After the core exercise when you do the circuit should you have any rest between exercises?
also
instead of doing 4 to 5 sets of each exercise in the circuit could you do 1 set of 4 or 5 different exercises for the same muscle groups or 2 sets of 2 or 3 different exercises. ie instead of doing 4 sets of 6 reps of stiff legged deadlift could you do 2 sets of stiff legged deadlift and 2 of leg curl.