Swimming is an individual or team racing sport that requires the use of one's entire body to move through water. The sport takes place in pools or open water (e.g., in a sea or lake). Competitive swimming is one of the most popular Olympic sports with varied distance events. In addition to these individual events, four swimmers can take part in either a freestyle or medley relay. A medley relay consists of four swimmers who will each swim a different stroke, ordered as backstroke, breaststroke, butterfly and freestyle.

Swimming each stroke requires a set of specific techniques; in competition, there are distinct regulations concerning the acceptable form for each individual stroke There are also regulations on what types of swimsuits, caps, jewelry and injury tape that are allowed at competitions Although it is possible for competitive swimmers to incur several injuries from the sport, such as tendinitis in the shoulders or knees, there are also multiple health benefits associated with the sport.

Competitive swimming became popular in the 19th century. The goal of high level competitive swimming is to break personal or world records while beating competitors in any given event. Swimming in competition should create the least resistance in order to obtain maximum speed. However, some professional swimmers who do not hold a national or world ranking are considered the best in regard to their technical skills. Typically, an athlete goes through a cycle of training in which the body is overloaded with work in the beginning and middle segments of the cycle, and then the workload is decreased in the final stage as the swimmer approaches competition.
The practice of reducing exercise in the days just before an important competition is called tapering. Tapering is used to give the swimmer's body some rest without stopping exercise completely. A final stage is often referred to as "shave and taper": the swimmer shaves off all exposed hair for the sake of reducing drag and having a sleeker and more hydrodynamic feel in the water Additionally, the "shave and taper" method refers to the removal of the top layer of "dead skin", which exposes the newer and richer skin underneath. This also helps to "shave" off mere milliseconds on your time.

Swimming is an event at the Summer Olympic Games, where male and female athletes compete in 16 of the recognized events each. Olympic events are held in a 50-meter pool, called a long course pool.
There are forty officially recognized individual swimming events in the pool; however the International Olympic Committee only recognizes 32 of them. The international governing body for competitive swimming is the Fédération Internationale de Natation ("International Swimming Federation"), better known as FINA.

 open water swimming, where the events are swum in a body of open water (lake or sea), there are also 5 km, 10 km and 25 km events for men and women. However, only the 10 km event is included in the Olympic schedule, again for both men and women. Open-water competitions are typically separate to other swimming competitions with the exception of the World Championships and the Olympics.
Swim styles
In competitive swimming, four major styles have been established. These have been relatively stable over the last 30–40 years with minor improvements. They are:
Butterfly
Backstroke
Breaststroke
Freestyle
In competition, only one of these styles may be used except in the case of the individual medley, or IM, which consists of all four. In this latter event, swimmers swim equal distances of butterfly, then backstroke, breaststroke, and finally, freestyle In Olympic competition, this event is swum in two distances – 200 and 400 meters. Some short course competitions also include the 100-yard or 100-meter IM – particularly, for younger or newer swimmers (typically under 14 years) involved in club swimming, or masters swimming (over 18).

Swimming is a healthy activity that can be done by most people throughout their life. It is a low-impact workout that has several mental and bodily health benefits all while being a good recreational activity. Swimming builds endurance, muscle strength, and cardiovascular fitness. Correspondingly, it also improves weight loss while being a safer alternative of working out for someone who is injured or for women who are pregnant. Swimming requires less effort than other sports, but the athletes will get the results they are looking for.
The U.S. Census Bureau reports that two and a half hours per week of aerobic physical activity such as swimming can decrease the risk of chronic illnesses, and help regenerate healthy cells. Furthermore, swimming is linked to better cognitive function; also lowering the risk of Type II diabetes, high blood pressure, and a stroke. It can improve lung and heart strength while it tones muscles in a full body workout. People can typically exercise longer in water than on land without increased effort and minimal joint or muscle pain. When in the water the body undergoes less physical stress thus releasing pressure from the joints.
In addition to the physical benefits of swimming, lower stress levels and occurrences of depression and anxiety are known to decrease while swimming. Swimming is a meditation sport meaning there is an increase of blood flow to the brain which allows an individual to evaluate stressors more calmly. The activity can help increase the memory for older aged individuals who suffer from dementia.

Common injuries in swimming:
The rotator cuff in the shoulder is most susceptible to injury in swimmers. Injury to the rotator cuff results from repeated trauma and overuse. The joints are more prone to injury when the arm is repetitively used in a position above the horizontal line of the body. This position occurs in each of the four swimming strokes in every cycle of the arms. Out of the four tendons in the rotator cuff, the supraspinatus is most prone to tearing. Rotator cuff impingement is due to pressure on the rotator cuff from part of the scapula as the arm is raised.
The best way to prevent injury is catching the issue early. Typically, poor technique and over excessive use of the muscle group can be the primary causes of injury. Through communication between swimmers, coaches, parents, and medical professionals, any issue can be diagnosed prior to a serious injury. Additionally, proper warm-up, stretches, and strength training exercises should be completed before any rigorous movements.

In treating a rotator cuff injury, the most important factor is time. Due to the nature of the joint being primarily stabilized by muscle and tendon, the injury must be fully healed to prevent recurrence. Returning to swimming or other demanding exercises too soon can result in degeneration of a tendon which might result in a rupture. During the rehabilitation period, focus should be placed on rotator cuff and scapular strengthening.
Another common injury is breaststroke knee, also known as swimmer's knee. This injury is caused by the kicking movement used while swimming breaststroke. The kicking movement will cause wear and tear on the knee and it will eventually lead to constant pain. In recent studies it has been found that initially, the pain is only experienced when the kick was executed, but eventually the pain spread to other regular day-to-day activities, athletic and non-athletic.