Does a regression equation to predict maximal strength in untrained lifters remain valid when the subjects are technique trained?

This study was implemented to determine if predicting 1 repetition maximum (1RM) bench press strength in untrained lifters from a 7-10RM strength test remains valid when subjects practiced the proper bench press technique. Thirty men 18-26 years of age participated in 2 testing sessions to assess 1RM and 7-10RM bench press strength. The sessions were separated by a minimum of 48 hours. Regression analysis indicated the following equation to predict 1RM strength from weight lifted during the 7-10RM strength test: 1RM = 8.841 + (1.1828*7-10RM). Analysis of predictive accuracy of the regression equation indicated correlation of r = 0.969 (SEE = 4.2 kg or 5.56% of the measured [M] 1RM). Subjects were randomly assigned to an experimental group or a control group. The experimental group practiced proper lifting technique during 4 training sessions during a 2-week period. The control group did not lift weights during this period. Following training, all subjects were reassessed for 1RM and 7-10RM bench press strength. Using the regression equation developed before training, the experimental group demonstrated a correlation of r = 0.983 (SEE = 3.1 kg or 4.2% of M 1RM). The control group demonstrated a correlation of r = 0.989 (SEE = 2.5 kg or 8.8% of the M 1RM). An independent t-test comparing the differences between posttraining bench press scores indicated no significant difference in bench press lifting ability between the experimental group (82.96 kg) following technique training and the control group (75.69 kg). Although the experimental group demonstrated a trend for increased lifting ability following instruction, results suggest that lifting technique does not affect the accuracy of the regression equation to predict 1RM strength.