Bicycling, also called biking or cycling, is the use of a bicycle for personal transportation, exercise, or touring and other forms of recreation. A bicycle is defined as a single-track human-powered vehicle (HPV) driven by pedals and consisting of two wheels attached to a frame, one wheel behind the other. Tricycles and unicycles are often referred to informally as bikes, even though they have three wheels or one wheel, respectively, rather than two.


People ride bicycles for one of several reasons: personal transportation to and from school or work; physical exercise; athletic competition, usually races; and touring or other forms of noncompetitive recreation. Some specialized purposes of bicycling include:

The activity, exercise, and overall experience of bicycling offers individuals numerous fitness benefits including:



Eddy Merckx, a Belgian cyclist, has been called “the most accomplished rider that cycling has ever known.” He has won the Tour de France five times, the first being in 1969.

In 1972, at age 27, Merckx set the hour record—the longest distance completed on a bicycle in one hour. His achievement of 49.431 km held the record for twelve years. He also established several other cycling records. He has the most wins in one cycling season (54) and the most career victories (525).

The sport of cycling is comprised of five one-day road races termed “monuments.” During his career, Merckx won nineteen monument races. Twice, he won all of the monuments in a year.

Unfortunately, Merckx's career was blemished. Three times, he tested positive for doping. Merckx contested, citing that cycling's standards are much more stringent than other sports.

In 1977, Merckx retired but is still involved in the sport as a race commentator and advisor. For instance, Merckx helped Qatar win the right to host the 2016 UCI Road World Championships, an annual world event for bicycle road racing organized by the Union Cycliste Internationale (UCI).

It is estimated that 73% of American children between the ages of 5 and 14 ride bicycles, or about 30 million child cyclists. The highest rate of bicycle-related injuries in the United States is found in children between the ages of 9 and 15, boys being three times as likely to be injured as girls. In adulthood, that ratio rises to about five times the number of men injured in biking accidents when compared to women.

Bicycles are also associated with a fairly high level of traumatic injuries and falls, overuse injuries, and sunburn or dehydration due to exercising outdoors in hot weather without appropriate precautions. Most bicycle-related injuries affect males and are associated with high-speed riding; most serious injuries and fatalities involve collisions with automobiles or motorcycles. The U.S. Department of Transportation stated that in 2015, 818 bicyclists were killed in the United States, along with about 45,000 people being injured due to biking accidents. The average age of a bicyclist killed on U.S. roads is 45 years. Each year in the United States there are about 800 deaths related to bicycling and approximately 23,000 hospital admissions. Of the roughly 4.5 million children injured each year during participation in sports or recreational activities, 10%–20% are involved in bicycling accidents.

The rates of bicycle-related injuries are higher for mountain bikes (also called all-terrain or off-road bicycles) and for bicycle-motocross or BMX bikes. Mountain bikes presently account for over 60% of new bicycle sales in the United States. While mountain bike riders of all ages account for only 3.7% of bicycle injuries overall, up to 51% of these recreational and 85% of competitive mountain bikers sustain injuries each year. About 6.3% of BMX riders who participate in competitions are injured each year.


Bicycling first emerged as a form of transportation and leisure-time activity in the nineteenth century. The prototype of the modern bicycle was a two-wheeled device made mostly of wood, called a draisine after its inventor, a German named Karl Drais (1785–1851). Drais himself referred to his 1817 invention as a Lauf-maschine or running machine. The name bicycle was first used by French manufacturers of what were then called velocipedes in the 1860s. These early all-metal bicycles were called boneshakers in the United States because they had solid iron wheels without tires that made for a rough ride, particularly on country roads. Until the early 1890s, bicycling was primarily a sport for well-off gentlemen; it was only with the invention of the safety bicycle in the late 1880s that what had been a somewhat dangerous plaything for the well-to-do became a safe and inexpensive means of transportation for men—and women—of all ages from childhood on up.

The features of the safety bicycle that made it suitable for a mass ridership were the addition of a chain drive to the rear wheel; a diamond-shaped frame that added strength without additional weight; a safe and reliable steering mechanism; and air-filled tires that smoothed the ride. The 1890s have been called the Golden Age of Bicycling; cycling clubs sprang up all over Europe and North America. But perhaps the most important aspect of the safety bicycle was its contribution to the emancipation of women. The bicycle made it possible for respectable women to wear first bloomers and then pants. It gave them unprecedented mobility and personal freedom. Susan B. Anthony credited the safety bicycle with advancing the cause of women's political equality. She said, “I think [the bicycle] has done more to emancipate women than anything else in the world. It gives women a feeling of freedom and self-reliance. I stand and rejoice every time I see a woman ride by on a wheel…the picture of free, untrammeled womanhood.”


