What I wore for my first (and so far only) sprint tri is cycling shorts and a running bra top. Both were items I already had. The bra was a color that I didn't mind wearing by itself (not that I'm that modest ). I took a couple of pairs of cycling shorts that I thought were likely candidates and wore them into the shower to find out how much water the chamois took on, and how much the fabric sagged when wet. The pair I chose worked fine for the race.