Science 10 Question Sheet: Running with Sneaker Science Answer all questions neatly in complete sentences on loose-leaf. Use blue or black ink or write with a pencil!

Everyone's feet are different, though there are some general categories based on the shape of the arch. I have slightly flat feet, which makes my legs roll inward and throws my stride off kilter. I used to have severe knee pain as a result, until I started wearing stable shoes with lots of support.

Each shoe and piece of clothing is designed and tested to meet specific needs, Valiant says.

Marathon runners want lightweight footwear with plenty of cushioning, for example. Racing shoes for shorter distances often sacrifice cushioning for flexibility. Basketball shoes need to be sturdy enough to deal with lots of twisting and jumping.

Moreover, the best combination of shoe length and width varies from men to women to kids, and among people from different ethnic backgrounds.

With so many choices, it's important to make sure you don't get sucked in by the latest styles, Kinley says. "Just because it's fancier looking or has cool colors or costs a lot," he says, "doesn't mean it's a better shoe to have."

Hoping to avoid some of the pain of my first marathon, which I had run months before in Minnesota, I went looking for tips at the Nike store in Boston the day before this year's race. There, I met Mark Riley, business director for men's running footwear. He had traveled from Nike headquarters to run his 12th Boston marathon.

Near the finish line of the Boston marathon.

Hans Kieserman

"Don't start out too fast," Mark warned me over and over. The biggest hills come late in the race, he said, and you want to make sure you have enough energy left to charge up the slopes. "Trust your training," he added. "You'll do great."