Weightlifting is the most exciting strength and power sport ever developed.  It is a sport that involves lifting a barbell overhead.  It is the only event involving the use of heavy weights that is part of the Olympic Games.  The sport consists of two lifts.  The first lift is always the SNATCH.  The snatch is done by lifting a barbell from the floor to arm's length overhead in one continuous motion.  It is one of the most difficult, explosive and elegant events in sport.  The second lift is called the CLEAN & JERK.  This lift involves lifting a barbell from the floor to the shoulders in one continuous motion and then, in a second motion, bringing the weight to arm's length overhead.  It is by far the single greatest test of strength in all of organized athletics.

Why weightlifting is important for athletes to incorporate...
Both lifts done in the sport of weightlifting requires great strength, power, explosion, quickness and flexibility.  The only component that weightlifting doesn't really challenge is endurance.  Each lift lasts well under 10s, and training reflects that.  When an athlete does either one of the lifts or a variation of one of the lifts, to be successful in moving the weight you have to become very proficient at what is known as triple extension.  Triple extension is extension at the ankle, knee, and hip joints.  This is also what takes place with running, speed and agility work.  When you are training in preparation for sport, you should be looking for something that will give you an "edge" or competitive advantage over your opponent.  One of those 'competitive advantages' is power - the ability to move an object as quickly as possible over a given distance.  In athletics, this can range from moving your body mass quickly to moving an external load.  So what does triple extension have to do with power? This explosive extension of the knee, hip, and ankle is the key to athletic power or explosiveness.  Triple extension is also performed in all planes and often with one leg as evidenced by agility needs that are seen throughout all athletics. 

Weightlifting movements specifically train explosive muscular actions, particular in the lower body.  If you're not incorporating weightlifting movements in your training, chances are good that you could be performing with better speed and agility.