Practicing MMA (mixed martial arts), kickboxing, and boxing for fitness has become extremely popular. You don't have to fight or compete to take advantage of the same techniques, exercises, and methods professional fighters use to stay in awesome shape.
The jab is one of the most basic strikes. It is used in competition to make a quick contact with your opponent, establish distance, and wear your opponent down. The jab is typically not a "fight ender" or a knockout punch...but this does happen occasionally.
Start from your basic stance....we'll assume a traditional stance if you are right handed. If you're left handed, simply switch everything (as I'm sure you're used to). Put your left foot forward, to pointing almost straight ahead, with the right foot back about 18 inches, shoulder width apart, and to pointing at 45 degree angle to the right. Your upper body/chest should be perpendicular to a 2 o'clock position. Your stance should be comfortable. Raise your left fist under your left eye, about 12 inches from your cheek. Knuckles are perpendicular to your face. Imagine holding a pencil - the eraser (or point) should be pointing at your cheek. Raise right fist to your right cheek. Keep your elbows in to your sides and relax...don't tense up. You're now ready to go.
The jab is executed with the lead hand and contacts your opponents chin or torso. We'll focus on contacting the chin for now. Drive the fist straight forward, as if your fist is traveling in a tube. The elbow does not come out to the side, it stays underneath your arm. You drive this punch with your shoulder, not the elbow. Drive the fist forward over top of your front thigh and at the last split second, rotate the fist so the knuckles are parallel with the floor. The imaginary pencil you have should be parallel with the floor.
Do not lock out the elbow...ever. This can cause injury, so stop your punch (and other punches and strikes) short of lockout. After contact, bring your hand back to the starting position as fast as you can. Tell yourself "put it back where I got it." The jab should be performed as quickly as possible. Imagine snatching a fly off of the wall. That's who quickly you want to execute.
To jab to the body, simply bend your knees to lower your body a level while executing. You don't throw the punch at a down angle. Lower your body and drive the jab straight.
Let's recap-drive the jab with the elbow underneath the arm as if in a tube, rotate the fist and arm right at contact, and bring it back where you got it quickly.
Practicing the jab is an integral part of your MMA, kickboxing, or boxing for fitness exercise routine. Practice it correctly from the beginning and it will become second nature.
This lesson is not intended for sparring or contact with another individual. That should only occur under supervision of a trained instructor. If you are using a heavy bag or other equipment, be sure you have the proper protective equipment (gloves, wraps, etc.) and understand how to use it properly before trying out the jab.
Source: http://www.associatedcontent.com/article/2093183/mma_kickboxing_and_boxi...