1000 calorie workout

Hi, I did my first 1000 calorie workout for day 26 of FB fit and I’ve woken up feeling battered all over and also really dehydrated, I’m guessing I need to eat and drink more after I work out but it hard because I have to do it in the evening after my little one with additional needs is in bed. How has anyone else felt after these intense sessions.? I’m loving the programme, down a dress size already in just four weeks and feel much more focused and alive all over, thanks