Want to feel happier at work? Take a five-minute walk

Lead researcher Keith Diaz told BBC News that most adults now spend three-quarters of their waking day sedentary.

While general advice to "sit less and move more" is correct, people need to know what dose, he added.

"The good news is that a walk break every hour for five minutes is enough to improve mood and lower fatigue. And people found this realistic and attainable," Diaz said.

The study by Columbia University surveyed more than 11,000 US employees - most of them in office jobs and working eight- to nine-hour shifts.

For the first week, they went about their usual routine and completed daily surveys about tiredness, their mood, and work performance.

For the following two weeks they were asked to take walking breaks at work of five minutes every half hour, every hour or every two hours and fill out similar surveys.

A walk every half hour was beneficial for mood and reducing tiredness, but was disruptive to the day job. One every two hours was better than no walking, but researchers found a five-minute stroll each hour led to the biggest and most feasible improvement in productivity, mood and alertness.