The Government suggests healthy adults should do a minimum of 30 minutes moderate-intensity physical activity, five days per week.These don't necessarily have to all be in one go; you can spread them out if you wish. Walking is perfect for fulfilling this requirement - just walking to the shops counts, though this guideline suggests moderate activity so bear that in mind.

If you are obese, or have a medical condition that means you need to manage your weight, 45-60 minutes is recommended.

Deaths resulting from low physical activity are now responsible for over two million deaths per year worldwide, with one in five people in England now considered obese.

Frequent moderate exercise

• Routine and regular moderate activity may actually be more beneficial than short bursts of intense activity (Westerterp 2001).
• A brisk one-mile walk in 20 minutes burns around 100 calories - as much as swimming for 10 minutes, playing football for 12 minutes or doing aerobics for 16 minutes.
• Gym membership has increased every year since the early 1980s but obesity and other problems related to lack of physical activity have continued to rise (Guardian 28 October 2003).
• Most people find regular, moderate exercise is easier to build into a busy lifestyle in a sustainable way, requiring much less motivation and commitment than more demanding activities.
• Exercising for ten minutes three times a day is as beneficial as exercising for 30 minutes once a day (Murphy and Hardman 1998)