When I bike, hike, jog, kayak, etc. I have my Glock 19 on me. Usually appendix. Never been an issue and been almost a decade.
Since you're talking LCP sized, I'd recommend a Glock 42 (.380ACP) or 43 (9mm). I had a co-worker who would carry an LCP in his pocket and it began to rust all over the slide. Months went by and he said "screw it" and got a LC9 that he carried appendix as well. In about a month and 700 rounds later, he had rust all over the LC9 as well.
Glock has some wizardly magic going on with their finish along with being polymer too, of course. I've had 1911s and SIGs rust like you wouldn't believe. I'm not a fan of Ruger and never have been. But seeing my co-workers guns do that sure didn't help much.