A two-arm parallel randomised controlled trial comparing pedometer-based intervention with and without email counselling in a primary care setting. Physically inactive patients from four general practices will be randomised to the pedometer-plus-email group or to the pedometer-alone group. All patients will be instructed to gradually increase the daily number of steps to at least 10,000. Patients in the pedometer-plus-email group will receive 8 counselling emails based on behavioural techniques. The primary outcome will be change in average daily steps measured during 7-day period at baseline and at 12 weeks.

Inclusion Criteria:

• physically inactive, i.e. takes less than 8,000 steps per day at baseline
• registered at the participating general practice,
• over 18 years of age,
• regular email user, and willing to use email for the purpose of the study,
• has a home computer with access to the Internet.

Exclusion Criteria:

• medical or psychiatric condition which the general practitioner considers as inappropriate for participating in the intervention (e.g., terminal illness, psychotic illness, chronic disorders or diseases that seriously influence the ability to be physically active, dementia or significant cognitive impairment, unable to move about independently),
• medical, personal of family condition which the general practitioner considers temporarily affects mean daily step count at baseline (e.g., acute illness, holiday or business trip),
• pregnant woman,
• currently engaging in regular sports or exercise (at least twice a week),
• failure to upload pedometer data to a website at baseline assessment,
• failure to give informed consent with the study.