Utilizing Force-Velocity Profiles to Improve Athletic Performance in American Football Players

Abstract

Introduction: American football requires strength, power, and speed. Force-velocity (FV) profiling describes the relationship between muscular force production and contraction velocity, and when multiplied together, the resulting product is power. FV profiling uses loaded jumps in the vertical plane and running speed in the horizontal direction to predict the imbalance between velocity and force development. Purpose: The first purpose of this study was to determine if FV profiling and optimized training improves performance metrics in American collegiate football players (i.e., countermovement vertical jump (CMJ), flying 10’s sprinting speed, 1-repetition maximum (1-RM) barbell back squat, 1-RM power clean). The second purpose was to determine if a 6-week optimized training regimen would correct FV imbalances. Methods: Eighty-two male, division-I collegiate American football athletes (20.7 ± 1.5 years old) provided written informed consent to participate in this study. Subjects were grouped by their position (i.e., offense or defense). Each subject participated in unloaded and loaded squat jumps (for vertical FV profiling) and unloaded sprints (for horizontal FV profiling). The following day, sprinting speed during a flying 10 and a full clean 1-repetition maximum (1-RM) were measured. Either 24 or 48 hours later, 2 additional performance metrics were measured: CMJ and a 1-RM back squat. Results: Of the 82 football players enrolled in the study, 50 subjects completed the protocol. The vertical FV profiling revealed that 9 athletes were velocity-deficient, 16 athletes were well-balanced, and 25 athletes were force-deficient. Descriptive statistics showed that the %FV imbalance of the velocity- and force-deficient groups decreased or increased, respectively, and each group’s imbalance moved toward the well-balanced category (90-110%). Results indicate that %FV imbalances improved as a result of the training in the velocity- and force-deficient groups, and the well-balanced group retained its well-balanced standing. Conclusion: Six weeks of individualized training was sufficient to improve performance metrics in collegiate American football players and notably, correct FV imbalances. Utilization of FV profiling catered to the individual needs of athletes as opposed to a one-size-fits-all approach, where all athletes utilize the same training program.