NCAA runner turned high school coach Hillary Kigar has an answer for all things training–including the best safety and injury-prevention solutions for carrying phones and other devices while running.
I carry my phone in my hand during runs—am I throwing off my balance or messing up my stride?
Everyone has different running form; while you might run pretty efficiently with your phone, most likely it does impact your stride. Over the course of a longer run, your running efficiency will lessen, meaning that it will take more energy, as you are off balance and not running as smoothly as you could be. Visit your local running store or look online to check out the available running armbands and belts. These will hold your phone, allowing you to run with free hands. Armbands are helpful as you still have easy access to your phone to change the song or check your GPS app. Running belts are a great option if you want to store your phone out of the way. Belts usually adjust in size, fitting around your waist snugly, with the option to wear the pouch in the front or the back.