How often should I do exercise?

我应该多久运动一次？

It is really good to do exercise.

做运动真的很好。

I take out a skipping rope and do exercise.

我拿出一个跳绳做运动。

He eats unhealthy food and doesn't do exercise.

他吃不健康的食物并且没有做锻炼。

I'm so exhausted that I can't do exercise anymore.

我太累了以至于再也没法锻炼了。