A one-piece made for lap swimming is your best bet.

Yes. For both water aerobics and lap swimming, get a one-piece swimsuit (or jammers/briefs if you’re a guy) made from chlorine-resistant fabric like polyester or PBT.

Water aerobics involves a lot of bending, jumping, and kicking. A bikini will shift, and a loose suit will fill with water and drag. A lap-swim cut—like a standard racing back or a high-neck style—stays put and reduces resistance. For men, jammers or briefs beat board shorts every time because board shorts weigh you down and chafe.

The big thing is fabric. Most fashion swimsuits use nylon/lycra, which absorbs chlorine and breaks down fast. A polyester suit from Speedo, TYR, or Arena will outlast three fashion suits and cost about the same over time. You don’t need a $200 carbon-fiber race suit—just something built to take a chemical beating.

You’re there to move