In walking the body 'vaults' over the leg on the ground, raising the center of mass to its highest point as the leg passes the vertical, and dropping it to the lowest as the legs are spread apart. Essentially kinetic energy of forward motion is constantly being traded for a rise in potential energy. This is reversed in running where the center of mass is at its lowest as the leg is vertical. This is because the impact of landing from the ballistic phase is adsorbed by bending the leg and consequently storing energy in muscles and tendons. In running there is a conversion between kinetic, potential, and elastic energy.There is an absolute limit on an individual's speed of walking (without special techniques such as those employed in speed walking) due to the velocity at which the center of mass rises or falls - if it's greater than the acceleration due to gravity the person will become airborne as they vault over the leg on the ground. Typically however, animals switch to a run at a lower speed than this due to energy efficiencies.

As a leisure activity: Race walkingMany people walk as a hobby, and in our post-industrial age it is often enjoyed as one of the best forms of exerciseFitness walkers and others may use a pedometer to count their steps. The types of walking include bushwalking, racewalking, weight-walking, hillwalking, volksmarching, Nordic walking and hiking on long-distance paths. Sometimes people prefer to walk indoors using a treadmill. In some countries walking as a hobby is known as hiking (the typical North American term), rambling (a somewhat dated British expression, but remaining in use because it is enshrined in the title of the important Ramblers' Association), or tramping. Hiking is a subtype of walking, generally used to mean walking in nature areas on specially designated routes or trails, as opposed to in urban environments; however, hiking can also refer to any long-distance walk. More obscure terms for walking include "to go by Marrow-bone stage", "to take one's daily constitutional", "to ride Shank's pony", "to ride Shank's mare", or "to go by Walker's bus.

" Among search and rescue responders, those responders who walk (rather than ride, drive, fly, climb, or sit in a communications trailer) often are known as "ground pounders".The world's largest registration walking event is the International Four Days Marches Nijmegen. The annual Labor Day walk on Mackinac Bridge draws over sixty thousand participants. The Chesapeake Bay Bridge walk annually draws over fifty thousand participants. Walks are often organized as charity events with walkers seeking sponsors to raise money for a specific cause. Charity walks range in length from two mile (3 km) or five km walks to as far as fifty miles (eighty km). The MS Challenge Walk is an example of a fifty mile walk which raises money to fight multiple sclerosis. The Oxfam Trailwalker is a one hundred km event. Sheep walking along a roadIn Britain, the Ramblers' Association is the biggest organisation that looks after the interests of walkers. A registered charity, it has 139 000 members. Regular, brisk cycling or walking can improve confidence, stamina, energy, weight control, life expectancy and reduce stress.

It can also reduce the risk of coronary heart disease, strokes, diabetes, high blood pressure, bowel cancer and osteoporosis. Modern scientific studies have showed that walking, besides its physical benefits, is also beneficial for the mind — improving memory skills, learning ability, concentration and abstract reasoning, besides reducing stress and uplifting ones' spirits.
 

Walking

Walking (also called ambulation) is the main form of animal locomotion on land, distinguished from running and crawling. When carried out in shallow waters, it is usually described as wading and when performed over a steeply rising object or an obstacle it becomes scrambling or climbing. The word walk is descended from the Old English wealcan "to roll".Walking is generally distinguished from running in that only one foot at a time leaves contact with the ground: for humans and other bipeds running begins when both feet are off the ground with each step. (This distinction has the status of a formal requirement in competitive walking events, often resulting in disqualification even at the Olympic level.) For horses and other quadrupedal species, the running gaits may be numerous, and walking keeps three feet at a time on the ground.The average human child achieves independent walking ability between nine and fifteen months old.While not strictly bipedal, several primarily bipedal human gaits (where the long bones of the arms support at most a small fraction of the body's weight) are generally regarded as variants of walking.

These include:Hand walking; an unusual form of locomotion, in which the walker moves primarily using their hands. walking on crutches (usually executed by alternating between standing on both legs, and rocking forward "on the crutches" (i.e., supported under the armpits by them); walking with one or two walking stick(s) or trekking poles (reducing the load on one or both legs, or supplementing the body's normal balancing mechanisms by also pushing against the ground through at least one arm that holds a long object); walking while holding on to a walker, a framework to aid with balance; and scrambling, using the arms (and hands or some other extension to the arms) not just as a backup to normal balance, but, as when walking on talus, to achieve states of balance that would be impossible or unstable when supported solely by the legs. For humans, walking is the main form of transportation without a vehicle or riding animal. An average walking speed is about 4 to 5 km/h (2 to 3 mph), although this depends heavily on factors such as height, weight, age and terrain.

A pedestrian is a walking person, in particular on a road (if available on the sidewalk/path/pavement). Biomechanics:Human walking is accomplished with a strategy called the double pendulum. During forward motion, the leg that leaves the ground swings forward from the hip. This sweep is the first pendulum. Then the leg strikes the ground with the heel and rolls through to the toe in a motion described as an inverted pendulum. The motion of the two legs is coordinated so that one foot or the other is always in contact with the ground. The process of walking recovers approximately sixty per cent of the energy used due to pendulum dynamics and ground reaction force.Walking differs from a running gait in a number of ways. The most obvious is that during walking one leg always stays on the ground while the other is swinging. In running there is typically a ballistic phase where the runner is airborne with both feet in the air (for bipedals).Another difference concerns the movement of the center of mass of the body.