Just heard about this one:

One for the Mums: AQUA AEROBICS. Aqua aerobics classes are an excellent form of non weight bearing exercise, suitable for all levels of fitness and ages. Emphasis on cardiovascular, muscle toning, flexibility, mobility and conditioning, using the water's resistance, provides an all round physical workout. Days and Time: Tuesdays & Thursdays at 8.30am Venue: PIA's 50m Pool. Cost:400thb per session. Contact:Debbie Jones on debbie@phuketinternationalacademy.com