A brisk 30-minute walk five days a week is more effective than any other form of exercise for keeping weight down, a major study has concluded.
The benefits of “high impact” walking outweigh those from keep-fit activities including running, swimming and working out at the gym, according to researchers at the London School of Economics and Political Science. Walkers need to go quickly enough to raise the heart rate and prompt a sweat.
The effects were particularly strong for women of all ages, with those walking regularly for half an hour found to be about a dress size smaller than average, losing 4.3cm (1.7in) off the waist. The figure was 3.3cm (1.3in) for men. Men and women over the age of 50 also experienced stronger benefits than younger counterparts. Scientists believe that, because humans have been walking upright for four million years, it is a more natural behaviourthat may tap into biological mechanisms that reduce the risk of obesity. Previous research has shown that walking can reduce the risk of heart disease, high blood pressure, high cholesterol and diabetes more effectively than running.
Grace Lordan, who led the latest research, said that it was hard to gauge whether exercise in a gym was consistently at a high enough intensity.
Experts have also suggested that calorie burning is optimised when walking because it is a constant, uninterrupted activity — unlike a game of tennis where play might be stop-start.
Dr Lordan said: “When it comes to walking, you can’t really be doing it wrong. You need to be out of breath and slightly red in the face.” Alternatively, the advantage may simply be that people are more likely to stick with walking as a long-term habit, she said.
Almost 50,000 people took part in the annual Health Survey for England between 1999 and 2012. They filled in a questionnaire and were visited by a nurse who took measurements including their body mass index (BMI), a figure derived by combining weight and height, and waist circumference.
Men who walked briskly for 30 minutes five days a week for four weeks had a BMI one unit lower than average. For women the difference was 1.8 units.
While exercise or participation in sport for the same amount of time was also effective at keeping weight down, the results were less marked, with men having a BMI 0.3 units lower than average and women about one unit lower.
One in four British adults is obese, defined as having a BMI of over 30. It is estimated that almost 80 per cent of the population is failing to meet government activity guidelines, costing the NHS almost £1 billion a year.
Activities compared with walking in the study were swimming, cycling, working out at a gym, dancing, running, jogging, football, rugby and squash, as well as exercises such as press-ups or sit-ups. It also looked at the impact of heavy housework, such as moving furniture, walking with heavy shopping and scrubbing floors, and heavy manual activities, such as digging, felling trees, chopping wood and moving heavy loads.
Dr Lordan wrote in the journal Risk Analysis: “Given the obesity epidemic and the fact that a large proportion of people in the UK are inactive, recommending that people walk briskly more often is a cheap and easy policy option.”
A campaign to promote walking might be less controversial than a tax on sugary products, she added.
Best foot forward
You can tell if you’ve reached “moderate intensity” exercise if you can talk, but are unable to sing the words to a song.
You shouldn’t exercise for two to three hours after a heavy meal, but a small, non-sugary snack like a banana before you begin can help keep energy levels up.
If you start slow and gradually increase your pace, your muscles will be warmer and more efficient by the time you’re full-steam ahead.
It is important to drink water if you’ll be out doing any exercise that lasts more than 30 minutes.
The NHS recommends topping up aerobic activity like walking with two days of strength exercises that work all the major muscles.