Shortly after a baby turns one years old, he or she begins to crawl, toddle along and eventually walk.

London - The average toddler covers more than two and a half miles a day (around 4km), researchers say – a distance that would put many adults to shame.

Their mini marathon involves 14,208 steps and, less surprisingly, 102 falls.

Researchers videoed more than 130 infants aged 12 to 19 months as they explored a specially-designed playroom. A further 15 infants were taped at home.

Some were “expert crawlers” who had yet to start to walk, some had just taken their first steps and a few had been toddling for months.

The walkers clocked up an average of 2,368 steps or 0.44 miles in an hour, falling 17 times. The new walkers had the most falls, with one managing 69 an hour.

The researchers, from New York University, calculated that if toddlers are active half of the time they are awake, they average 2.6 miles a day. Figures for children in the playroom were similar to those at home, meaning the totals could not be explained by excitement at the sight of new toys.

They also compared 12-month-old crawlers and walkers to establish why they start to walk when they can get around on all fours.

Writing in the journal Psychological Science, Professor Karen Adolph, a psychologist specialising in infant learning, said this was because although they fell more when walking, they moved further and faster.

While the number of steps taken may seem high, estimates for other new skills are “equally enormous”, she said, as middle-class infants hear 2,150 words an hour. - Daily Mail