If you're a bigger chest size, you may want a different bra for high-impact sprints, etc. I'm a 34C and this works well for the gym, a hike or just daily wear. I can fit into a small, but the medium is more comfortable - not too tight, not too loose and no uni-boob. The material is thick enough not to be too sheer, but not as thick and scratchy as the regular sports bras. I thought the Patagonia capilene bras were the most comfortable, but these are as good and cheaper.

I had two, now I've ordered two more. I have a wide array of bras in my wardrobe, but these are the ones I keep reaching for. They transition well from the gym to daily wear and formal attire.