You signed up for the Marine Corps Marathon long ago. You suffered through record summer heat as you logged mile after mile in training. Now the marathon is almost here, and your preparation is complete. Don't worry! There are still plenty of opportunities to ruin your months of hard work. Here's a top 10 list of last-minute ways to jeopardize your marathon, courtesy of Bill Corcoran, coach at Grand Prairie Regional College in Alberta, Canada, and operator of an online coaching service. Says Corcoran, "Follow these simple tips, and you can be almost assured of crashing and burning by Mile 19."

1. Cram missed training into the last few days.

This strategy worked just fine in high school, college and when you were behind at work, so why shouldn't it in a marathon?

2. Burn off that nervous energy.

Spend a few hours at the expo standing on concrete floors with thousands of fellow runners. Better yet, take the family for a sightseeing tour of the nation's capital.

3. Equate carbo-loading with gluttony.

A marathon is a long way -- you want to make sure there's plenty of fuel in the tank. So what if your all-you-can-eat attitude is giving you gas?

4. Skip breakfast race morning.

Your stomach is full enough from yesterday's all-day feast. You want to feel light when you run, don't you?

5. Wear new shoes.

If you're going to run 26.2 miles, you want your shoes to have maximum cushioning.

6. Wear new clothes.

It's important that you look good in photos from the race, so spring for the latest, greatest gear at the race expo the day before.

7. Do an extended warmup. You want to feel loose right from the start, so go for a 20- or 30-minute run beforehand. Also, arm and abdominal strength are crucial in a marathon, so make sure your warmup includes plenty of push-ups and sit-ups.

8. Start fast and bank time. You'll probably slow horribly after 20 miles anyway, so gaining a few extra minutes in the early miles will pay dividends later.

9. Avoid the early aid stations. This, too, will save you precious seconds in the early miles. Wait until you're thirsty to start drinking; by that time, the field will have thinned and aid stations will be more accessible.

10. Ignore the weather.

It's hot and humid or cold and rainy for everyone else, too, and you don't see them adjusting their race plans, so why should you? Just do it!