YES! You can maintain a level of regular activity during your programme. Your coordinator will have assessed your lifestyle during your consultation and will ensure that you have the correct amount of juices to suit your levels of exertion. Do remember though that all of the hard work is being done on the inside so just enjoy relaxing and getting fit without feeling the need to pound the gym.
You may feel that at times you could easily tackle a marathon but you may find that sometimes enthusiasm outweighs stamina.