Training for Hiking

I used to use treadmills a great deal and when the weather warmed up and I ventured outside, I always found that my calves hadn't gotten enough of a workout from the treadmill.
That said, it is better than nothing.
You might also try splitting time between a treadmill at a high rate and a stair climber at a high incline.
Good Luck.

go hiking, a lot. get a camelbak and good shoes.

Stairs! I work in at 38 fl building so it's easier for me to get a good workout on stairs. Just climb and get further each time before you take a break. That's how I train for the new england 4000 footers and let me tell you, my calves can kill by the falltime!

My advise would be to use your tredmill during the week, get up early and get your workout in before you leave for work. Here is a good one. I would advise doing this uphill routine 2 days a week and then just walking for an hour at 1% incline on the other days. Then going for a long 1:30-2 hour hike on the weekends and building from there. Good luck!

http://www.fitsugar.com/Mountain-Hike-Treadmill-Workout-295661

stairs. i challenge you to go up and down just one flight of stairs 50 times and time yourself. move quickly and keep knocking time off. it takes approximately 1714 steps to go up 1000 ft of elevation. also, do you have any hills or better yet woods near you. we do right out our back door and my wife and kids go hiking through it in all weather conditions as they are preparing for a trip to Colorado on a youth leadership trip. and most of all, get out as much as you can! anything is better than nothing

What kind of hiking are we talking about? What kind of terrain? What kind of mileage? How long? What is the difficulty level of the trail(s)?

Training for a casual day hike on an easy to moderate trail is going to be different than training for a more intense day hike on a difficult to expert trail is going to be different than training for multi-day backpacking excursions.

If your're going to be doing some serious hiking, you need to hike...there really is no substitution. If it were me, I'd hit the trail a couple times per week during the work week for some shorter duration hikes done at a faster pace with a loaded pack...then make sure I was getting progressively longer hikes in on the weekends. I'd throw in quite a bit of general walking as well with my pack on as well as some stairs and what not.

But again, this really depends on the nature of the hikes you will be doing. I'm at a fitness level where I could pretty much handle any kind of day hike without much issue...a multi-day excursion and/or very difficult trails would require me to do some actual training I think.

Treadmill incline programs with a weighted pack.

Incline treadmill, weighted lunges, weighted squats, trail running, hill running.

There is actually a cardio machine called a summit trainer. I haven't used one so I can't attest to its usefulness but if your gym has one, it's worth a try.

Lower body strength exercises are what I have found most useful.

I would also add that there are any number of other considerations to think about when hiking. One of my favorite hikes here in the Albuquerque metro is the La Luz trail which goes from the base of the Sandia Mountains in the foothills of Albuquerque to the Sandia Crest. It is an awesome hike, but a difficult one in that it climbs 3,200 ft in 7.2 miles to an elevation of 10,678 ft above sea level. Many novice hikers are unprepared for the fact that it can be sunny and 70* at the base and well below freezing with snow at the top. Many hikers are also unprepared in RE to water and food...numerous hikers are stranded on this trail annually and require search and rescue operations due to just being unprepared and ignorant of what they're getting into.

ETA: Just be aware that there are most likely going to be other things to consider beyond your fitness.

What kind of hiking are we talking about? What kind of terrain? What kind of mileage? How long? What is the difficulty level of the trail(s)?

Training for a casual day hike on an easy to moderate trail is going to be different than training for a more intense day hike on a difficult to expert trail is going to be different than training for multi-day backpacking excursions.

These are very important questions.

I haven't done any multi-day backpacking (yet!), but I can let you know what I do to improve my performance on more intense day hikes:

1) Running on a flat trail. My biggest weakness when hiking with others who are quite fit is I can't keep up with the cardio of a high elevation gain trail (e.g., 1000 ft over a mile). I've found that if I can stick with running, it improves my ability to knock out a high elevation gain trail more quickly and I'm less likely to be the one holding the group back.

2) Short hikes during the week. I'm fortunate to live in an area where there are large foothills on the edge of town and during the week I can take a short hike that covers something like 3 miles and a few hundred feet of elevation gain in less than 2 hours including travel time to the trailhead.

3) Weight training. Stronger legs and a stronger core improve performance for me.

4) Increasingly difficult weekend hikes. I plan on doing a 17 mile hike this September, so during the summer I will be taking increasingly longer hikes and spending more time above 10,000 ft to prep for that. I'd also like to finally do a 14er, so I will practice by slowly increasing the mileage and elevation gain of my hikes leading up to the major hike. I do this every year: the first non-snowshoeing excursion into the mountains of the season is usually a pretty short trail without too much elevation gain.

I usually only carry a few liters of water and some snacks on my hikes, so I haven't found the need to train with a pack. However, if you're looking for something like a multi-day backpacking excursion training with the pack would probably help. It might also help if you aren't used to carrying a pack and in the past find it increases the difficulty of your hiking.

Adding a link. This is for people training to go Philmont Scout Ranch in New Mexico. Many of us going there don't have the benefit of training at altitude.

http://www.scouting.org/Philmont/Camping/Hikers/physical.aspx

The other posters are absolutely right that other endurance training will help but I'd suggest building up your tolerance to inclines as well if you can. Start by on your next day off doing the steepest route you can manage at the moment, repeat for two or three weeks then find another one that is a bit steeper and do the same thing. Rinse and repeat till you reach your goal or you need to buy a rope and start learning rock climbing moves.

You can do the same with distance, don't worry too much if it is only once a week so long as you are keeping your general fitness up with other exercises you can increase your hiking ability with this it just might take a bit longer.