How important is warming up?

Often when I go to big commercial gyms I see people diving on the pull up bars for a warm up, I couldn’t think of a worse bit of equipment to warm up on.  Doing pull ups is like warming up on a lat pull down bar with your own weight as the plate load, very dangerous and will easily lead to injuries.  Warming up is often overlooked by bodybuilders and most weight lifters but is actually hugely important for the following reasons.

• Lubricating the joints- hitting the treadmill before a squat session for example will get the blood pumping around the body and the joint movement in the legs will become much better.  If you start doing squats without warming up they will feel stiff, you will often hear cracking or popping as well.
• Getting into the movement- by performing warm up sets you get your reps into good form meaning you will get much better isolation on the muscle group you are working.
• Gets the nervous system working- sometimes when you perform an exercise you haven’t for awhile you will notice yourself shaking all over the place, perform lots of warm up sets gradually increasing the weight will get rid of this problem.
• Warming up the muscles- increasing body temperature, increases muscle temperature thus increasing muscle elasticity making it less likely you will pull a muscle.