I've been working out, mostly by running, on again and off again (mostly off again) for a few years now. In all that time, I've never had a particularly good sports bra, always relying on random ones without underwires or band and cup-denominated sizes from Nordstrom Rack. For me, those are fine for yoga, pilates, and the like, but for movement-heavy cardio like running or even the elliptical, there is always more than a bit of... undesired movement. The bouncy-ness, if you will, has never been enough of a problem to be a real factor in whether I work out or not. It was also never enough to actually get me to invest in something more substantial. I don't know if I'm an outlier, but I've generally found that all that undesired movement is much less uncomfortable than it looks. I barely notice it while working out except when I catch a glimpse of myself in a mirror.
This month is definitely not another no-shopping month for me, and one of the things I've obtained is a better sports bra to go with my renewed interest in keeping to a fitness routine. I ordered a few designs and sizes to try out, and I must say, sports bras that use bra sizing are not an easy thing to shop for. I'm pretty confident that I've been correctly sized for bras, and I read the reviews for each design closely to know whether to size up. One thing that I wasn't used to was the more complicated designs (adjustable straps with clips and/or bands with hooks and eyes where I've only worn sports bras that slipped over the head with elastic). I didn't end up being that close with ordering the right sizes, for the most part. If I had to generalize, these designs seem to run smaller, sometimes much smaller, than expected in the band.
I did get the sizing right with the Panache Underwire Sports Bra (it runs true to size, but the band starts out quite snug) and it was my favorite design out of the ones I tried, with no clips for the straps, just a hook and eye closure in back for the band. The band is still a bit tighter than I'm used to, which I think is supposed to be the case with a sports bra. It is quite expensive, almost shockingly so relative to what little I normally spend on activewear, but it feels worth it so far. I wore it out to today's workout and it did its job well.