Kickboxing is a martial arts style that teaches a mix of punches, kicks, knees and elbow strikes. The style's founders, Tatsuo Yamada and Osamu Noguchi, borrowed elements of Muay Thai fighting from Thailand, Taekwondo from Korea, and karate to make the modern form of kickboxing. This combination of styles and techniques makes for a well-rounded approach to fighter fitness and is an intense workout for several muscle groups in the body.
Kickboxing involves vigorous forearm and elbow strikes targeted at the head and upper body of your opponent. You might notice that after a great kickboxing fitness class your forearms are really sore. That's because there are a group of muscular fibers called the wrist extensors that run along the back of the forearm. There isn't much muscle covering the bones of the forearm, but kickboxing makes the most use of them. Most of the power for elbow strikes comes from the latissimus dorsi muscles of the lower back, but the wrist extensors are the muscles that absorb most of the impact.
The Muay Thai clinch is an integral part of mixed martial arts-style kickboxing. This technique involves wrapping your arms and hands around the back of your opponent's neck to manipulate their body and deliver elbow and punching strikes up close. Working in the clinch directly engages the muscles of your core. Clinching constantly flexes the transverse abdominus and the rectus abdominis muscles that run along the abdomen. Also, the obliques, which strengthen the sides of the trunk, are receiving a workout. Leaping knee strikes are thrown from the clinch position as well. These techniques require an explosive output from the hip abductors and flexors to elevate the body into striking range.
Kickboxing employs a rather narrow range of kicks, mostly used for close-contact fighting with little subterfuge. The high roundhouse, the front straight kick and crescent kicks to the legs are often utilized in both competitive and recreational forms. This results in the repetitive use of muscle groups in your legs and core that will give you a high-intensity workout. Kickboxing strengthens the quadriceps in the upper leg and hip abductors for kicking power but also toughens the soleus and tibialis anterior muscles of the lower leg. These narrow muscles and a thin layer of skin are the only thing standing between your shin bone and your target.
Standard boxing punches which are thrown in kickboxing are often used in combination with kicks, knees and elbow strikes. This addition of six other points of attack makes punching in kickboxing more about coordination than brute strength. Putting together punching combinations requires muscular endurance, the ability to perform the same strenuous action over and over again. Most punching combos start with the jab. When thrown repeatedly, the jab will tax the deltoids muscle group in your shoulder. The cross punch is thrown from the lower body up, and engages the hip muscles, the flexors and abductors, as well as the deltoids in the shoulder.