IN THE STORE When comparing models, fret not over weight. A few ounces make scant difference out on the trail. Innovative fabrics, such as antimicrobial linings and bi-component knits for wicking, spell more comfortable, thus happier, feet.
IN THE FIELD Trail runners are built sturdier than street shoes, but they're hardly indestructible. The midsole cushioning will surrender faster than the French army if you use them for backpackingor barhopping. Save them for serious weekend mileage and you should get as much as a year (or a single Western States 100) from a pair. Your twisting ankles will tell you when it's time to hang them up. A firm thumb press where your heel goes will, too. The foam should feel soft, not packed-in hard. On the trail, loosen the laces as your feet swellbut crank them down for steep sections where control is vital.
IN THE FUTURE Tomorrow's shoes will custom-mold themselves to your feet. Reebok's Pump 2.0 road shoe points in that direction with its expandable air chambers; tomorrow's models may employ high-density memory foam or inserts to "cure" around your feet.