Don't strain yourself informal
To not cause inconvenience or problems for someone when he or she does something, often used in a ironic way
Don't strain yourself, I can handle it myself.
This box is very light, but don't strain yourself. I'll move it.
You need to take a break, don't strain yourself too much.
To try very hard to do something
someone will be successful.
With her talent writing, Kathy is definitely going places.