Warm-up and Warm-ups

Warm-up noun - A performance, activity, or event that precedes and sets the stage for the main event.

Warm-ups and warm-up are semantically related in two-piece sporting attire topic. In some cases you can use "Warm-ups" instead a noun phrase "Warm-up".

Warm-up and warm-ups are semantically related in work topic. Sometimes you can use "Warm-up" instead a noun phrase "Warm-ups", if it concerns topics such as exercise, preparation, practice, calisthenic exercises performed daily.