Avoid these common race day mistakes during your marathon.

Not hydrating enough. Runners can neglect drinking enough amidst the excitement and when temperatures are cool. While you might not perspire as heavily as during your training, you still lose more fluid through your breath than you think. For best results, stop to drink as frequently and at least as much as during your long training runs. Choose sport drink with electrolytes over water when possible, provided you’ve tried it before. Learn about hypertremia, which is water intoxication and can lead to serious illness for runners.

Starting the race too fast. The most effective way to run a marathon is even pace or to run negative splits, which means running the second half of the race faster than the first half. Running fast early miles only gets you into trouble in the end.

Believing others are your competition. Your competition is you — not other runners. Don’t obsess on finishing ahead of other runners who look less fit or athletic than you. You know nothing about them. Pay attention to your running, and focus strictly on the details you can control. In a marathon, it’s you against the distance.

Abandoning your race plan. Unexpected realities and excitement can cause lapse in judgment at the last minute. Unless you have a calamity, stick to your race plan. Don’t move up to get a better starting position, join a faster pace group, alter your clothing plan, pass up water stations or try to keep up with a runner whom you befriend. 

Slowing down at the first sign of struggle. When you face the inclination to slow down, replace it with relaxed running. Relax your face, lower your shoulders and shake out your arms. Relaxing involves new muscles and can renew your pace and bolster your confidence in a very short stretch.

Letting the crowd drain your energy. A marathon offers an outpouring of enthusiasm for both the field of runners and the spectators. Plus news crews, bands, PA announcers and signage can drain your energy and distract your attention from the job you have to do. Enjoy the color and excitement, but don’t let emotion and sensory overload zap your focus and energy.

Running overdressed. Cool temperatures a few hours before race time can be misleading. The temperature will generally rise while you’re running for 3, 4, or more hours, and you could be hot by mile 15. The human body running a marathon is a furnace, so plan to dress as lightly as possible and to discard layers as you can. Rule of thumb is wear less than you think you’ll need; shorts and singlet are adequate at 45 degrees or warmer. Wear caps, gloves, and long-sleeve shirts that can be discarded. 

Going unlubricated. For longer races, it is especially important to lubricate any vulnerable areas where there could be friction against the skin (feet, toes, thighs, underarms, nipples, bra strap areas, etc.). Don’t use a petroleum product like Vaseline. Instead use a special product like Body Glide to prevent chafing or blistering. 

Being unprepared for post race. Plan for the challenges after the race, including re-uniting with family and friends, and having a change of dry, warm clothes, including socks, shorts, and shirt, and even flip flops to ease the pressure on swollen feet. Pack a damp towel in your gear bag to wipe of the sweat and salt from your face and body.