The single most important thing to keep in mind when approaching Parkour is know your limitations. Do not attempt something beyond your skill level! Anyone who has seen the videos on YouTube knows that this is an exciting recreational activity. What is not obvious about the people in these videos is the amount of time they have invested in training, the repetition of their moves, and mental preparation for each and every obstacle they approach. Parkour is a highly disciplined activity where overcoming each challenge is 80% mental and only 20% physical. That said, strength, agility, flexibility, endurance, and coordination are key to safety and enjoyment.

First, you must establish a good foundation of skills. These are essential as you'll use them in each and every obstacle. They are: jumping, landing, and rolling. You need to learn the proper technique and then drill these moves until you don't have to think about them. When you're in mid-flight and approaching your landing, you won't have time to think about your roll. You'll only have time to do it. If you don't land correctly, you won't roll properly and you'll likely get hurt.

According to The Discovery Channel's "Human Body", running puts a strain on our legs 3 times the weight of our body, and a jump can put a strain up to 10 times our body weight. This means that if you do not learn how to land safely, you could do irreversible damage to your ligaments and tendons. It is essential that jumping, landing, and rolling are "first nature", not "second nature". Besides, if you're thinking too hard about jumping, landing, and rolling, then you're not enjoying the "art of movement".

Seeking out training by a qualified instructor or highly-experienced practitioner is the absolute best way to learn these foundational skills. As with anything else, if you learn a particular skill early and improperly, it is habit-forming. You will have a very difficult time correcting your technique later on. I recommend visiting Primal Fitness, Washington DC's "Best Gym of 2009", which provides qualified instruction in Parkour, Free Running, CrossFit, Judo, Yoga, and many other disciplines. They will teach you proper jumping, landing, and rolling technique and give you instant feedback on your execution. What is most important here is the third person perspective. These trainers have extensive experience is coaching and performing these moves. They will point our problems with your technique that could cause injury both short-term and long-term, which could prevent you from enjoying this "sport" for years to come.