Following the collection of baseline data, all participants will attend a 1 hour education session during which they will receive a presentation outlining: the health problems associated with prolonged sedentary behaviour; how much sitting is recommended; feedback on their own baseline sitting behaviour; and tips on how to reduce and break up sedentary behaviour. They will be given a summary of their baseline activity data . Group 1 will then return to work as normal. Group 2 will receive an excel file to upload to Microsoft Outlook which will deliver prompts to break sitting at random times, once within an hour. The prompts will run for a period of 10 weeks and their content will be the same brief, positively framed messages that were evaluated favourably by participants in the pilot project. Measurements for all participants will be repeated as follows: Questionnaires Q2 and Q3 will be repeated after the education session and at 12 week follow-up; 1 week of activity monitoring will be repeated between weeks 2-4 of the intervention period, 8-10 of the intervention period, and at 12 week follow up.