According to Better Health Channel, there are many benefits to cycling as a form of exercise:

• Cycling is low impact: there is arguably less strain and injury involved than most other forms of exercise. 
• It's a good muscle workout: Cycling targets and uses all the major muslce groups as you pedal. 
• It does not require high levels of physical skill.
• Cycling incereases stamina, strength, and aerobic fitness.
• It can be as intense of a workout as you make it, meaning its adjustable in terms of its difficulty level. 
• It can be fun. 
• It is an excellent alternative to being sedentary, like one may be driving or using public transportation.  

Health Benefits of Cycling 

• Increased cardiovascular fitness
• Increased muscle strength and flexbility 
• Increased joint mobility 
• Less stress
• Improved posture and coordination
• Increased bone strength
• Decreased body fat levels
• Prevention/management of disease
• Decreased levels of anxiety and depression