The first successful robots to walk had six legs. As technology has improved, robots can now walk on two legs, though they still do not walk as gracefully as humans.
The best way to lose weight by walking is to take a longer, moderately paced walk (40 minutes at 60-65% maximum heart rate). Shorter, faster walks (20-25 minutes at 75%-85% maximum heart rate) are best for conditioning the heart and lungs.
A 150-pound man burns 100 calories per mile walking. A 200-pound man burns 133 calories per walking mile. And a 250-pound man burns 166 calories per mile. A person burns essentially the same amount of calories whether they run or walk a mile. Running just gets a person to a destination faster.
A significant difference between walking and running is the amount of time each foot contacts the ground. While walking, at least one foot is in contact with the ground at any given time, and the length of time the foot is in contact is longer than while running. During a run, foot contact with the ground is less than walking, and there is a period of time where both feet are not in contact with the ground.
Chickens, pigeons, cranes, quails, and at least eight of the 27 families of birds bob their head when they walk. Researchers suggest that they do this because head bobbing helps with balance, provides depth perception, and sharpens their vision.
Walking can help decrease the risk of heart attack, decrease the risk of developing type 2 diabetes and can even reduce the risk of bone fracture. Additionally, brisk walking can reduce stress and depression levels as well as improve cancer survival rates.
In 2009 the National Household Travel Survey reported there are an estimated 42 billion walking trips nationwide every year. Americans take a total of about 388 billion annual trips. Walking, then, makes up roughly 10.9 % of all trips.
Younger people walk dramatically more than older age groups. Five 15-year-olds have almost twice the percentage of the walking trips as the 40-to-64-year-old age group (15.2 and 7.8%, respectively).
Less than 50% of American adults exercise enough to gain significant health or benefits. Inactivity is the second leading cause of preventable death in the U.S., second only to tobacco use.