literally: “muscle tomcat” / meaning: aching muscles
More than 10 million Germans belong to a fitness club. Many of them display iron German discipline, never leaving the gym before having completed their third set of selfies. Those who go there to actually work out are rewarded with lots of body pain the next day. A genuine Muskelkater, as Germans like to put it.
Just like its English counterpart, the word Muskel evolved from Latin “musculus,” which means “little mouse.” That’s probably because the ancient Romans believed that flexing your biceps looks a bit like a little rodent running under your skin. Surprisingly, the -kater part has nothing to do with animals at all, but is derived from “catarrh.” This word originally referred to an inflammation of the mucous membranes and was later used to describe a headache after you had too many drinks.
Hence, linguistically speaking, the “muscle tomcat” is more like a “little mouse hangover.” The good news is, if you pay your gym fees solely to show off your new yoga pants on Instagram, you will most likely never suffer from one.
References:
https://de.statista.com/statistik/daten/studie/5966/umfrage/mitglieder-der-deutschen-fitnessclubs
https://de.wiktionary.org/wiki/Muskel
https://www.dwds.de/wb/Kater