Even if your running shoes don't look worn out, cushioning in the midsoles and outsoles becomes compressed after 400-500 miles of running, leaving less protection for your foot upon impact with the pavement. Beginners and seasoned runners alike should analyze their foot shape and running style when choosing running shoes. While your favorite brand or color may look good on the shelf, the right fit for your foot is a runner's foremost concern.
Measure Your Shoe Size
Running puts three to five times your body weight onto your feet every time they hit the ground, so it's crucial that feet don't slip around inside shoes that are too large or jam against shoes that are too small. Measure your shoe size at home or in the store, and allow an extra thumbnail's length of space in the toe box for foot swelling or running downhill. You may want to purchase shoes a half size larger than you normally wear to accommodate for this.
Learn more on how to measure your shoe size
Determine Your Arch Shape
Examine the imprint of your wet foot on cement or a bathmat. A very narrow, curved footprint means that you have a high arch, while a wide, straight footprint indicates a low arch. Runners with high arches have relatively inflexible feet and therefore need less support from their running shoes, while flat-footed runners need maximum support for their very flexible feet.
Consider Your Environment
If your runs mostly take place on the pavement or treadmill, road running shoes offer the right amount of cushioning and stability for your repetitive strides on hard, even surfaces. Trail runners need the rugged outsoles of trail running shoes for encountering rocks, roots and mud during an off-road workout. The fortifications on trail running shoes offer extra stability and support on uneven surfaces.
Analyze Your Stride
Check the wear on the soles of your old running shoes; wear along the inside edge of your shoes indications over pronation, or too much inward roll in your stride. More wear along the outer edge of your shoes indicates supination, or outward rolling of the foot. While some pronation is natural, over pronators need extra stability and motion control in their running shoes. Supinators, on the other hand, need shoes with extra cushioning to reduce the impact on their outer foot when landing.
Test the Shoes Out
Some running stores allow customers to go for a quick run in their shoes before buying them, but if not, you should at least run in place to see how the shoes feel on your feet. Try on shoes in the afternoon or evening as feet tend to swell during the day. If you wear orthotics or insoles for support, bring those along to try with the shoes.