The 5:2 plan - question re: exercise

Hi all,

For those of you 'in the know' about the 5:2 plan, or alternate fasting - do you eat back your exercise calories? I plan on going for a moderate run tonight (I feel fine on fasting days, I wouldn't exercise otherwise!), and I slipped up and had 4 squares of chocolate this morning so I won't quite have enough for tea otherwise, hehe - thoughts/comments on eating back exercise cals on fasting days?

Thanks guys!