What you wear can make the difference between an enjoyable and a frustrating marathon experience.

Every runner should have a checklist that coordinates your running gear to the temperature outside. Layering allows you to adjust to the conditions throughout the run. Remember that a marathon can last for a number of hours, during which the temperature may change dramatically. The temperature and conditions for running New York can swing wildly throughout the day, with many runners finishing in the late afternoon and into the early evening. So take a little extra precaution and spend a bit more time on preparation.

The following is a chart that I created based on my experiences running during the past four years in New York. This list was very different when I lived on the West Coast; in fact, I don't think I even owned some of the items below. Everyone's list will be a little different based on how hot or cold each of us gets, so feel free to make your own.

DRY CONDITIONS

* Temp>60 -- shorts & singlet, cap.
* 55<60 -- shorts & short-sleeved shirt or singlet, cap.
* 50<55 -- shorts & short-sleeved shirt and shell vest or long-sleeved shirt, cap, possibly lightweight gloves.
* 45<50 -- shorts, long-sleeved shirt or short-sleeved shirt with a shell vest, cap or fleece hat, gloves, possibly something covering neck.
* 40<45-- shorts with wind pants, long-sleeved shirt and shell vest, Coolmax scarf or buff to cover neck mouth and nose, use lip balm, cap or fleece hat, glove.
* 35<40 -- lightweight running tights or shorts with wind pants, long-sleeved shirt and shell vest or light-weight jacket, Coolmax scarf or buff to cover neck mouth, and nose, fleece hat, light-weight gloves and lip balm. Create barrier between cold air and breathing pathways to warm up inspired air.
* 20<35 -- Heavier running tights, short or long-sleeved shirt with jacket, cover neck, mouth and nose (Coolmax scarf, buff, or baklava), fleece hat, warmer gloves, cover all exposed skin.
* Temp0<20 -- Same as above, but heavier long-sleeved shirt, focus on warming the air before inhaling, and possibly 2 pairs of gloves.
* Temp<0 NYRR Frostbite 10-miler in January: Stay in car until the last moment, get out and run when the gun goes off, forget waiting around for medals and drive home. Get under covers and stretch. No one recognizes anyone in these temperatures anyway.

WET CONDITIONS

Move more quickly to a shell vest or light-weight jacket. Consider temporarily wearing a heavy-duty construction trash bag (obtained at a hardware store; not the kind you get at a grocery store) over the clothes identified above, whenever you will be in the rain for extended periods of time. Duct tape small trash bags over your shoes while waiting around or wear short gators in torrential conditions. Avoid puddles until it becomes ridiculous to do so.

Sunscreen and sunglasses should always be worn except in rain to protect the obvious. Put your sunglasses on your cap if it begins to get overcast or dark.

The following articles on cold weather running have been excerpted from a Nike newsletter for your information.

Cold Weather Running

Cool weather allows you to run fast and recover even faster. But when temperatures drop below 32 degrees Fahrenheit, speed work can become dangerous. So as winter approaches, make sure to practice cold weather training safety. Don't attempt short, fast speed workouts -- especially fast intervals -- when it is extremely cold. Cold weather causes your muscles, ligaments, and tendons to remain very tight and unable to loosen up adequately, resulting in a lack of efficiency in your motion and possible injury. Do light, race pace runs to keep moving and warm.

Here are some other tips on cold weather training:

* Take it in stride. If you try to run very hard, your lungs will feel scorched and your throat sore and raspy.
* Cooling occurs very quickly between sessions. Be prepared with more clothing between workouts, and towel off to keep from getting cold and wet.
* Adjust your time goals. You are forced to go more slowly since your body can't go all out in the cold. Plus, extra clothing may slow your pace a bit.
* The key is to keep moving and slow the pace. Don't overdress or you'll overheat, even in the coldest weather. Carry a hat, gloves, and windbreaker so you can adjust to the conditions on the fly.
* Don't under dress either. Wind and moisture resistant hats are very important, since the head's blood supply causes lots of heat loss. Sweaty cotton is a very poor insulator, so choose synthetic mix fabrics that wick moisture and maintain insulating properties even when wet.
* Take extra time to warm up. Jog three or four miles before doing anything hard, and then conservatively ease into harder workouts.
* As soon as you're finished, take off your wet shirt and put on a dry one and add extra clothing if needed - just like you would in a cold weather race. Keep jogging to prevent tightening up, and head for a warm place.
* As soon as possible, take a warm bath or shower, but not until your body has fully recovered from the workout and your heart rate is back to its normal level.
* A strong wind can ruin workouts. If it's at your back, it can push you along faster. If it's in your face, it slows you down and you fatigue more quickly. When the wind is strong just run at your intended effort level and forget time goals.
* In cold, steady rain, stick to a consistent, brisk strength run at a moderate pace.
* Ice and snow can be fun to run in, but risky. Never attempt to run hard on slippery conditions. Adjust your workout by running a slower, steady pace so you can be sure of a strong foot plant.
* Don't ignore your own common sense - it may send you looking for an indoor track, indoor bike, treadmill, or pool.

How Weather Affects Your Shoes

You choose your running shoes with care. You know to try on shoes late in the day when your feet are largest. You firmly flex the shoes in your hands, checking for stability in all directions. You try the shoes on around the store, on the treadmill, maybe even running up and down some steps. When you've finished your stringent process you make a thoughtful choice.

But how your shoes felt in the store and how they feel in extreme weather are not always the same. In the middle of winter and in the middle of summer, motion control and cushioning change, according to a collaboration between Hiroshi Kinoshita, Ph.D. at the University of Osaka in Japan, and Barry Bates, Ph.D., at the University of Oregon in Eugene.

Running shoes are made mostly from synthetic materials. And the mechanical properties of many synthetic materials are very temperature sensitive. In this study, running shoes were worn by male runners, who warmed up for ten minutes then ran for 40 minutes on asphalt roads in different temperatures throughout a year. The midsole temperatures of the shoes were measured throughout the runs. Then the shoes were taken to a laboratory, and their mechanical properties were measured at the temperatures reached during the outdoor runs.

The testing showed that the shoes softened enough to lose significant motion control in the summer temperatures, and stiffened enough to lose significant cushioning in the winter temperatures, compared to their properties at normal room temperatures.

The authors of the report suggest it may be better to buy firmer shoes for summer and softer shoes for winter. They also concluded the possibility of injuries in summer and winter may be higher than in spring and fall, when shoes behave more like their designers intended.