I have been very stressed lately and have been using yoga as exercise to relieve my stress 
I have heard that yoga can help with that
Yep, its often used for therapeutic purposes because its a low impact exercise.
Yeah and stretching feels really good!
You're right, and especially when you combine it with meditation, imagery, breath work and music.
Yeah. have you ever tried swimming ?
I have only heard of the more classical approaches of swimming, such as freestyle and butterfly.
 I have heard it can help with stress too
I see, perhaps I should use it as a supplementary exercise practice.
You should look into it!