1.
If you work yourself up , you make yourself feel very upset or angry about something.
She worked herself up into a bit of a state...
Don’t just lie there working yourself up, do something about it.
PHRASAL VERB : V pron-refl P into/to n , V pron-refl P
see also worked up
2.
If you work up the enthusiasm or courage to do something, you succeed in making yourself feel it.
Your creative talents can also be put to good use, if you can work up the energy...
PHRASAL VERB : V P n (not pron)
3.
If you work up a sweat or an appetite, you make yourself sweaty or hungry by doing exercise or hard work.
You can really work up a sweat doing housework...
PHRASAL VERB : V P n (not pron)
4.
If you work up something such as a piece of writing, you spend time and effort preparing it.
I sketched the layout of a prototype store and worked up a business plan...
PHRASAL VERB : V P n (not pron)