Can you suggest a gift for a Navy man who is retiring and who likes to run?

I’m invited to a retirement party. It’s the husband of a friend of mine, I have never met him. He is retiring from the Navy and I asked my friend what hobby or interests her husband has so I can get him a small gift and she told me he is a runner.

I don’t run, so I am looking for some ideas. It can be anything from a token gift topping out at $50. They don’t expect anything of course, but I’d like to bring something.

Aside from running, if you have a good suggestion for Naval retirement I’ll be glad to hear that also. I don’t know what he did for the Navy, so I can’t give any info about that.

Thanks.