exeecise可数吗

例句：

Exercise tones up your body.

运动强健身体。

Riding a bike is great exercise.

骑自行车是很好的'锻炼。

Swimming is good exercise.

游泳是有益的运动。

How often do you exercise?

你多长时间锻炼一次？

Swimming is a good form of exercise.

游泳是很好的锻炼方式。