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Whether shadow-boxing or using a speed bag or heavy bag, new boxers must concentrate on using proper form when unleashing a blow. Using proper form means that you'll need to develop a good sense of balance so that you're not thrown off balance by throwing a punch. Also, practice keeping your hands in front of your face and returning to this defensive position after throwing a punch. Before punching, keep your hands close to your face and your elbows tight against your body. Put your weight into the punches you throw, and follow through with each punch. This will help you land punches effectively and accurately on your opponent's head or torso. at your opponent to keep them at a distance. Jabbing is a basic punch which you'll usually do with your weaker front hand. The jab is a short punch. To jab, drive your fist straight into your opponent's face or torso. To maximize the effectiveness of the jab, professional boxers twist their arm and wrist just before making contact with their opponent. As opposed to a jab, which is thrown straight in front of the body, deliver a cross punch by jabbing your dominant hand in a slightly upward motion across your body. If your opponent throws a left jab at you, they'll leave themself open for your right hook. Keep your weight on the balls of your feet, and aim your punch across your body towards the right side of your opponent's torso or face. Use the cross on its own to counter a jab, or put the jab and cross together for a 1-2 combo. The shoulder helps power the cross punch. Also pay attention to your feet when throwing a cross. As you throw the punch, move your body weight from your rear foot up to your front foot. The hook can be delivered to the head or body of the opponent. Lean your body to the side that you plan to hit from, and circle your arm around to punch the opponent in the unprotected side of their head or body. The hook is often used in combination with other punches. The hook's sweeping delivery is its chief drawback, as it can leave you susceptible to a counterpunch. So, if you and your opponent are exchanging swift jabs back and forth, this isn't the time to wind up for a hook. The uppercut is an upward blow unleashed by either hand that is highly effective when in close quarters. Throw an uppercut when you're close to your opponent's body. To uppercut, lower your arm to about waist-height, then swing it upward in an explosive burst. Aim to his your opponent squarely on their chin. Don't try to throw an uppercut form more than 1 foot (0.30m) away, or you may miss and leave yourself open to a counter-attack to your body. After they become adept at delivering a variety of punches, fighters usually develop combinations, in which they release a devastating flurry of blows on their opponent. The first combination most boxers learn is the 1-2 combo (a jab followed by a cross). Try putting together different combos of your own. Rely on building combos around punches that you feel good throwing. Another effective combo adds a hook to the 1-2 combo. If you're right-handed, this would be a left jab followed by a right cross and ending with a left hook.

Summary:
Practice punching on a bag to develop proper form. Jab Throw a cross punch to counter punch a jab. Throw a hook when you have time for a slower, powerful punch. Use an uppercut to seriously damage your opponent. Combine punches to hit an opponent multiple times in a row.