A wetsuit needs to fit snugly: if it’s too loose it’ll allow water into the suit that’ll seriously slow you down. If it’s too tight, your swimming experience won’t be pleasant. When trying on in a shop, the suit should feel tight but not restrictive.
Once it’s on correctly (not bunched up around the crotch or under the arms), there should be no air pockets or creases in the neoprene. Perform some shoulder swings and front-crawl arm strokes. This will help to give you an idea of whether it’s too tight around the shoulders. Your chest and arms need to be able to move freely.
A wetsuit purchase is an important one so allow plenty of time to try on plenty of different brands. There’s little parity between manufacturers, so look closely at sizing charts and, if possible, take along a knowledgeable triathlete friend who can offer advice.
Your decision on when to upgrade your suit could be dependent on how well you’ve looked after your original suit and at what level you’re competing. If cared for correctly, a wetsuit should last for several seasons.
Always rinse it after each use; store flat and avoid using petroleum-based lubricants. Wear and tear is inevitable, though, so it’s time to upgrade when the suit has nicks or tears that cannot be repaired. If you bought an entry-level suit and you’re now looking to race more often, you should consider a top-end or mid-range suit
It’s worth remembering that a lot of the mid-range suits from the best-known brands usually boast almost as many snazzy features as the expensive top-end ones, and perform almost identically.