A type of physical training that usually involves carrying out a number of different exercises in a repetitive order.
There are many different types of circuit training but the basic circuit comprises of a number of "Stations". At each station a different physical activity is performed (Such as press ups, sit ups, weight lifts, shuttles and so on). A person begins at one station and performs that activity until ready to move on to the next one, whereupon they commence the activity for the new station and so on until they come back to the original station they started at and the circuit then repeats or finishes. The criteria for completing and moving from station to station can be either time based (I.e. Two minutes activity on each), exertion (I.e. once having completed 25 press ups) or simply once told to move on.
Circuits are often considered a favourable form of PT when the rain is coming down so hard your flinching or it is so cold you've lost all feeling in your toes, particularly at training establishments where PT sessions are mostly mandatory.