Muller's exercises
/ˌmʊləz ˈɛksəsʌɪzɪz/(also Muller exercises)
noun
A set of gymnastic and respiratory exercises developed and promoted by J. P. Muller, intended to maintain good physical health and muscle tone.
Origin
Early 20th century. From the genitive of the name of Jörgen Peter Muller, Danish physical educationalist who developed and promoted these exercises + the plural of exercise. In some forms from Muller + exercise.