sit-up

sit-up — noun

1. a physical exercise where you lie on your back with bent knees and raise your up

1.nounB1
Definition

a physical exercise where you lie on your back with bent knees and raise your upper body toward your knees, used to make the muscles in your stomach area stronger

Example

After just two weeks of daily sit-ups, Aisha noticed her stomach felt firmer.

collocation: daily sit-ups

The coach asked the team to do three sets of twenty sit-ups during practice.

collocation: do + [number] + sit-ups

Common collocations
  • do sit-ups
  • a set of sit-ups
  • twenty sit-ups
  • daily sit-ups
Synonyms
  • crunch

    a shorter, more controlled version of a sit-up that only lifts the shoulders off the ground.

  • ab curl

    less common term for an abdominal exercise, often used in gym settings.

Grammar Patterns

do + sit-up(s)

a set of sit-ups

Usage Note

Often used in the plural form (sit-ups) even when referring to the activity in general, as in 'I do sit-ups every morning.'

Common Mistakes

I did sit-up this morning.
I did sit-ups this morning.
The exercise is almost always referred to in the plural form, even when doing just one repetition.

sit-up — phrasal verb

sit-up — verb

Word family

Synonym discussion

Sense: verb/1

All four expressions describe moving from a lower to a higher position, but they differ in scope and register. 'Sit up' specifically means lifting only the upper body from lying or leaning — the lower body stays where it is. 'Get up' is broader and much more common; it can mean standing up from any position (sitting, lying, kneeling) and is neutral in register. 'Rise' is more formal and literary, often used in narratives ('She rose from her chair'), and can also mean standing up rather than just sitting up. 'Sit upright' focuses primarily on posture — arranging the back straight while already seated — rather than on the motion of coming up from a lying position. For example: 'After falling on the ice, Dmitri sat up slowly before attempting to stand.' Here 'sat up' is the precise first-stage action; 'got up' would jump straight to standing, 'rose' would sound too formal for the scene, and 'sat upright' would not capture the transition from lying.

sit up ↗get up ↗rise ↗sit upright

Common collocations

Nouns

Adverbs

Phrases

  • in bed
  • on the floor
  • from a lying position
  • past midnight

Prepositions

Etymology

Old EnglishModern English

The word 'sit-up' developed from the verb phrase 'sit up,' combining 'sit' (from Old English sittan, meaning 'to be seated') with 'up' (from Old English up/uppe, meaning 'to a higher position'). The noun form, referring to the abdominal exercise, emerged in American English around the mid-20th century, taking the hyphenated compound form 'sit-up' to distinguish the specific exercise from the general action of sitting up.