Gyms are good for you… or bad for you, depending on which week it is, which newspaper you read, or which celebrity is launching a new fitness book.

So perhaps the best principle is to follow the formal advice of the Government’s Chief Medical Officer, Sir Liam Donaldson, who has pulled no punches in warning that much of the British public is becoming obese at an alarming rate.

The consequences of obesity and a lack of fitness are far more complicated than just a spare tyre around the middle. The real effect is a genuine threat to your life, and the cost of physical inactivity in England – including treatment for lifestyle-related diseases and sickness absence – is estimated at £8.2 billion a year.

Fat Facts

While smoking and an unhealthy diet have long been regarded as factors in chronic disease, it is now clear that exercise – or rather the lack of it – is equally important, particularly for youngsters who have become used to fast food and long evenings in front of the TV or PC screen.

Physical activity is now associated with a reduction in the overall risk of cancer. There is a marked protective effect on against colon cancer. The most active individuals have, on average, a 40 to 50 per cent lower risk than the least active. Physical activity is also associated with a reduced risk of breast cancer among post-menopausal women, and possibly also to a reduction in risk of lung cancer.

• About two thirds of men and three-quarters of women do less than 30 minutes’ of moderate intensity activity a day on at least five days per week.
• Seven in ten boys and six in ten girls aged two to 15 achieve at least 60 minutes’ physical activity each day of the week. However, two in ten boys and girls are active for less than 30 minutes per day.
• Obesity levels in England are high and rising. Almost a quarter of adults and about 16% of two to 15 year olds are obese.

What is the right amount of exercise?

For general health benefit, adults should achieve a total of at least 30 minutes a day of, at least, moderate intensity physical activity, on five or more days of the week. But it doesn’t have to be all done in one go.

The recommended levels of activity can be achieved either by doing all the daily activity in one session or through shorter bouts of activity of ten minutes or more.

Moderate physical activity should cause heart and breathing rates to increase. It may lead to sweating. However, it is not overly tiring - you should be able to continue for quite a while.

For example, an adult may take a daily brisk walk or cycle to work and children could be encouraged to walk to school, in addition to two or three weekly leisure activities such as swimming, football, or gym. All activity can help prevent obesity, so people should make the most of all small opportunities to be active such as using stairs and doing the gardening.

According to Sir Liam Donaldson, "People need to stay active over the whole of their lives if they are to stave off the threat of obesity and killer diseases like cardiovascular disease, type II diabetes and cancer,”

"It is not about spending hours and hours in the gym, but it is about finding ways to build activities into our daily lives.”

Changing the way we live

The government’s plans for improved health will mean a quantum shift in the way we look at exercise. It also puts an obligation on the government to build an environment that supports people in more active lifestyles (coincidentally solving congestion issues).

“Physical activity needs to be seen as an opportunity for enjoyment, for improved vitality, for a sense of achievement, for fitness, for optimal weight, and for health,” says the official report.

The change the government is initiating is expected in all areas of the country and will take years to deliver.

• Regional physical activity plans are to be developed by Regional Sports Boards, leisure services, transport planners and providers, regional development agencies and industry.
• Local transport plans are to give particular consideration to walking and cycling as means of commuting and personal travel.
• Local authorities are to take steps to make neighbourhoods and communities more ‘activity friendly.’
• Town planners, architects and engineers are to ensure that physical activity is facilitated in new buildings, streets, housing developments and schools.
• Leisure services are to find ways of encouraging people to try new activities.
• Schools and colleges are to encourage children and young people of all abilities to take part in sports. They will also support walking to school and college.
• Employers are to encourage active travel to work; to ensure facilities, such as showers or secure cycle storage, are available; to provide opportunities for activity breaks for their staff, and to encourage use of stairs.