Cold temperatures and short days can challenge your routine if you walk, run, or cycle outdoors. But with a bit of caution, common sense, and the following tips, you can keep at it all season long.

Embrace the dark -- safely. Wear reflective gear or flashing lights so you're clearly visible to drivers, and stick to familiar terrain. "Go where you know every crack and bump in the sidewalk," says Janet Hamilton, M.S., exercise physiologist and author of Running Strong and Injury-Free. Also, avoid using headphones, since you need to be aware of your surroundings at all times.

Reschedule. If you dislike exercising outside in the dark, try a lunchtime excursion, suggests Hamilton.

Wear layers. Wear wicking fabrics next to your skin, another layer for warmth, and -- if needed -- a third layer that's wind- and waterproof. Top layers should be easy to remove.

Get the right gear. Keep your fingers covered. Although gloves suffice for most people, mittens are warmer. And wear a hat when it's below 40 degrees. If icy puddles are a possibility, wear waterproof shoes, advises Doug McKeag, M.D., director of the Center for Sports Medicine at Indiana University. "There are plenty of great, high-tech wicking socks out there, but none of them can combat sopping wet shoes."

Breathe right. In extremely cold conditions, you should be aware of your breathing. "Try to breathe through your nose," McKeag advises. "It helps warm the air before it gets to your lungs."

Psych yourself up. Tell yourself you only have to go a half-mile or stay outside for 10 minutes. "Nine times out of 10," Hamilton believes, "you'll just keep going."

Recruit a friend. Exercising with a partner in very cold or otherwise severe weather is always a good idea from a safety perspective, McKeag says.

Don't stray too far from home. If you're a long-distance runner or cyclist, repeat a shorter circuit. "Conditions can change, and you can get into trouble if you're too far out," McKeag says.