Bicycling is a multipurpose form of exercise; people can cycle for practical reasons—to run errands, to lose weight, as part of their job, or as personal transportation to and from school or work. People can join bicycling clubs in order to compete in races or stunt contests, or to meet other cycling enthusiasts. Some people use bicycling as a form of tourism; there are groups that sponsor bike tours of national parks or other scenic areas that may range in length from day trips to weeklong or month-long tours. There are even instances of cyclists who have taken to the road permanently; one Australian traveled by bicycle continuously for 27 years. The present record for long-distance cycling is a German who left home in 1962 and has been touring the world by bicycle ever since. He has visited 192 countries and makes his living as a photojournalist.

Types of bicycles

The following are the most common types of bicycles used in Europe and North America:


Preparation for a bicycle ride should always include checking the condition of the bicycle's safety features (brakes, lights, reflectors) as well as the tires and frame. Other preparations include checking the weather forecast, particularly if the ride is going to be an all-day trip or longer, as changes in the weather can affect road conditions and motorists' behavior as well as the bicycle rider's comfort.

Another aspect of preparation is planning the travel route beforehand. This step is particularly important if the trip will involve sharing the road with heavy traffic or traveling off-road in areas with difficult or poorly managed trails. The Pedestrian and Bicycle Information Center (PBIC) has a six-page Bikeability Checklist on its website that allows people to evaluate the various traffic, engineering, and other environmental issues that affect the safety and comfort of bicycling in their local area.

Bicycle selection and fitting

The first step in bicycling is to decide what type of bike best fits the user's needs. Those who want a bicycle for running errands or brief rides around the neighborhood may find their needs met by a simple utility bicycle, while those who are interested in racing, long-distance touring, off-road travel, or stunt performances will want to consider specialized bicycles. Cost may be a factor for some people: while used utility bicycles for adults can be purchased for about US $100 and new ones for US $150–300, specialized mountain, touring, or BMX bikes can run from US $1,000–3,000 or even higher when purchased new. New children's bikes commonly run between US $60 and US $140 as of 2016.

The next step is fit. This step is critical to health as well as safety because a bicycle poorly fitted to the rider can place extra strain on knees, shoulders, back, wrists, and neck, leading to possible overuse injuries. In addition, a poor fit between bike and rider increases the risk of a fall or other accident. The following are the key dimensions involved in selecting a bicycle for proper fit:

Protective equipment

The most essential item of protective equipment is a properly fitted helmet. Bicycle helmets reduce the risk of bicycle-related injuries to the head by 74%–85% and to the nose and upper face by approximately 65%. One reason why riders often omit to wear this necessary protection, however, is poor fit. Helmets come in a range of sizes with either sizing pads or an interior fit ring to customize the fit. The helmet should sit low on the rider's forehead, one or two finger-widths above the eyebrow. It should not rock back and forth on the head, and the chin strap must be tight and properly adjusted. Children should wear helmets that fit them now, not ones that are too large in the expectation that they will “grow into” them. A helmet that has been involved in a crash or damaged should be replaced.

Other items of protective equipment include:

Education and training

Education and practice are vital in safe and healthy cycling. Bicycle safety includes knowing the rules of the road as well as the safety features and riding characteristics of one's bike. Bicycles are considered vehicles from the standpoint of traffic engineering and law enforcement even though they are human-powered rather than motorized, and cyclists can be ticketed for traffic violations in the same way as motorists.

Caregivers of children old enough to be interested in bicycling should inform themselves about bicycle safety and should model proper attention to the rules of the road and other aspects of safe cycling. They should also see to it that the child attends a class in bicycle safety or take the child to a family biking workshop. As noted above, some school districts include bicycle safety instruction at the elementary school level; in other parts of the United States and Canada, workshops in bicycle safety are offered by parks and recreation departments or by local bicycle clubs.

Police officers and medical personnel who use offroad bicycles in their professional work are required to complete special courses in the maintenance and repair of their bikes as well as techniques for riding safely in heavy city traffic. Many mountain biking clubs also offer courses or workshops for new members in the special skills and techniques needed for safe off-road biking.


Health risks from bicycling fall into three general categories: traumatic (external) injuries; overuse (internal) injuries; and injuries or disorders related to environmental exposure. Traumatic injuries are most commonly the result of collisions with automobiles, motorcycles, or stationary objects. Most bicycle-related injuries affect the rider's arms or legs, followed in order of frequency by injuries to the head, face, abdomen, and neck. Many external injuries are superficial scrapes and cuts, sometimes referred to as “road rash.” However, road rash injuries occasionally involve the full thickness of the rider's skin, requiring the surgical removal of embedded dirt, stones, and other debris. Sprains, strains, and dislocations are also common injuries resulting from falls or collisions. Head injuries occur in 22%–47% of injured bicyclists; they are responsible for more than 60% of all bicycle-related deaths and the majority of long-term disabilities.

