A quality wetsuit is designed to trap a layer of insulating water next to your skin and is essential for open water swimming in colder temperatures, including triathlon training and competition. Wetsuits designed for swimming/triathlon are lighter and less restrictive than diving or surfing wetsuits and use a blend of neoprene and rubber or nylon to offer a balance of thermal insulation, mobility, buoyancy, durability and reduced drag (hydrodynamics). The type of triathlon wetsuit you require will depend on the conditions – colder temperatures will call for a full-sleeve suit with thicker neoprene (up to 5mm) providing good thermal insulation. In warmer temperatures a thinner, knee-length or sleeveless wetsuit or lightweight tri suit will offer increased flexibility and range of movement, especially around the shoulders. Whichever wetsuit you choose, it’s essential that it fits correctly, particularly around the shoulders and hips.