The short answer, Kmac, to ‘Can you discount calories burned that day?’ is ‘No’ – Why put in two lots of effort (fasting and exercising) only to have them cancelled out by eating more? Part of the plan, I believe, is to re-train one’s appetite.

See one of Michael M’s early comments on exercise at: http://thefastdiet.co.uk/intermittent-fasting-and-exercise/

Also, from the ‘faq’ list, top-right of page: ‘Can I exercise on a fast day?
There is good evidence that people who exercise in the fasted state burn more fat. In one study men who exercised before breakfast burnt more fat than those who exercised afterwards. Exercise can also be a useful distraction if you begin feeling peckish. Don’t, however, attempt to do a lot of endurance training on a fasting day and if you feel uncomfortable, stop.’