Circuit Training and Exercise Drills - Types of circuits

The two basic types of circuits are the free circuit and the fixed circuit. Each has distinct advantages.

Free Circuit
In a free circuit, there is no set time for staying at each station, and no signal is given to move from one station to the next. Soldiers work at their own pace, doing a fixed number of repetitions at each station. Progress is measured by the time needed to complete a circuit. Because soldiers may do incomplete or fewer repetitions than called for to reduce this time, the quality and number of the repetitions done should be monitored. Aside from this, the free circuit requires little supervision.

Fixed Circuit
In a fixed circuit, a specific length of time is set for each station. The time is monitored with a stopwatch, and soldiers rotate through the stations on command.
There are three basic ways to increase the intensity or difficulty of a fixed circuit:
Keep the time for completion the same, but increase the number of repetitions.
Increase the time per station along with the number of repetitions.
Increase the number of times soldiers go through the circuit.