All it takes is a few tweaks to avoid injury and get the most out of your runs. Here are some tips:

Lace Up
Feet expand when you work out, so get a running shoe that allows for this (typically aim for .5 to 1 size larger). You'll also need to figure out how much you pronate (the inward roll of your foot as it strikes the ground). This will determine the type of sneaker you need. Also, be sure to replace your running shoes every 300 to 600 miles.

Stretch It Out
Warm up your muscles with a five-minute jog before stretching. Then gently stretch your calves, quads, and hamstrings, holding each for 30 seconds. Once you've loosened up your muscles, start with a slow jog, progressively increasing your speed and stride.

Energize
Never start a run hungry; you'll completely burn out. Eat something light, yet high in carbs, about an hour before you exercise (aim for about 150-200 calories). Not sure what to eat? Try a banana, a bagel with peanut butter, or an energy bar.

Stride Right
Running works every muscle in your body, so form is very important. Your arms and hands can hold a lot of tension if you don't focus on keeping them relaxed. Try pretending like you're holding a potato chip in each hand—this will prevent you from tightening up. Keep you shoulders loose and maintain an even stride (your feet should stay under your body while you run).