1. to train the body by physical exercise 鍛煉身體；做運動
I work out regularly to keep fit.
我經常做運動以保持健康。
—related noun workout
2. to develop in a successful way 成功地發展
My first job didn't work out.
我的第壹份工作幹得不好。
Things have worked out quite well for us.
事情的結果對我們很不錯。
take exercise：做體操，做健身活動；鍛煉
所以work out不等於take exercise，但work out 有 成功地發展 之意。