Cycling, also, when on a two-wheeled bicycle, called bicycling or biking

Health effects

The health benefits of cycling outweigh the risks, when cycling is compared to a sedentary lifestyle. A Dutch study found that cycling can extend lifespans by up to 14 months, but the risks equated to a reduced lifespan of 40 days or less. Mortality rate reduction was found to be directly correlated to the average time spent cycling, totaling to approximately 6500 deaths prevented by cycling. Cycling in the Netherlands is often safer than in other parts of the world, so the risk-benefit ratio will be different in other regions.Overall, benefits of cycling or walking have been shown to exceed risks by ratios of 9:1 to 96:1 when compared with no exercise at all, including a wide variety of physical and mental outcomes.
The physical exercise gained from cycling is generally linked with increased health and well-being. According to the World Health Organization (WHO), physical inactivity is second only to tobacco smoking as a health risk in developed countries, and is associated with 20-30% increased risk of various cancers, heart disease, and diabetesand tens of billions of dollars of healthcare costs.The WHO's 2009 report suggests that increasing physical activity is a public health "best buy", and that cycling is a "highly suitable activity" for this purpose. The charity Sustrans reports that investment in cycling provision can give a 20:1 return from health and other benefits. It has been estimated that, on average, approximately 20 life-years are gained from the health benefits of road bicycling for every life-year lost through injury.
Bicycles are often used by people seeking to improve their fitness and cardiovascular health. Recent studies on the use of cycling for commutes have shown that it reduces the risk of cardiovascular outcomes by 11%, with slightly more risk reduction in women than in men.In addition, cycling is especially helpful for those with arthritis of the lower limbs who are unable to pursue sports that cause impact to the knees and other joints. Since cycling can be used for the practical purpose of transportation, there can be less need for self-discipline to exercise.
Cycling while seated is a relatively non-weight bearing exercise that, like swimming, does little to promote bone density.^[Cycling up and out of the saddle, on the other hand, does a better job by transferring more of the rider's body weight to the legs. However, excessive cycling while standing can cause knee damage It used to be thought that cycling while standing was less energy efficient, but recent research has proven this not to be true. Other than air resistance, there is no wasted energy from cycling while standing, if it is done correctly.
Cycling on a stationary cycle is frequently advocated as a suitable exercise for rehabilitation, particularly for lower limb injury, owing to the low impact which it has on the joints. In particular, cycling is commonly used within knee rehabilitation programs, to strengthen the quadriceps muscles with minimal stress on the knee ligaments. Further stress of the knee can be relieved by changing seat heights and pedal position to improve the rehabilitation. Cycling is also used for rehabilitation after hip surgery to manage soft-tissue healing, control swelling and pain, and allow a larger range of motion to the nearby muscles earlier during recovery.^[As a result, many institutions have established a rehabilitation protocol that involves stationary cycling as part of the recovery process. One such protocol offered by Mayo Clinic recommends 2–4 weeks of cycling on an upright stationary bike following hip arthroscopy, starting from 5 minutes per session and slowly increasing to 30 minutes per session. The goal of these sessions are to reduce joint inflammation and maintain the widest range of motion possible with limited pain.

As a response to the increased global sedentary lifestyles and consequent overweight and obesity, one response that has been adopted by many organizations concerned with health and environment is the promotion of Active travel, which seeks to promote walking and cycling as safe and attractive alternatives to motorized transport. Given that many journeys are for relatively short distances, there is considerable scope to replace car use with walking or cycling, though in many settings this may require some infrastructure modification, particularly to attract the less experienced and confident.

An Italian study assessed the impact of cycling for commute on major non-communicable diseases and public healthcare costs. Using a health economic assessment model, the study found a lower incidence of type 2 diabetes, acute myocardial infarction, and stroke in individuals that cycled compared to those that did not actively commute. This model estimated that public healthcare costs would reduce by 5% over a 10-year period.