Every advantage matters when you're swimming, but the most expensive wetsuits can cost as much as a round-trip ticket to the moon, so it's key to have an option like the Blueseventy Reaction Women's Wetsuit. It's not as space-age as the top-of-the-line Helix, but it costs about half as much and still delivers all the buoyancy, flexibility, and comfort you need to hit T1 in personal-record time. The Reaction isn't designed for beginners, by any means, so it doesn't waste too much time on enhancing proprioception (the exceptions are the ultra-thin Honeycomb forearm panels, which are designed to increase awareness of arm positioning, in turn boosting power, enhancing technique, and reducing injury risk). Instead, it focuses on buoyancy and flexibility, the characteristics most important to top-quality athletes. To that end, Blueseventy employed thinner Yamamoto neoprene on the arms and lower legs, in addition to thin and stretchy Reactive Stretch Technology (RST) on the upper arms, deltoids, and shoulders. This provides serious mobility in the water, along with the shoulder freedom that's essential for powerful strokes. The RST panels are also coated with SCS, a hydrophobic friction-reducing layer that lets you cut through the water like a hot knife through butter. Thin 2mm side panels and gusseted underarms improve fit and ease core and shoulder rotation, while the split VO2 chest panel is anatomically matched to the lungs, providing tons of stretch during respiration while maximizing buoyancy. Ah, the "B" word. Buoyancy is perhaps the most important wetsuit feature for serious triathletes, as it reduces the percentage of your body that's actually moving through the water, in turn minimizing drag and maximizing efficiency.