Exercise is highly beneficial
Nearly two thirds of UK adults risk their health through insufficient exercise, a survey shows.
The Chartered Society of Physiotherapy polled 2,084 adults, and found 63% admitted to not taking enough exercise.
Lack of exercise and unhealthy living has been linked to greater risk of life threatening illnesses such as cancer, heart disease and stroke.
However, 20% of those questioned said they exercised only once a month or less.
The recommended amount of exercise is one hour every day for children and 30 minutes at least five times a week for adults.
Active people are up to 50% less likely to be at risk of major chronic disease such as coronary heart disease, stroke, diabetes and cancer.
But the survey found only 13% of people knew how much exercise they should be taking - with 56% under-estimating the level.
Over a third (39%) of people said they got out of breath fairly quickly from walking up a flight of stairs. The figure was higher among women (43%) than men (34%).
The most common reason people gave for not taking regular exercise was that they were too busy with work (35%). One in four blamed being tired or unwell.
However, exercise is known to boost performance at work, and counter lethargy, stress and depression.
Over half (53%) of people questioned said that they would take more regular exercise if they could fit it into their existing daily routine, and 39% said it would help if exercise were free.
Bridget Hurley, chartered physiotherapist and spokesperson for the society, said: "Most people know physical activity is good for their health but when it comes to doing it, exercise simply isn't a priority.
"Regular physical activity is as important as eating five portions of fruit and vegetables a day, and people need to understand that you can't keep putting it off."
The Chartered Society of Physiotherapy is launching a new campaign to highlight the importance of exercise in maintaining good health and preventing illness.
It is calling on the NHS and local authorities to widen access to exercise opportunities and invest in popular activities for people of all ages, such as swimming, aerobics classes, gym sessions and cycling.
Ms Hurley said: "Exercise doesn't need to be expensive, boring or time consuming.
"Just going outside at lunchtime for a half-hour walk every day will greatly increase your fitness levels.
"One of the best ways to counteract feeling ill and tired - one of the main reasons people don't exercise - is by becoming more active, which actually gives you more energy."
Dr Ian Campbell, medical director of the charity Weight Concern, said: "The biggest barriers to people being more active are time and expense.
"We need to make activity a normal part of our daily lives.
"And that means making it easier for everyone to be more active, by encouraging walking to work, active lunch breaks, free access to swimming pools and gyms.
"We could achieve so much for health in such a simple way."