Employees who spend half of an eight-hour working day standing use 13% more energy than colleagues who are seated, says a new study. Researcher David Dunstan measured the energy expenditure of 20 desk-based workers over two weeks while standing and sitting at work. During an average fiveday working week, the extra energy used standing for four hours a day equated to a 45-minute brisk walk.
   Much of the extra energy use came from the contraction of muscles used to keep the body upright. Recent research found people who spend most of their days sitting — at work, on the bus or train and while watching TV — may not ward off heart disease, even if they exercise for 30 minutes a day as recommended. Workers who don't have heightadjustable workstations should take a break, stand up and move every 20 to 30 minutes.
   ANI