Should I train for the PCT?
YES. I'm sorry, but this is a stupid question. Of course you should train for a multi-month physically demanding hike. The more physically fit you are, the easier the trail will feel. And the happier you will be.
There are many challenges to completing a thru hike. Getting yourself into the best shape you can prior to attempting the hike will not only increase your chances of success, but will likely increase your enjoyment of your time spent on trail. Thru hiking is hard. It hurts. Everyday. You will go to bed aching and probably wake up still aching. Chances are you will often think things like, "I don't know if I can do this. I just never stop hurting."
You will likely be contending with environments and weather conditions to which you are not highly accustomed. You will encounter critters you may not know how best to deal with. You will undoubtedly begin your hike with more weight in your pack than needed. And no matter how much you train, you will likely have some adaptation period physically. Any one of these things can negatively impact your hike... severely. By being in as good of physical shape as possible prior to getting on the trail, you effectively reduce or eliminate a very real challenge, allowing you to focus on solving the others. Not to mention, getting healthy and fit has literally no downside.
Still not convinced? I figured as much, and have anticipated some of your questions below:
“I talked to someone who finished the trail and did no training prior”
Sure, I met several people who rolled off the couch and onto the trail and did quite well. They're lucky. Sure, you may be a fatty and are eager for the hike to begin so you can lose weight. Why wait though? We spend hours agonizing over grams — grams — of gear in our packs, why not spend some time reducing the pounds on your body? Your knees, ankles, and particularly the bottoms of your feet will thank you immensely.
“But finding the time to exercise is hard”
Yep. You're right. It is very hard to be successful at modern life and be fit and in shape. What are your priorities? Can you live without watching the latest episode of GOT? If not, you may need to replace your couch with a treadmill. The good news is that it really doesn't take that much to push the needle in a favorable direction.
Getting out for walks with a weighted pack every other day, especially if there is stair climbing involved is a great way to strengthen up for the hike. You don't need to have a great hilly hiking trail in your local woods. (A common excuse I heard for not training in advance). I trained for my hike almost exclusively within New York City's limits. Every other day for about 5 months I would walk between two and six miles with a weighted pack, starting with about twenty pounds of water and slowly ramping up to about forty-five pounds. By the end I was doing six miles with forty five pounds and feeling quite comfortable. All this was done in a small city park five minutes from my apartment. (Bonus that the park had a flight of stairs with 138 steps that I would do ten to fifteen laps on for approximately a mile of stair climbing.) This got my legs in really solid shape for the beginning of the hike and also caused a bit of foot expansion prior to beginning the hike, allowing me to get the right shoe size prior to embarking.
Speaking of shoes... Shoes are the most important piece of gear. Try a bunch out extensively. This is another great benefit of training. You will learn quickly which shoes work for you. Had I not done training hikes, I would have started the trail with a pair of shoes that I loved - but that gave me terrible blisters after about 5 miles.
“I start my hike in a month and haven't done any training yet. What do I do”?
Don't get discouraged if you're short on time before your hike begins. Just do something, and start small. Listen to your body. It will tell you when to ease up. Remember, at this point your main focus needs to be about injury prevention. This close to your hike, hopefully you have all your gear and can train with your actual load. Do this, and repack the pack each time. It will help you learn how to pack your pack for maximum comfort and it will start beating up your body in those pack-specific places like your hips and shoulders. When you get to the trail, allow yourself a slow start. Don't go for big miles in the first three weeks. Remember there is plenty of time for crushing miles. What you need to establish is a solid fitness base on which you can build yourself into a super hiker. It takes time and near as I can tell there are no shortcuts.
I hope you've found my insights helpful but please remember these are my ideas, theories, and anecdotes from largely my own personal experience. I am not a medical professional and you would do well to consult one before beginning any physical fitness routine because, you know... lawyers. So don't sue me if you get hurt being a dumbbell. Thanks.