An expert has claimed that standing for three hours per day is as good for you as doing 10 marathons a year. Dr Mike Loosemore, Lead Consultant in Exercise Medicine at the Institute of Sport, Exercise and Health, said that official guidelines on exercise are impractical and can seem an impossible task for many people. So instead of doing your daily tasks such as emails, phone calls etc seated why not get up and stand for them. If it is hard for you to find time to exercise in a day then walking to work or the shops instead of driving are other ways to ensure you get enough 'standing time' in your day.
Reference - Daily Mail - http://www.dailymail.co.uk/health/article-2663889/Standing-three-hours-day-health-benefits-10-marathons-says-leading-doctor.html