A boxer's training depends largely on the point in their career at which she or he is situated. If the boxer is just a beginner, a minimal training routine might consist of learning how to hit the heavy bag, the speed bag, and the double end bag (a small bag with a cord on top and bottom connecting it to the floor and ceiling) as well as doing shadowboxing in front of a mirror, skipping, calisthenics and jogging every day, as well as an occasional practice bout inside the ring (sparring). Most beginning boxers will spend most of their early careers conditioning and establishing the fundamentals.For the amateur or professional boxer preparing for a competition or bout, however, training is much more stringent. This could include getting up at 5 am to jog, flying to a far away place to get isolated during 2 or more months before the fight, dieting, doing the same gym routine as a beginner, only that twice every day, and getting to the city hosting the fight two weeks before the fight to get used to the location's climate. Boxing is widely considered one of the most physically demanding sports in the world.
Weight
Boxing, like several other fighting sports, categorizes its competitors into weight classes. Some fighters try to take advantage of this by dieting before weigh-in so that they can be bumped down a weight class. In extreme cases, a fighter may forego solid food before the official weigh-in ceremony, and eat a lot afterward to compensate. In some very extreme cases, boxers have been forced to stop eating solid food up to three days before the weigh-in ceremony, in order to make weight for the fight. Sometimes, if a boxer doesn't make the weight agreed for on the first weight-in, he or she might go to a sauna or to jog with a jacket to sweat and lose the extra pounds, however this is mainly water that the body holds.
A boxer will generally try to have the maximum weight possible within the Boxing weight classes (s)he is fighting in, as a good boxer will be able to use his weight to his advantage
Sparring
High quality sparring is the best method to train in boxing. Sparring is "practice fighting" with the aim of training skills and fitness, not to determine a winner. Sparring should always involve use of a gumshield, head-guard and groin-guard. Sparring gloves are often more padded than gloves used in actual bouts. Sparring partners sometimes agree to practice particular types of punches or defense moves to focus their training.
Body Sparring refers to sparring where only hits to the body are allowed, not to the head. This is often used to reduce the risk of injury or for inexperienced boxers starting out in the sport.