Many locomotion tasks, however, require walking a fixed distance rather than for a set time. These measures of walking energetics are based on how much oxygen people consume per unit time. In human walking, net metabolic rate also increases nonlinearly with speed. The energetic cost of walking itself is therefore best understood by subtracting basal metabolic rate from total metabolic rate, yielding Final metabolic rate. However, they also require a continuous basal metabolic rate to maintain normal function. The rate at which an organism expends metabolic energy while walking (gross metabolic rate) increases nonlinearly with increasing speed. Energetics Įnergy minimization is widely considered a primary goal of the central nervous system. Supporting this idea, Darley and Bateson show that individuals who are hurried under experimental conditions are less likely to stop in response to a distraction, and so they arrive at their destination sooner. For example, when walking to catch a bus, the value of the one minute immediately before the bus has departed may be worth 30 minutes of time (the time saved not waiting for the next bus). Everyday situations often change the value of time. This idea is broadly consistent with common intuition. It is plausible that affluence correlates with actual value considerations for time spent walking, and this may explain why people in affluent countries tend to walk more quickly. Levine and Norenzayan (1999) measured preferred walking speeds of urban pedestrians in 31 countries and found that walking speed is positively correlated with the country's per capita GDP and purchasing power parity, as well as with a measure of individualism in the country's society. Economic theory therefore predicts that value-of-time is a key factor influencing preferred walking speed. Conversely, aging, joint pain, instability, incline, metabolic rate and visual decline cause people to walk more slowly.Ĭommonly, individuals place some value on their time. Broadly, increasing value of time, motivation, or metabolic efficiency may cause people to walk more quickly. These are minimized at slower walking speeds. For example, they may trade off time to destination, which is minimized at fast walking speeds, and metabolic rate, muscle force or joint stress. Probably, individuals face a trade-off between the numerous costs associated with different walking speeds, and select a speed which minimizes these costs. People have suggested mechanical, energetic, physiological and psychological factors as contributors to speed selection.
Improving (increasing) people's preferred walking speed is a significant clinical goal in these populations. For example, elderly people or people suffering from osteoarthritis must walk more slowly. Preferred walking speed has important clinical applications as an indicator of mobility and independence. Horses have also demonstrated normal, narrow distributions of preferred walking speed within a given gait, which suggests that the process of speed selection may follow similar patterns across species. Individuals find slower or faster speeds uncomfortable. Many people tend to walk at about 1.42 metres per second (5.1 km/h 3.2 mph 4.7 ft/s). The preferred walking speed is the speed at which humans or animals choose to walk. ( April 2014) ( Learn how and when to remove this template message) Please help improve it to make it understandable to non-experts, without removing the technical details. This article may be too technical for most readers to understand.