Thanks everyone. Taking my phone is because I often listen to podcasts whilst running and I’ve not quite got to a fancy watch with Spotify yet. 90% of the time I take little other than phone and keys so I use a cheap elastic belt to carry them.
But if I’m going out for longer and the weather is changeable then it’s more pleasant to be able to stash a windproof somewhere or take off gloves rather than just cope. Equally I often run and stop now and again so being able to take a warm layer can make it more pleasant.
I’ve bought one of the OMM ones so will see how I get on.