The old AirPods didn't come out of my ears when I was running or cycling, but it depends on the condition of your ears. For weight training, it depends on how hard you move. When bench pressing or generally doing sports where you move the upper part of your body, including your head, the AirPods might fall out. You can check how tightly they fit and if they don't fit well, you can send them back to Digitec. This is a product for which I have taken out Digitec device insurance, as it can happen that the AirPods fall out. They are usually not broken after falling off, but better safe than sorry.

Yes, but they may not 'fit' your ears. They may fit just as well as fall out many times.