If you haven’t exercised for a while or haven’t done any circuit training type exercise before then you might be a little bit sore after the workout. Some people feel the soreness 24 hrs, 48 hrs or 72 hrs after the workout. It’s known as Delayed Onset of Muscle Soreness (DOMs) and is the sign of a good workout but shouldn’t be unbearably painful. After doing a few boot camps your body will become more used to the exercises and the soreness will become less and less as you become fitter.