1. keep up

maintain a required pace or level

Example Sentences:
'He could not keep up and dropped out of the race'

2. keep up, prolong, sustain

lengthen or extend in duration or space

Example Sentences:
'We sustained the diplomatic negotiations as long as possible'
'prolong the treatment of the patient'
'keep up the good work'

• prolong
• sustain

3. conserve, keep up, maintain, preserve

keep in safety and protect from harm, decay, loss, or destruction

Example Sentences:
'We preserve these archeological findings'
'The old lady could not keep up the building'
'children must be taught to conserve our national heritage'
'The museum curator conserved the ancient manuscripts'

• conserve
• maintain
• preserve

4. follow, keep abreast, keep up

keep informed

Example Sentences:
'He kept up on his country's foreign policies'

• follow
• keep abreast

5. keep up

prevent from going to bed at night

Example Sentences:
'The anticipation of the trip kept the children up all night'
'I kept myself up all night studying for the exam'