Abstract: A training system (10) has a number of motion detection units (12) which are triggered in sequence. Each motion detection unit (12) has a radar transmitter (26) for transmitting a radar beam (34), a radar receiver (28) and an indicator in the form of LED lamps (18) and a buzzer (20). A control system (13) triggers each motion detection unit (12) according to a sequence to activate the LED lamps (18) and a buzzer (20). The sequence simulates a game or a training exercise, or may be randomly generated. The motion detection units (12) are operable to de-activate the indicators when the radar receiver (28) detects a radar reflection from an object passing through the radar beam (34).