Document Type



Through recent advances in smartphone technology, two mobile applications (apps), LizaPlus and PowerLift, have been developed to monitor strength training and predict 1RM based on maximal concentric velocity during submaximal exercises. The aim of this study was to assess the validity of the two apps to predict 1RM using the bench press exercise. Strong correlations were found between actual 1RM and predicted 1RM values (r-values: 0.80 to 0.86, p < 0.001). Bland and Altman plots show a systematic bias such that predicted 1RMs tend to be higher than actual 1RM for both apps. Results indicate both apps are valid in predicting 1RM but there appears to be systematic bias to overestimate actual 1RM. Caution should be used when basing training loads on these predicted 1RM values as there is an increased risk of injury through prescription of excessive training load.