How should your wetsuit fit?
Wondering how do you know a wetsuit fits properly, especially when buying in a shop with no water, when you should you upgrade? Here's Emma-Kate Lidbury with the answers

A swimming 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. Here’s how to make sure you get enough bang for your buck when it comes to picking the right wetsuit for you.
When trying on a triathlon wetsuit 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.
Make sure it fits properly by performing some shoulder swings and front-crawl arm strokes. As you do these exercises, consider whether it rubs or pinches anywhere. 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.
How do I know if my wetsuit fits properly?

Your wetsuit fits properly when it is comfortable to wear in and out of the water. Some chafing and rubbing are often inevitable when swimming in a triathlon wetsuit for an extended period of time, but a good-fitting wetsuit will mitigate the effects.
A wetsuit works by trapping a layer of water between the body and suit, which is warmed up by core body temperature and acts as insulation to colder waters. A triathlon wetsuit has varying thicknesses within the suit to raise the body up in the water into a hydrodynamic position for the most efficient swim line.
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 and let it dry (you could use a wetsuit-specific hanger for this); store flat and avoid using petroleum-based lubricants. Wear and tear’s 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 triathlon wetsuit or a mid-range wetsuit.
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.