Do PBT suits stretch out?

[JamesSwim]

Do suits made out of poly and PBT stretch over time? I have some suits made of poly/PBT that used to feel a bit too small, but they feel right now. The suits are several years old and have been used for swimming

There's a chance I may have lost weight, but wondering if it's the suit.

Since PBT fabrics are somewhat elastic, perhaps they stretch out over time?

It seems that 100% Nylon suits do not degrade or stretch over time.

Even though suit makers state that PBT/poly suits are long lasting, they may want them to not last forever, and encourage us to buy replacements.

[Torchwatch]

Any synthetic fabric will contain a plasticiser, as the fabric ages the plasticiser breaks down and fibres with the fabric snap and break. With broken fibres in the weave the fabric will appear to stretch and no longer pull back to it's original size.

The only way to prove or disprove that your suits have become looser is to buy a brand new identical suit and see if it is tighter or looser on you. Knowing your previous and current body weight and waist sizes would help discover if you have actually reduced yourself by a suit size.

[Dooley67]

JamesSwim,

I just noticed last week that some of my suits felt a little looser on me. For me, I know I've lost 11 pounds since I bought the suits and dropped from a 32 waist to a 30. The suits are all either 30 or Medium. It's possible, like Torchwatch wrote, that the fabric has broken down a bit, but I wonder if 6 months of swimming in each suit 1-2 times a week would be considered a long enough period for the fibers to have broken down. What do you think Torchwatch?

D67

[Torchwatch]

If you are fitter and slimmer then maybe it is time to downsize.
If the downsized suit is too tight then make it your next objective to become slim and fit enough to fit into the suit.

A sign that fibre breakdown is taking place is that the crotch of the suit begins to hang down to your knees. I remember seeing this quite often in young club swimmers who had worn out their training suits and not got around to replacing them.

[JamesSwim]

Originally Posted by Torchwatch

If you are fitter and slimmer then maybe it is time to downsize.
If the downsized suit is too tight then make it your next objective to become slim and fit enough to fit into the suit.

A sign that fibre breakdown is taking place is that the crotch of the suit begins to hang down to your knees. I remember seeing this quite often in young club swimmers who had worn out their training suits and not got around to replacing them.

You're right, as some suits do sag a bit. I also noticed that even the PBT suits have lost some of their spring - if you stretch them, they don't snap back quickly.

But I've become a bit slimmer too, on top of that, so I'll downsize as you recommend.