The effect of a 12-over spell on fast bowling technique in cricket.

Nine members of the Western Australian Cricket Association fast bowling development squad were selected to determine the effects that a 12-over spell would have on fast bowling technique and selected physiological variables. Three high-speed cameras operating at 100 Hz filmed the subjects bowling the 5th and 6th balls of their 1st, 6th, 10th and 12th overs. Blood lactate and heart rate were recorded and the bowlers were shown to work at between 80.3% (1st over) to 84.7% (12th over) of their maximum heart rate during the 12-over bowling spell. Data from the 5th and 6th deliveries from each over were averaged to provide representative data, as no significant differences were evident between these two deliveries for the selected kinematic variables. For all subjects, no significant differences were recorded for the selected kinematic variables throughout the duration of the 12-over spell, indicating that in general fast bowling technique does not change over this length of spell. In addition, there was some evidence of change in technique for the bowlers who used a front-on action, where counter-rotation of the shoulders was found to increase; however, this could only be confirmed by a more comprehensive study.