You have a choice of coed or single-sex swimming exercise classes.

你可以选参加男女混合或是非混合的游泳练习课。

《柯林斯英汉双解大词典》

Swimming is good exercise.

游泳是有益的运动。

《牛津词典》

Swimming is a good form of exercise.

游泳是很好的锻炼方式。

《牛津词典》

There is a debate about whether or not swimming burns as many calories as other forms of exercise.

VOA: special.2010.06.08

Swimming is said to be one of the best ways to exercise.

VOA: special.2010.06.08

At 76, looking more striking than she had in her 50s, she was swimming exercise laps at the Ritz Hotel, a few blocks from her embassy residence, when she fell ill and collapsed.

CNN: Her Brilliant Career

Swimming is amazing exercise, not only for toning all aspects of the body but also for burning calories, mastering the breath, and quieting the mind.

FORBES: How Cross-Training Can Make You A Better Swimmer: What Is The Best Technique Of Swimming The Crawl?

So the advice we give to all pregnant women during pregnancy is to try and avoid getting too hot, whether it's just during exercise or swimming in a warm pool.

BBC: Exercising during pregnancy