With its crisp alpine air, rugged terrain, and unique physical challenges, the great outdoors offers an excellent venue for athletes. Whatever your level of fitness, a hike in the woods may be just the change of pace you need. To fully enjoy day hiking follow these simple steps.

Step 1: Choose an Appropriate Hike

"Choose a hike based on your cardiovascular fitness," recommends Greg Auch, back country education coordinator for the Appalachian Mountain Club. "If you've hiked before, consider the nature of that hike and how you felt. Then consult a trail guide." With detailed descriptions of trails, including distance, altitude, difficulty, and estimated time to complete the hike, trail guides are the best resources for hiking information.

"Over moderate terrain," explains Auch, "the average person can cover about two miles per hour. In addition, every 1,000 feet of elevation equals another hour of walking time. Keep this in mind as you decide how long, how far, and how high you'd like to hike."

If you plan to climb the higher elevations in the west, where trails often begin at 8,000 feet, factor in extra time to adjust to the altitude. "You can push yourself to reach higher altitudes, but it is important to give your body a chance to recover," advises Scott Reid, education coordinator for the outdoor ethics organization, Leave No Trace. "Sleeping at a lower elevation from which you hike is one good way."

Step 2: Fill Your Pack

For any alpine excursion, carry a daypack—a lightweight backpack—filled with these essentials:

Trail guide, compass, and map —Learn how to use them before heading out; some outdoor stores offer short courses on using maps and compasses.

Water —"Ideally, you should drink a quart of water per hour, especially at high elevations," says Reid. "This amount of water is pretty heavy, so carry two quarts plus water purification supplies, such as a filter or iodine tablets, then you can refill at streams along the way."

Food —Choose high-energy goodies that won't disintegrate on the trail: energy bars, granola, bagels, pita bread, candy bars, oranges, apples, and raisins.

Extra clothing —Weather in the mountains is very unpredictable; be ready for anything—cold, heat, wind, rain, or snow.

First aid kit —In a waterproof container, stash some antibiotic ointment, band aids, moleskin, and an ace bandage.

Flashlight, waterproof matches —In case sunset sneaks up on you, you'll be prepared.

Sunscreen —The thinner air at high elevations offers less protection from the sun's rays, so wear sunscreen year round.

Raingear —Hikers in the west can expect a daily afternoon thundershower in the summer, but all hikers should be prepared.

Step 3: Dress Appropriately

"In the mountains, sturdy, waterproof hiking boots are a must," instructs Auch. The "must-have" list also includes two pairs of socks "a lightweight liner (polypropylene or polyester) and a cushioning, wool sock" and warm, waterproof gloves, as well as a hat in colder weather.

Mountain weather is generally cooler, cloudier, and windier than the climate in lowland areas, making improper dressing a serious health risk. Layering helps you stay cool when active and warm when at rest; just add and remove clothes as needed.

Inner layer —Wear close-fitting long underwear made from polypropylene or silk, which should dry quickly and pull perspiration away from your skin.

Middle layer —This layer should be light-weight and breathable—flannel, wool, down, or fleece. You may want extra middle layers in colder climates.

Outside layer —To block wind and rain, try Supplex (wind-resistant) or Gore-Tex (great for rain and snow).

Avoid wearing cotton; it will hold moisture on your body and interfere with temperature regulation.

Step 4: Stay on Track

Now that you're ready to head off into the wilderness, be sure to stay on the trail. This is easy to do if you follow the blazes, which are two-inch by six-inch marks painted on trees and rocks along the trails. Once you get above the tree line, look for small piles of rocks called cairns to stay on track. And always have your trail map handy.

Whenever possible, hike with other people. Allow the slowest person in your group to set the pace, especially if kids have come along, and take frequent breaks for water, snacks, and rest.

Step 5: Stay Healthy

Hiking requires the same cardiovascular fitness that running , cycling, and other endurance sports demand, but relies on different muscle groups, which can leave you aching in unfamiliar places.

Conditioning —"To condition your muscles for hiking, do a few short training walks carrying your day pack for two to three miles at a time, and some extra stretching ," recommends Auch. He's found that hikers who hit the trail with a reasonable degree of strength and endurance are less likely to experience the sprains and strains common among novice hikers.

Poles —Trekking poles (or ski poles) provide extra stability on challenging terrain and take some of the strain off ankles, knees, and hips. To keep your feet comfortable, be aware of sensitive areas and treat them with moleskin before they progress into painful blisters, and break in new hiking boots before taking them on a serious trek.

Altitude sickness —"Accidents can easily occur at high altitudes," explains Reid. "As you climb, the air becomes thinner and drier, making breathing more difficult and increasing the risk of dehydration." This can leave you weak and light-headed, and can severely affect your ability to hike distances. If you are new to hiking at high altitudes, get plenty of rest, hike slowly, and give your body a chance to adjust.

Dehydration —To avoid the headache, fatigue, irritability, and dizziness that accompanies dehydration, drink plenty of water before, during, and after your hike.

Step 6: Be Alert for Critters

Consult your trail guide to learn which animals you may meet along your trek, and check with the local ranger to find out if there are any special rules you need to follow.

Snakes —If you plan to hike in desert areas, avoid rattlesnakes and their ilk. Hiking boots which go above the ankle are adviseable.

Large mammals —In woody areas, you may encounter bears, moose, or deer. "When hiking through bear country, make some noise or attach a bell to your backpack so they'll hear you coming; the last thing you want to do is surprise a bear in the woods," advises Reid. "If you come upon any animal, remember that you are in their home. Try not to spook them, let them move at their own pace, and never try to feed or follow a wild animal."

Insects —Bring along bug spray and insect repellent, especially in early spring in the northeast when black flies and mosquitoes are abundant. And always stay on the marked trail to avoid poison ivy and deer ticks, which can cause Lyme disease .

Happy Trails

By following these steps, you'll be prepared to enjoy your time in the woods. To help preserve the woods for others, follow the rules of low-impact hiking: leave only footprints, take only memories, and kill only time.