Fahs, CA, Rossow, LM, and Zourdos, MC. Aanalysis of factors related to back squat concentric velocity. J Strength Cond Res 32(9): 2435-2441, 2018-Measuring bar velocity during barbell exercises can be a useful metric for prescribing resistance training loads and for predicting the 1 repetition maximum (1RM). However, it is not clear whether either anthropometric factors (e.g., limb length) or training experience influences bar velocity. The purpose of this study was to determine the relationships between 1RM back squat bar velocity and femur length, training experience, strength, and 36.6-m sprint time in college athletes. Thirteen college football (22 ± 1 years) and 8 college softball players (20 ± 1 years) performed the 36.6-m sprint followed by a 1RM back squat protocol while average concentric velocity and peak concentric velocity were measured. Height (m), body mass (kg), squat training experience (years), squat frequency (d·wk), and femur length (m) were also measured. Pearson product moment correlations were used to determine the relationship between variables. Average concentric velocity was not related to training age (r = 0.150, p = 0.515), squat frequency (r = 0.254, p = 0.266), femur length (r = 0.002, p = 0.992), or relative strength (r = -0.090, p = 0.699). Peak concentric velocity was related to 36.6-m sprint time (r = -0.612, p = 0.003), relative squat average (r = 0.489, p = 0.029), and relative peak (r = 0.901, p < 0.001) power. These results suggest that college athletes using velocity to regulate squat training may not necessarily need to modify velocity ranges based on limb length or training age. In addition, peak velocity during a 1RM back squat may be a useful indicator of an athlete's relative power output ability and speed. Coaches may consider measuring velocity during strength testing as a surrogate measure for speed and power.