Validation of Individual Calibration Procedure in Prediction of One Repetition Maximum in Bench Press

In literature various studies about application of accelerometer sensors in analysis of weight lifting performance can be found. One specific application is prediction of one repetition maximum (1-RM) from submaximal lift, where the 1-RM is estimated on the basis of submaximal weight and acceleration values occuring during the lift. The prediction accuracy has been found to be good at a large subject group level. However, differences between individual subjects may result in inaccurate prediction in occasional cases. Therefore utilization of anthropometric data or information of weight lifting experience of the individual could improve the accuracy of the prediction. To evaluate this, in this study individual calibration of the prediction algorithm was evaluated in case of accelerometer based 1-RM prediction in bench press. The calibration procedure was tested with a total of 30 subjects (15 females, 15 males). The data analysis showed excellent correlation coefficient R of 0,99 (p<0,001) between the predicted 1-RM and the actual 1-RM in the validation phase of the study. Relative absolute error of 1-RM was 4,6 % for bench press. Without use individual calibration the correlation coefficient would have been 0,99 (p<0,001) and the relative absolute error would have been 9,2 %. The results clearly show the individual calibration increase significantly the 1-RM prediction accuracy.