For A/B Cups
Ryka's super-soft Cross Over Heart Song Top ($19; ryka.com) keeps you cool and dry.
Runner-up: Speedo Axcelerate Spliced Sport Bra ($46; speedousa.com).
For B/C Cups
Nike's Seamless Short Sport Top ($36; nikewomen.com) prevents chafing while minimizing bounce.
Runner-up: New Balance Skye Crop ($38; newbalance.com).
For C/D Cups
Champion's 02Cool bra has mesh panels to keep you sweat-free ($36; championcatalog.com).
Runner-up: Response Crop Top from Adidas ($36; shopadidas.com).
For D Plus Cups
The Fiona sports bra from Moving Comfort ($44; movingcomfort.com) is engineered for larger-breasted women.
Runner-up: Vassarette Flir-T Bra ($10; Wal-Mart).