I try to keep it minimalistic when going for a run, I don’t like wobbling around with Ipods, water bottles, keys etc. I won’t bother you with the details of my Ipod struggles (I keep losing the earphones and the wire either strangles me or slaps me across the face all the time), but I am going to share the solution to my key aversion.
When I’m wearing my running tights it’s not really a problem, they have a pocket with a zip on my bum, which feels weird at first but now I’m running with my keys,my cellphone and other rubbish on my bum when I’m wearing those ;).
When I’m wearing less fancy pants however (I love running in sweatpants) I use a safety-pin to deal with the key-issues.
Yeah, that yellow thing is Pooh Bear
Even when there is a pocket in my sweats I’m still afraid my keys might get lost one way or another (it is bound to happen one day!) so to deal with this I put a safety-pin on my key(chain) and fasten the keys to my pants. This also works wonders when you don’t have pockets in your pants, in that case just wear a hoodie and keep and fasten the keys in the little pouch.
Another easy solution is using a rubber band or a scrunchy: fasten your keys in the rubber band,you can wear them in your hair or around your arm (I do recommend wearing long sleeved shirts with the latter, otherwise your keys will be all over the place).
There is also supposed to be a trick to tie your keys to your shoelaces but I don’t really know how that one works. One thing I have tried is tying my keys to those strings you sometimes have in sweat pants or hoodies. This only works when you have a pocket or pouch to keep your keys in after you’ve tied them up, it’s really annoying of you just have to leave them dangling.
Love, M.
Mixxedtape 
I have a little pouch on my shoe that fits my keys. Its not too cumbersome and it doesn’t bounce around either.
Wow your shoes are great! why don’t my shoes have something like that, here I am messing around with safety-pins while it can be so much easier 😉
Go with the pouch above instead of my methods. I once put my keys and sweatshirt in a tree by the lake front and yes, it happened. A bird picked it up the second I ran away from it. I had to chase a bird. It was too heavy for him to carry so he dropped it but it was one of my fastest sprints:D
That most have looked so funny: Mehnaz chasing the bird that tried to steel her sweater (maybe he was cold?maybe he liked the sweater?^^), now I am having second thoughts about keeping keys in sweaters though 😀