If you're looking for a lightweight fabric in a sports bra, but need maximum support then take a look at the Freya Dynamic Wirefree Sports Bra:
Perfect for high intensity workouts, Dynamic is a non-wired soft sports bra that shapes and supports the breasts through encapsulation rather than traditional compression methods. Dynamic also features seam-soft thread to reduce friction against the skin.
Fully lined cups for increased support and reduced movement. Wide flat underband elastic for added comfort and anchorage under the bust.
Adjustable built up padded strap for comfort and support. Soft hook and eye with three rows for flexible fit.
Slide hook fastening allows racer back option with quick and easy dressing.