Conditioning and training
When fighting, it is important to be physically fit. Both endurance and physical strength are important. The best way to get in shape, if you are in high school or college, is to at least do intramural sports. If you are physically weak or underdeveloped in strength or fitness then start at first with brisk walking and free hand exercises like push ups and chin ups. At the next level Wrestling and football will be the best programs for you to join for overall conditioning. For strength and flexibility gymnastics and track events (shot put, pole vaulting and most sprinting events) are good choices. For endurance, swimming and cross-country running. You should also practice some form of fighting, from just a friendly match with friends to training at a boxing gym. If you are not in high school or college, you should run and buy some weights. Make sure to measure the distance and time you run and the amount and reps you lift so as to measure improvement. You should also make some effort to include training in your everyday life. For example, you can start riding a bike to work (or school). Alternatively, you can join a gym, though memberships are often overpriced and not particularly useful. Bodyweight exercises can be an excellent alternative to weights and machines. Martial arts classes, while they can be useful, are generally not as focused on actual fighting as a boxing gym would be. In a class always do stretching exercises for the whole body in very, very slow motion so as not cause micro tears on your muscles.
There are several exercises geared specifically towards fighting. One of the best is pummeling. Pummeling consists of taking two 5-8 pound weights, one in each hand, and punching with them for a period of time. It is important to maintain proper form throughout the exercise.
Another good exercise is shadowboxing. When shadowboxing, a fighter fights an imaginary opponent, preferably in front of a mirror. This can condition endurance and improve technique.