Overuse injuries are most likely to affect competitive racers and those who use bicycles for several hours a day in the course of their occupation. Overuse injuries include compression of the nerves in the wrist due to gripping the handlebars; muscle cramps in the neck, shoulders, and back due to improper seat height or the use of the wrong size frame for the rider's height; inflammation of the Achilles tendon in the foot; hip pain caused by the repetitive sliding of the soft tissue of the hips over the underlying bone; and saddle sores. Both men and women are at risk for soreness or bruising in the region of the genitals from pressure on the bicycle saddle. Men in particular may experience tingling or numbness in their external genitals resulting from compression of the pudendal nerve, and there are occasional reports of temporary impotence in male cyclists.

BMX bike—
A specialized small-framed bike with wide tires used in dirt jumping and other stunt competitions. BMX bikes developed in California in the 1970s from customized alterations of a Schwinn bicycle called the Stingray.
Mountain bike—
A lightweight bike with frames designed for off-road use, knobby or studded tires, and disk brakes on the newer models. Mountain bikes are designed to withstand rough trails and such obstacles as logs or rocks. The term “mountain bicycle” was first used in 1966 but the type as a whole did not become popular until the 1980s.
Road rash—
An informal term for scrapes and abrasions to the skin resulting from a bicycle accident. Some road rash injuries are severe enough to require surgical repair.
Utility cycling—
The use of a bicycle for commuting to and from work or for delivering goods, as distinct from recreational cycling.

People who have traumatic injuries as the result of collisions or falls while cycling may need to be treated by specialists in emergency medicine, neurologists, orthopedic surgeons, oral surgeons, ophthalmologists, or physical therapists. Those who develop overuse injuries from cycling may require treatment from physical therapists in addition to medications or surgical treatment from specialists.

Environmental injuries include sunburn or windburn from exposure to the elements, and dehydration and heat exhaustion from riding in hot, humid weather without adequate water intake. Cyclists should always wear a hat and take a water bottle and extra sunscreen with them when riding for more than a few minutes in the sun.


Bicycling is an important subject to the National Highway Traffic Safety Administration (NHTSA) and other government agencies concerned with the need to make streets and roadways safe for all types of vehicles. Some studies have already discovered ways to improve the visibility of traffic signals and signage; to take cyclists as well as motorists into account when engineering curves and grades during highway construction; and to design safety education programs that will reach many different types of audiences.


Bicycling is known to benefit participants by increasing muscle strength and flexibility, endurance, and lung capacity. It helps in weight reduction, lowering blood pressure, and lowering the risk of depression, stroke, and cardiovascular disease. Many people also find that bicycling can lower their transportation costs by minimizing the use of an automobile, while others enjoy the opportunities for slow-paced travel through national parks and other scenic areas afforded by cycling. Still others find that bicycling is a good way to bring family members or friends together for group outings.

Bicycling is a topic of research in a number of different fields of medicine and public health. As of 2017, several clinical trials continue to gather valuable medical information with respect to the use of bicycling as a form of low-impact exercise for persons with osteoarthritis and as part of a treatment program for obesity. Researchers in the field of public health are studying the rates, risk factors, and distribution of traumatic and overuse injuries related to bicycling, and various approaches for reducing the risk of such injuries.

See also Dehydration ; Heat exhaustion ; Sunburn .



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American College of Sports Medicine, 401 W Michigan St., Indianapolis, IN, 46202-3233, (317) 6379200, Fax: (317) 634-7817, .

American Council on Exercise, 4851 Paramount Dr., San Diego, CA, 92123, (858) 576-6500, (888) 825-3636, Fax: (858) 576-6564, support@acefitness. org, .

American Trauma Society, 201 Park Washington Ct., Falls Church, VA, 22046, (703) 538-3544, (800) 556-7890, Fax: (703) 241-5603,, .

International Mountain Bicycling Association (IMBA), PO Box 20280, Boulder, CO, 80308, (303) 545-9011, (888) 442-4622, Fax: (303) 545-9026,, .

International Police Mountain Bike Association (IPMBA), 583 Frederick Rd., Ste. 5B, Baltimore, MD, 21228, (410) 744-2400, Fax: (410) 744-5504,, .

National Center for Injury Prevention and Control (NCIPC), 1600 Clifton Rd., Atlanta, GA, 30329, (800) 232-4636, .

National Highway Traffic Safety Administration (NHTSA), 1200 New Jersey Ave. SE, West Building, Washington, DC, 20590, (888) 327-4236, .

Pedestrian and Bicycle Information Center, 730 Martin Luther King, Jr. Blvd., CB# 3430, Chapel Hill, NC, 27599, (888) 823-3977,, .

Safe Kids Worldwide, 1255 23rd St. NW, Ste. 400, Washington, DC, 20037, 202-662-0600, Fax: 202-393-2072, .

Rebecca J. Frey, PhD
Revised by Laura Jean Cataldo, RN, EdD

  This information is not a tool for self-diagnosis or a substitute for professional care.