I know, for most this is stating the obvious and as runners we hear it all the time. It doesn't necessarily mean we listen to the advice though. I've tried more than my share of 'new' stuff on race day. Most of it was clothing related.
When I ran my one and only Boston Marathon in 2005 I decided to wear a new pair of socks. Not just store-bought new but new like I never wore this type of sock ever in the history of the world new. I had trained through a pretty cold winter so a 70 degree sunny day on Marathon Monday was not what I was hoping for. The socks were some sort of double lined Coolmax sock. The double liner (and my foot) rubbed together like a couple of sticks trying to start a fire and by mile 7 I had to stop and take off my shoe and sock to check the damage. I already had a huge blister on my arch. I'll just say it was a painful 19 miles...I almost learned my lesson.
As I prepare for my longest (time and distance wise) event I've ever attempted, the brutally insane Jay Mountain Trail Marathon, the one thing I do know is don't try anything new. So I practiced and experimented in the relative safety of my local trails. I've tried the socks I want to wear, the shoes I want to wear and the clothing. I've tried the hydration systems as well (hand held water bottle, fanny pack and Camel pack). I've tried band aids and blister control patches and bug sprays. I've soaked my shoes and socks in the pool before my runs and then ran in every puddle, brook or swamp I could find along the trails to keep my feet wet. I must admit, this was a smart thing to do. I learned a lot about what might work and what clearly doesn't. I can't wait until Saturday!