Overexert

Don't overexert yourself.

I don't want you to overexert yourself.

Please be careful not to overexert yourself.

Don't overexert yourselves.

Your fever has only just come down so don't overexert yourself.

Take care of your joints; don't overexert yourself.

“But the real trick”, he said, “is to make sure you don’t over-exert yourself in the first place.” The key to post-exercise chic is simply not to sweat. Of course, it’s the first rule of style. Never, ever overdo it.