There are a few items that I just wouldn't be able to run without these days. Just practical, things. Personally I don't run with music (or hardly, hardly ever, maybe I have once this year I think), it is partly a safety thing and also partly that running is my quiet time, my thinking time. Or, if I am doing a harder session then I just need to be in the moment and concentrating. I'm lucky, I have never felt the need for distractions when I run, I have just always loved it and am happy to be in the moment when I run.
The first item is my trusted shock absorber bra. Ladies, if you haven't yet had a sports bra fitting from your local Sweatshop trained sports bra fitter, prepare to be enlightened. Wearing a proper sports bra with a proper fit WILL change your running. It improves your posture and you don't feel so self conscious, it can also reduce breast pain from running too.
http://www.shockabsorber.co.uk/en/the-science/(other brands are good too, I just love this one).
My next essential piece of kit are my trainers, now, I won't post a picture of all the running footwear I own (I have become a typical girl, shoe queen when it comes to sports shoes), I do work one day a week for Sweatshop (running specialist store) and I do love having just the right type of shoe for a specific distance, terrain etc. My main pairs that I wear the most for the majority of my miles are my Brooks Pure Cadence for road miles (see right) and my Adidas Kanadia for my off road runs (below). Having the right type of shoe for you is absolutely essential. If you have never had a running specialist have a look at your gait (the way you land and the way your foot and ankle moves during running) analysed then I recommend you take the time and visit a running specialist store (such as Sweatshop, yes I am biased!) and get it done. http://www.sweatshop.co.uk/stores This will ensure the trainer is the right fit (no more black toenails people) and that the shoe has the correct cushioning and structure your own running style.
Next up is something that I only started wearing about a year an a half ago, it is my Cramalert id band. This has become something that I simply won't run without (or bike, or open water swim etc). I don't always carry a phone, and up till about 18 months ago I would have had nothing on me at all to inform anyone of who I was or where I live or who my next of kin were. Wearing an id band (there are many different types out there) won't prevent something happening to you (as I found out last year when I fell down a rabbit hole and sprained my ankle badly), but if something unfortunate did occur it would allow the emergency services to contact family and find out relevant medical history etc. I wouldn't do without it. http://www.cramalert.co.uk/
Those are my bits of kit that come with me on every run. Everything else (clothing, socks etc) are season/weather/race dependant really. I do use a Garmin 410, but don't wear it all the time and would never personally race with it. I also use a Salomon hydration pack for longer training or to carry essentials during fell runs. My other favourites are Vitacoco for hydration, or sometimes Nuun tablets, Nakd bars or Torq gels for longer training and of course, sunscreen (for wearing).
My only other essential is my regular sports massage and occasional trip to my physiotherapist to keep my niggles at bay and keep me moving well. This is really something I would not be without in my running, using treatment as recovery/maintenance and injury prevention is, in my opinion key to a long and happy running life with little or no injury enforced brakes in continuity. But, again, I am biased, I am a sports massage therapist specialising in sport injury! www.hazelclarksportsmassage.co.uk