29. Bring Your Cell Phone
A marathon can take a long time, up to 4 hours or more especially if you're Oprah Winfrey. Don't let yourself get stuck out there without your phone. Whether it's to listen to your marathon playlist to get you through "the wall" at mile 22, to take a selfie at all the Cheer Zones, or to make an emergency call for help if you get lost miles from home and you're fresh out of nutrition because you already ate your Snickers bar, pez, and 9th (and final) GU, you're gonna need your phone. Think about it, you have your phone with you all the time, why leave it at home during THE BIGGEST RACE OF YOUR LIFE????!!!
Make sure you bring your phone. You can either carry it on a super reinforced armband so it won't slip off while you are pumping out 9 minute miles, or, in your anus.
More lifesaving tips are on the way!