What suit do you train in?

The 100% polyester suits would last forever except the seams end up giving out, as mentioned by Fortress. My TYR poly mesh drag suit just split the seam at the crotch a couple weeks ago. Other than that you'd think it was brand new! I guess if you're a good seamstress maybe they will last forever. I always used to use 100% nylon suits. They last quite a while, but fade in color quickly. Don't use a suit that contains lycra for practice purposes. Assuming the manufacturer used polyester for all four threads (two needles, upper and lower looper), the tensions were set correctly, and the suit was the correct size, the seam should last as long as the polyester fabric. I have a polyester Chloroblock suit that I made two years ago, and apart from the lining bagging out (it's nylon) and a bit of fading, it's still usable. And that was made on a household serger that wasn't of the best quality, not an industrial model. Could be they used nylon "wooly" for the loopers. It gives a very stretchy seam but doesn't seem to hold up to chemicals as well. Wooly is the stuff that looks sort of "fluffy" and is usually only used for the looper threads (the ones that wrap around the outside edge). If the wrapping threads look smooth and no different from the needle threads (check the top stitching for comparison) then it was most likely sewn with all polyester thread and may last a bit longer. I say "may last" because I don't personally believe serger seams are as inherently strong as some sewing machine seams. Sergers are mainly used in industry because they are so fast. We have salt water pools here which aren't as hard on suits (or sinuses) but even with that, I've noticed that lycra varies widely. Some lycra fabric lasts almost a year, others are only good for a few months. As to whether a suit will last longer if it fits loosely - probably not. You have more fabric waving in the current and catching, so more stress on the fibers rather than less.

The 100% polyester suits would last forever except the seams end up giving out, as mentioned by Fortress. My TYR poly mesh drag suit just split the seam at the crotch a couple weeks ago. Other than that you'd think it was brand new! I guess if you're a good seamstress maybe they will last forever. I always used to use 100% nylon suits. They last quite a while, but fade in color quickly. Don't use a suit that contains lycra for practice purposes. Assuming the manufacturer used polyester for all four threads (two needles, upper and lower looper), the tensions were set correctly, and the suit was the correct size, the seam should last as long as the polyester fabric. I have a polyester Chloroblock suit that I made two years ago, and apart from the lining bagging out (it's nylon) and a bit of fading, it's still usable. And that was made on a household serger that wasn't of the best quality, not an industrial model. Could be they used nylon "wooly" for the loopers. It gives a very stretchy seam but doesn't seem to hold up to chemicals as well. Wooly is the stuff that looks sort of "fluffy" and is usually only used for the looper threads (the ones that wrap around the outside edge). If the wrapping threads look smooth and no different from the needle threads (check the top stitching for comparison) then it was most likely sewn with all polyester thread and may last a bit longer. I say "may last" because I don't personally believe serger seams are as inherently strong as some sewing machine seams. Sergers are mainly used in industry because they are so fast. We have salt water pools here which aren't as hard on suits (or sinuses) but even with that, I've noticed that lycra varies widely. Some lycra fabric lasts almost a year, others are only good for a few months. As to whether a suit will last longer if it fits loosely - probably not. You have more fabric waving in the current and catching, so more stress on the fibers rather than less.