HR: Why your staff should walk to work

All research has a couple of things that it has to be set against. In this case, the suggestion that previous research that half an hour's exercise daily would result in sufficient activity to keep weight static and a reasonable level of fitness has now been brought into serious question by Physical Activity and Weight Management Research Centre at the University of Pittsburgh.

A study at the Centre tracked the exercise, diet and weight of almost 200 women who, at the start of the process, were clinically obese or overweight. The experiment took in a wide age-range, from 21 - 45, and lasted two years.

The study found that those with clinical obesity would need to take moderate exercise for at least an hour each day before they would begin to see any significant difference in weight loss.

But the participants also restricted their calories - to between 1200 and 1500 daily.

Weight loss was generally slow but sustainable - for some. Those that lost 10% of their body weight were exercising for an average of 68 minutes per weeekday plus additional random exercises as instructed by the Centre.

Most of the women lost that 10% in the first six months. But then it began to return. The Centre found that one of the biggest problems was that the subjects were often unreliable in their exercise patterns, despite evidence that exercise was demonstrated to have more impact on weight loss than any other factor, including diet.

Hidden in the figures is an interesting thing: those who lost the most were also those who added the highest proportion of exercise: they increased their exercise by 55 minutes, and so were doing less than 15 minutes per day previously.

The Centre says that there is a direct correlation between the amount of exercise done and the amount of weight lost.

And the type of exercise was interesting: no gym or shaping/toning - simple, basic cardio-vascular exercise was best.

So, the old arguments to use the stairs not the lift, to park at the far side of the car park, to get off the bus a stop early and walk to the office are demonstrated as being the ideal way to begin. And if you walk half an hour to work and half an hour back, you'll get your exercise in by accident with remarkably little additional time spent, and cost free.

Somewhat startling in the Centre's report is that doing 68 minutes per day five days per week burns remarkably few calories: under 1900.