Trainers will survive washing in the washing machine, and even come out nice and clean. But if they are too heavy you risk damaging the plastic paddles in the drum. Especially with cheaper washing machines.
So washing trainers in a front loading washing machine can cause the plastic drum paddles (sometimes called drum lifters) to come loose or even break. This in turn can cause damage to laundry that subsequently snags on the sharp holes revealed.
Having said all that, some washing machines now have special programmes for trainers. If yours does and the drum paddles break I would complain to the manufacturer. Or if you get nowhere, complain to the retailer under the sale of goods act. Clearly if they provide a special programme to wash trainers then washing machine must be capable of carrying out the wash without breaking.
Washing trainers could now be more dangerous
Recent developments have seen some manufacturers making washing machines where the drum paddles (or lifters) can no longer be replaced. With some you can’t even replace the drum because the drum cannot be taken out due to having a sealed outer tub. This makes washing trainers in a washing machine even more risky because if a paddle breaks on one of these the machine is as good as scrap.
Is a special trainer wash bag the answer?
I’ve seen several nesh bags claiming they protect the washing machine whilst washing trainers but I’m at a loss as to how. The ones I’ve seen are just net bags with a little bit of slightly padded material every inch or so all around. The damage trainers can cause to a washing machine is when they get tossed around as the drum rotates. They may get taken up to the top of the drum and then fall down onto a paddle.
If they are pretty light they may be OK, but the potential is to damage cheap plastic paddles on poorly made washing machines or work them loose by continually hitting them during washes. I would have though that placing them together in one bag would double the weight and make them more likely to damage the paddles? I wouldn’t have thought the light padding would help much.
Broken drum paddles?
If you have loose or broken drum paddles you can buy them here Washing machine drum paddles (or lifters)