[[Image:FloorCrunch.JPG|thumb|right|300px|Performing the crunch]]
The '''crunch''' or '''curl-up''' is an [[abdominal exercise]] that works the [[rectus abdominis muscle]].<ref>{{Cite web |title=Core Anatomy: Muscles of the Core |url=https://www.acefitness.org/fitness-certifications/ace-answers/exam-preparation-blog/3562/core-anatomy-muscles-of-the-core/ |access-date=2022-03-28 |website=www.acefitness.org |language=en}}</ref> It enables both building and defining "six-pack" abs and tightening the belly. Crunches use the exerciser's own body weight to tone muscle and are recommended by some experts{{Like whom?|date=June 2023}}, despite negative research results{{Citation needed|date=June 2023}}, as a low-cost exercise that can be performed at home.<ref>{{Cite web|title=Exercising on a budget|website=MedlinePlus Medical Encyclopedia|url=https://medlineplus.gov/ency/patientinstructions/000762.htm|access-date=20 April 2020}}</ref> Crunches are less effective than other exercises such as [[Plank (exercise)|planks]] and carry risk of back injury.<ref name=atlantic/>