Are you able to physically relax your body when you go on rides?
I'm not a huge roller coaster guy, so I actually hadn't gone on any rides during all of my adult life until I recently visited Linnanmäki while travelling in Finland.
I tried all the rides, but I was seriously scared for my life during a few of them, especially Ukko (someone else's POV video).
Rationally I realize that these rides must be designed in such a way that it's impossible to fall out even when hanging upside down, but I clearly remember feeling that if I relax my body and stop holding on for dear life, I will definitely fall out.
For people who go on rides more often, do you manage to overcome this feeling and actually relax your muscles while you're on a ride?
It depends on the ride. On something smooth and comfortable like a B&M hyper I can definitely relax. For example, Candymonium at Hersheypark is a great ride to practically ragdoll on. Also, putting hands up is a good start even if you're tensed up. When you realize on some level that holding on isn't doing anything but letting you tense your muscles unnecessarily you'll start to feel more freedom on rides. Also, as you become more familiar with ride forces, you can better predict how upcoming elements will feel and you can brace for them in a more relaxed way, rather than trying to stay totally rigid in your seat
Not a coaster, but on an S&S screamin' swing I notice that I tense up totally involuntarily. Something to do with the amount of airtime and the feeling of the restraint. It really depends on the ride.