This study aimed (1) to analyze the accuracy of mean propulsive velocity to predict the percentage of the 1-repetition maximum in the seated military press exercise and (2) to test the effect of gender and of a resistance training program on the load-velocity profile. The load-velocity relationships of 26 men and 13 women were evaluated by means of an incremental loading test up to the individual 1-repetition maximum. Additionally, the load-velocity relationships of 24 of those 26 men were measured again after a six-week resistance training program. Individual load-velocity relationships had very high coefficients of determination and low standard errors of the estimate (R-2=0.987; standard error of the estimate=0.04m/s). Differences higher than 10% between the individual and the general load-velocity profiles as well as a high between-participants' variability for the mean propulsive velocity attained at each 1-repetition maximum (coefficient of variation=12.9-24.6%) were identified. The load-velocity profiles proved to be affected by both the gender (higher mean propulsive velocity at each %1-repetition maximum for men) and the resistance training program (lower mean propulsive velocity at each %1-repetition maximum after training). Taken together, these results speak in favor of creating individual profiles instead of using general equations when using the load-velocity relationship to estimate relative load.