Once you have determined your foot type, here are other things to consider:
Try the shoes on later in the day. By then your feet will have swelled to their maximum size and will give you a more accurate fit.
In selecting the correct size of the shoe you need, be sure that there is approximately a 1/4 inch of space between the front of the shoe and your longest toe. You should get your foot measured every year to year and a half. Feet never stop changing in shape or in size. Measuring a 1/2 inch of space from the tip of your toe to the end of the shoe, as generally recommended, might be too long-- a 1/4 inch is a better indicator for marathon shoes.
Bring the type of socks you plan to wear with your new running shoes to the store with you. Socks can make a difference –cotton or man-made. Consider your foot type when using socks with your shoes. Thin socks are better to be used with wider, bigger feet and thick socks are better to be used with skinnier feet because they help take up room. Following these suggestions will help the shoe fit better.
Look at how far apart the shoe laces are as they can help determine how well the shoe fits. If the laces are pulled very tight so that they are almost touching, the shoe is too wide and will not fit correctly, especially once it breaks in. On the other hand, if the laces are so far apart that the shoe can barely be tied and kept tied, the shoe is too narrow and a wider shoe is needed. A running shoe should always fit snug on your foot to eliminate the chance of the shoe rubbing or cutting your foot and forming bad blisters.
Analyze the need to purchase running shoes based on the number of miles your old pair has on them. Do not base your need for new shoes by observing how much tread remains on the outer sole. The mid-sole of many running shoes break down between 300 to 500 miles and offer little to no protection beyond that distance.
Consider purchasing two pairs of running shoes. Switching shoes every other day increases the life expectancy of each pair. Moisture breaks down a shoe faster, so with two pairs-they are able to dry out fully. Your feet will fit differently in various shoe brands and this will lead to the forces in your feet being dispersed differently throughout your body. That means “chronic” injuries are less likely to occur. If it is determined you need a stability shoe, you should purchase two pair of the same shoes. Make sure to start the second pair a few weeks after the first pair.
Purchase a new pair of shoes that you will use during the actual event approximately four to six weeks prior to the marathon. These shoes should be the same model that works well for you during your long runs. Make sure you have sufficient time to break the new pair in prior to your race. You should look to put about 60-70 miles on these shoes prior to your marathon.
Other things to consider:
Wear your running shoes only for running. They will last much longer if you follow this important guideline. You create a different strike pattern for running compared to walking or using the gym machines.
Do not machine wash or dry your running shoes. If your shoes become dirty, hand wash them with commercial shoe care products.
When your running shoes become wet, stick bundled up newspaper inside to accelerate the drying time.
A Few More Marathon Shoe Suggestions
Neutral Running Shoes
Nike Pegasus Series
The Nike Pegasus Series provides enhanced forefoot flexibility and an improved overall ride. This shoe is made with premium Cushion foam for soft, yet responsive cushioning when you are going the distance.
Stability Running Shoes
Brooks Adrenaline Series
The Brooks Adrenaline Series features thermoplastic urethane arch shanks to help control movement occruing at the midfoot for control and support. The HPR Plus rubber outsole compound delivers ultimate abrasion resistance for long-lasting wear.