Study finds walking and cycling are the route to better health

Couch potatoes take heart. A new study has found that you get more health benefit from moderate activity such as walking than from pumping iron at the gym.

This is great news for all those who feel pangs of guilt as they watch their lycra-clad neighbours rushing off for a heavy weightlifting session or 50 laps at the pool. There is more to be gained by moderate but regular exercise like a brisk walk.

Dr Klaas Westerterp of Maastricht University is the harbinger of this joyous information and shares it with us this morning in a brief communication in the science journal, Nature. He doesn't, unfortunately, include power walking to the pub in his definition of moderate exercise. He does, however, prove, using science and statistics, that regular light exercise such as walking and cycling is a better way to burn off energy than short bursts of intensive exercise.

He decries the fact that very low levels of physical activity are "a pervasive feature of our modern lifestyle". Choosing a sedentary life lounging in front of a TV has left us open to a range of illnesses such as obesity, coronary heart disease and type-2 diabetes.

Curiosity encouraged him to try and discover whether it was better to fight the flab with occasional bouts of very vigorous exercise or to take a gentler route. Provided, of course, subjects could be found willing to tear themselves away from the sofa.

He found 30 healthy, non-obese adults willing to submit to a period of tyranny by undertaking various types of exercise. Total energy expenditure was measured in two ways.

Water tagged with a harmless radioactive isotope provided information about how quickly energy was used up. Dr Westerterp also recorded body movement using portable motion sensors attached to his subjects. These detected motion, or lack of it, throughout the day.

He used this data in combination with activity recorded in diaries and three categories were defined: low intensity, which included lying, sitting and standing; moderate intensity, involving walking and cycling; and high intensity, which included gymnastics, sport and housework. Those working in the home take careful note.

Dr Westerterp concluded that there was little change in the person's total energy expenditure on the basis of time spent on the high-intensity activity, "presumably because this was limited by its nature to being relatively short.

"My results show, however, that the proportion of time distributed between activities of low and moderate intensity is what influences the total energy expenditure and so determines the value of the physical activity level," Dr Westerterp concluded.

People who want to lose weight should exchange low-intensity activities for walking or cycling. Or maybe hiking down to the local.