Consider your exercise regimen. Depending on your workout, shoes designed for walking, running, tennis, cross training or another specialty will provide the best support for your feet.

Shop when you normally exercise. Feet actually get bigger throughout the day, sometimes swelling up as much as a half-size by nighttime. So don't shop first thing in the morning if you often work out in the evening.

Try them on. Never grab a pair of exercise shoes based solely on the size footwear you normally buy. Bring the type of socks you'd wear to work out and go for a spin through the store.

Focus on fit. You should be able to fan your toes out comfortably, with about a half-inch of space between them and the front of the shoe. The back should fit snugly against your heel and not flop up and down. If your feet are different sizes, buy based on the larger one.

Don't look to "break in" shoes. While shoes may get more flexible with use, they should be comfortable the first time you wear them.

Talk to an expert. Shoe salesmen and personal trainers can study your stride and the shape of your feet and recommend the best shoes to guard against injuries.

Replace worn shoes regularly. Many trainers recommend switching footwear every three to five months, if possible, to maintain proper cushioning and support.

One tip: if you have to tie your shoes very tightly to feel a good amount of support, they may be ready to go.