[Kaderin Triste]

Well, having extra thickness from polish can help with it, but it's not foolproof. I still break and chip my nails even when they're polished, but I find myself being more careful when they "look pretty".
There are also nail hardeners/thickeners you can use, but those can also make the nails brittle.
My nails currently are like a good pie crust, thin, crisp(brittle), and flaky.
I've started taking multivitamins again, which, though not an ideal solution, will help with some of the deficiencies from my poor diet that add to the condition of my nails. I also have been trying to remember to use oil to keep them moisturized so they're more likely to bend, not break.
And polish also has the benefit of helping create a barrier against water, which can also be bad for nails. But it's not a perfect seal so keeping hands out of water as much as possible is recommended, though not always avoidable.
I should start taking an oil pen with me to apply throughout the day as well probably.