Being frugal and workout clothes

This issue has been on my mind recently because I've noticed my sports bras haven't been doing their job as well as they used to.  And when I began to think about it, I realized that I've been using a bunch of then since I started running more than 2 years ago.  And I started thinking about my active wear and realized that I have workout pants I've had for more than 10 years.  Though I promise I don't go out in those, I still use them for at home work outs. And my workout tops tend to be mostly race shirts since they're free and I might as well use them anyway.

Old work out pants from when I was in school - they're even cotton!

Sigh.  I think in the back of my mind I still feel like clothes I'm going to sweat in aren't really worth paying much for.  I'm working on changing that mind set.  And also working on ways to still be frugal about buying workout clothes.  I've been keeping an eye out on sales.  Earlier this year, there was a great sale at Under Armour and I got a pair of cold weather leggings that I love.  I've also gotten some great deals at Fabletics on gym clothes.  Yesterday, I was able to use some Old Navy coupons I had on new sports bras and a pair of running capris.

Shelby inspecting my new clothes from Old Navy

But I'm still figuring out the right balance there.  I bought another pair of Under Armour leggings on sale through Amazon and wore them out on a run for the first time this past weekend.  And I could tell that they would cause chafing on any runs longer than 3-4 miles.  So I guess they'll be reserved for short runs.  And maybe not so much with the online purchases for things like that.  I might just have to keep an eye out for sales/coupons for physical stores where I can try things on.

I'd love to hear any tips for saving money and still changing out workout clothes as needed.  I've read that sports bras should be switched out approximately every 6 months but that seems so wasteful.  What do you think?  How about things like leggings and tops?