What do you really need in a running shoe to work out safer, longer, and better? Our guide bottom-lines it.

Yes, you can find the perfect running (or walking!) shoe

Shopping for sneakers has become a bit of an exercise in endurance. You have to sort through so many kinds—runners, walkers, trail shoes, cross-trainers, the ones with individual toes—it's hard to tell what you do and don't need.

"Shoes have gotten more sport-specific, with specialized materials, components, fabrications, and technologies to help you fine-tune performance," notes Lisa Halbower-Fenton, a footwear development and testing consultant in Boston. But does that mean you need a pair for every different sport you take on? "In general, if you do one type of activity at least twice a week, yes," says Paul Langer, DPM, a podiatrist in Minneapolis, and author of Great Feet for Life.

Each shoe helps your foot adapt to the motion of that specific sport (you go side to side in tennis, for instance, but forward and back in running). Wearing the right sneaker can help lower your chances of injury, Langer adds.

Some tips to keep in mind when you're on the hunt for athletic shoes:

Shop late in the day. Feet swell as the day goes on, reaching their largest size by nightfall.

Beware of online buys. E-shopping can be convenient, but keep in mind: Just because you bought a shoe last year doesn't mean this season's version will fit the same way. You're better off buying your athletic shoe where you can check the actual fit—or at least trying it on somewhere before discount-shopping online.

Go a bit big. Workout shoes should be a little larger than your regular shoes. You want them to fit snugly along the back two-thirds of your foot, but have a little wiggle room in your toe area. And, for a truer fit, don't forget to try on sneakers with the socks you plan to work out in.

Still not sure which activity deserves a shoe of its own? Keep reading!

Running shoes
Your body takes the brunt of up to three times your weight when you jog, so even if you run just the weekly mile or two, you need a running shoe. Built for straight-line motion rather than lateral moves, running sneaks have an inch of foam midsole to absorb shock and lessen foot fatigue; plus they're generally sturdier than, say, racing sneaks or "barefoot" shoes. Example: Nike LunarGlide+ 4 Premium ($120; nikerunning.com)

Also good for: Walking

Trail runners
If you have running shoes, these may seem like a splurge. But if you regularly run on a trail—even if it's for 10 minutes—you need a trail shoe, says Hillary Brenner, DPM, a podiatrist in New York City. Why? The nubs on its thick outsole dig into dirt—so you avoid taking a spill—and a guard under the midsole protects feet from debris. Example: Columbia Ravenous Lite Flash ($85; columbia.com)

Also good for: Hiking (but only in a pinch)

Tennis shoes
If you ever step on a court, these are a must. Made to handle the rigors of the game and an abrasive court, they have rubber soles designed to prevent the kind of sliding and stumbling that's common in tennis because of quick lateral moves and sudden starts and stops. Avoid running or walking in your tennies (not enough cushioning or back-to-front stability). Example: Asics Gel-Solution Speed ($130; asicsamerica.com)

Also good for: Racquetball, volleyball, and other court sports

Everyday walkers
If you walk for exercise, you need walking (or running) shoes. Both have a flexible forefoot to accommodate the way you naturally roll through the foot. And although walking shoes are considered a scaled-down version of running shoes, runners should steer clear (less shock absorption). Example: New Balance Superlight/Superfresh 895 ($85; newbalance.com)

Only good for: Walking

Race runners
Built for speed, a racing shoe is made of lighter-weight materials than a standard running shoe. "The less effort it takes to propel the foot, the faster you'll go," Langer explains. But unless you regularly enter 10Ks, you don't need these. Weekend warriors who run the occasional race can stick with their regular running shoes, Brenner says. Example: Puma Faas 350 S ($85; puma.com)

Also good for: Short (under 20-minute) jogs or strolls

If your workouts consist of weight-training or aerobics classes, this is your go-to shoe. Flexible soles allow you to move in any direction without twisting an ankle. And although experts suggest wearing a running shoe anytime you run, it's safe to wear cross-trainers to warm up on the treadmill, Halbower-Fenton says. Example: Reebok R Crossfit Nano U-Form ($120; reebok.com)

Also good for: Playing with the kids outside or doing squats at the gym

Dance sneakers
These are similar to cross-trainers—they're low to the ground and flexible—so you can use them interchangeably. But if you dance daily (if you're big into Zumba, for instance), look for dance sneaks, which come up to the ankle for added support. Example: Ryka Downbeat ($80; ryka.com)

Also good for: Weight-training and aerobics classes

Barefoot shoes
Popular for running, speed-walking, or cross-training, these minimalist shoes offer some protection against abrasions, thanks to a thin rubber lining along the bottom. Try them if you have no foot issues and a normal arch. Example: Vibram SeeYa LS ($100; vibramfivefingers.com)

[ pagebreak ]Here's a guide to some of the important terms to know when it comes to shoe shopping:

Heel collar: A foam-rubber cushion that pads the ankle and rear foot, and keeps your foot from slipping out.

Heel counter: Stiff back portion, typically made of plastic, that gives structure to the shoe's upper.

Outsole: Usually made of carbon rubber (the same kind used for tires), which is especially resistant to friction and good for traction.

Upper: Supports and keeps your foot in place with the help of shoelaces and/or Velcro straps.

Insole: Also known as the sock liner, it improves fit, stabilizes the arch, and just plain feels good to your foot.

Midsole: A layer of foam material that absorbs shock and evenly distributes pressure.