SocksIt sounds cheesy, but at close to $10 a pair, running socks are one of my most appreciated gift item. Sizing is forgiving, just make sure you get socks that are made of synthetic material (i.e. no cotton!)
Energy Gels/ChewsThere are tons of these on the market and most runners like to have the opportunity to try new fueling options during training. For just a few bucks you can stuff a stocking to the brim with these!
Hydration MixesIn the same vein as the energy gels, hydration mixes can be bought in powder form, ready to be mixed by your runner recipient. These come in packages, tubes, and tubs, and in tons of flavors other than lemon-lime.
Gloves/Arm SleevesEven midsummer races start at the crack of dawn and most runners like to have a little something to fend off the cold while waiting for the gun to go off. Even cheap "painters gloves" which can be discarded when the race starts are great!
Race EntryWhat runner would not want a free race to train for? Especially one in the off-season to work off some of those holiday calories! 5k is probably a good distance, signing your runner up for a marathon may not be appreciated as much as you might think.
MP3 playerThis is a bit of a hotly debated topic in the running community, but even runners who are dead-set against music while running will reach for one for treadmill workouts. This is the most expensive item on the list, but the small ones can be purchased for under $100.
Magazine SubscriptionWhat do runners like doing nearly as much as running? Reading about running! Plus it's the gift that keeps giving for a whole year!
Granola Bars/SnacksApart from running and reading about running, eating is the next most popular activity. Energy bars, granola, pretzels, trail mix, it's all good and it's all cheap!
Massage Gift CertificateMost runners need massage as a recovery tool, but most can't justify the cost.
Foam RollerThis is just what it sounds like, a foam cylinder that can be rolled over sore muscles as an at home massage tool. At around $15 this is probably the best value for the money on the list. If your runner does not have one already, rest assured, they want one!
I hope this list helps some shoppers out there. Behind every great athlete is a great athletic supporter! (Sorry I couldn't resist)