Staying Motivated Edit
Motivation is key in becoming great at anything, including parkour. If you don't want to go out and do the training, and do the work, you will never be successful. A good way to stay motivated is to have some quotes, or an inspirational speech that you read. You can never give up, but if you do, you have to remember that you cannot gain anything from doing nothing. You are already in pain, it doesn't matter what for, then why don't you get something out of it? If you want to be successful as badly as you want to breathe, sleep, or eat, then you'll be successful. Try to keep an image in your mind of what you will become, and how great you'll be to stay motivated.
Training can and will be difficult when first starting out, but in the end it will be rewarding. Training is what will give you that special edge on your parkour. To get the best results you possibly can, you must give 110% of your energy into training. When you first start training it is very difficult to stay motivated to keep going, but when you have been training for a fair ammount of time it is pratically impossible to stop. Strength does not come from physical capacity, it comes from an indomitable will.
Parkour is about using your body, so with that in mind, you will need to be in a good physical standing. Also, you want to make sure that your are not overweight or underweight, alot of parkour will require upper body strength so being light will help a lot. Try your hardest to stay away from fatty, greasy, high in carb, and sugary foods. Try to find a diet that works well for you, and that is well balanced. Again, it will be hard at first, but you will get used to it very quickly.
There is no way for me to explain how important it is to stretch. You will never be able to do any kinds of flips, spins, or any fancy manouvriers if you do not stretch. It would be wise to stretch when you wake up, start your workout, end your workout, and before you go to sleep. When preforming a stretch, never just do it once, it will won't get you the best results. Try doing three sets of each stretch with five second intervals. http://www.bodybuilding.com/exercises/finder/lookup/filter/exercisetype/id/3/exercisetype/stretching You do not have to do all of the stretches in the link provided. Just try and find the best stretches that will stretch all of your muscles.
Any bodybuilder, martial artist, or person who worksout will all tell you how important it is to develop your core. Your core consists of twenty nine different muscles all working in unison to keep your body in balance, and to protect it. If you have a strong core, it will be much easier to train and build all of your other muscles. Unlike your other muscles, you can train your core everyday. There are many different exercises that train your core:
*Jackknife sit ups
*Static holds (planks)
*Hanging knee ups
*Hanging leg lifts