Bicycle, also called bike, two-wheeled steerable machine that is pedaled by the rider's feet. On a standard bicycle the wheels are mounted in-line in a metal frame, with the front wheel held in a rotatable fork. The rider sits on a saddle and steers by leaning and turning handlebars that are attached to the fork. The feet turn pedals attached to cranks and a chainwheel. Power is transmitted by a loop of chain connecting the chainwheel to a sprocket on the rear wheel. Riding is easily mastered, and bikes can be ridden with little effort at 16–24 km (10–15 miles) per hour - about four to five times the pace of walking. The bicycle is the most efficient means yet devised to convert human energy into mobility.
Bicycles are widely used for transportation, recreation, and sport (see cycling). Throughout the world, bicycles are essential to moving people and goods in areas where there are few automobiles. Globally, there are twice as many bicycles as automobiles, and they outsell automobiles three to one. The Netherlands, Denmark, and Japan actively promote bicycles for shopping and commuting. In the United States, bike paths have been constructed in many parts of the country, and bicycles are encouraged by the United States government as an alternative to automobiles.
If you want to exercise in a simple and managable method, except for the bike, there is another useful epuipment which is the elliptical trainers.
An elliptical trainer or cross-trainer is a stationary exercise machine used to stair climb, walk, or run without causing excessive pressure to the joints, hence decreasing the risk of impact injuries. For this reason, people with some injuries can use an elliptical to stay fit, as the low impact affects them little. Elliptical trainers offer a non-impact cardiovascular workout that can vary from light to high intensity based on the speed of the exercise and the resistance preference set by the user.
Most elliptical trainers work the user's upper and lower body (although some models do not have moving upper body components). Though elliptical trainers are considered to be minimal-impact, they are an example of a weight-bearing form of exercise.They can be self-powered by user-generated motion or need to be plugged in for adjustment of motion and/or for supplying their electronic consoles and resistance systems.