Because I anticipate racing locally, swimming with a wetsuit in the Northwest is a no- brainer. Who wants to be cold? My problem? Never been in one before!
I had help from two people coaching through the "sausage casing" feeling of squeezing into a size small wetsuit. By height and weight, I'm on the cusp on the sizing chart for TYR between a women's small and a small/medium. I tried on a friend's wetsuit she put up for sale, skeptical that it would fit. At the rate of weight loss I've been experiencing, the two felt that this size would be fine.
As with any exercise program, consult with a physician or a certified fitness trainer. I have ran several races at 5K, 10K, 15K, and half marathon distances. By May 31, 2013, I will have completed my first 30 mile bike ride and an open water swim practice.
Added: I completed Ironman Mont-Tremblant on August 21, 2016 and am currently training for Ironman Canada on July 29 2018. I leaned out from the training and from Celiac Disease, so getting into a wetsuit is pretty easy because of the unanticipated weight loss.
In this video, we didn't use any body lubricant because this was just a fitting. You can use Glide spray on places like the shins and forearms to help get yourself into a suit. More importantly, don't get in when you're wet. Also, gloves can help you grab the material without risking nicks because of your fingernails. If you do nick your suit, you may be able to repair it with kit that includes an adhesive and backing. I took mine to a multi-sport store, and they did a repair quickly for less than $15 and it held well.
Note: I bought a second wetsuit, a Blue Seventy Axis women's sm/m full wetsuit, which puts more of the buoyancy around the thighs (where most people tend to need it!) and less in the arms. I get a better range of motion, and it accommodates my current weight as I slowly drop over the course of my triathlete training program. I bought it NEW for $125 from a person who wanted to sell it quickly. So now I have two wetsuits for both the lean time of my training season, and the times when I'll need to bulk up my thighs through strength training to become stronger (next year, bumping up to longer distance triathlons).