keep up
verb.
maintain a required pace or level
He could not keep up and dropped out of the race
verb.
lengthen or extend in duration or space
We sustained the diplomatic negotiations as long as possible|prolong the treatment of the patient|keep up the good work
Synonym: prolong, sustain
verb.
keep in safety and protect from harm, decay, loss, or destruction
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
verb.
keep informed
He kept up on his country's foreign policies
verb.
prevent from going to bed at night
The anticipation of the trip kept the children up all night|I kept myself up all night studying for the exam