Not an endurance rider, but I carry out on trail (hogs, bears, gators, meth heads … Oh my!). I’ve found a lot of the conceal carry options do not work for a short, petite woman. For example, thunder wear and the T-shirts just don’t work if you aren’t a bigger person imo.
I carry a Ruger LCR 38 revolver. I have carried my S&W 357 magnum, but that’s too big and too heavy. I use a “in the pants” holster and have it aligned to the center of my spine. I wear breeches, so that’s an extra “hold” for it, but it definitely needs a belt for stability.
This has been the only thing that works for me. Unfortunately, even my LCR looks like a tumor out if control on me, so for every day carry, I have to go to my concealed weapon purse.
Never put a weapon on your horse. If your horse throws you because of a wild animal or meth head, you’re left unprotected.
I have not fallen with my revolvers or my semi auto (which I have since sold), but it would stand to reason you’re less likely to get hurt if it is center mass of you body vs off center. Think about how you typically fall to one side or the other. I’ve rarely seen anyone pancake one way or another. As animals, we typically fall to one side to protect vital organs, and because we’re falling off one side or another from another animal. Even tripping straight down while walking, humans won’t just pancake, they roll to protect themselves. If you have a gun on your hip or off center, you’re more likely to break a hip than protect your spine imo
And make sure, if you have a semi auto, you have safety on or a bullet not in the chamber.
BTW, love the newish legislation of carrying in parks!