Cameron Josse recently unveiled the results of his case study on heavy resisted sprint training on National Football League players. Josse demonstrated the value of using significantly higher percentages of body mass than many traditional protocols.
Josse is the Director of Sports Performance at DeFranco’s Training Systems. Over the course of four weeks, Josse examined how 20-yard resisted sprints could improve his clients’ 20-yard and 40-yard sprint times.
He first determined the players’ maximum average velocity over 20 yards. Josse used the 1080 Sprint to apply a series of resistances, up to 30 kilograms, to find their V0. He then examined the data in the 1080 Motion web portal to find the load that correlated with 48-52% of each athlete’s V0.
During the subsequent training, Josse manipulated the resistance to keep the athletes’ speed in that range. By week four, three of the four athletes were running 48-52% of their V0 against the maximum resistance the 1080 Sprint can apply: 30 kilograms.
Josse found a differential effect between his linebackers and running backs. All four players improved their relative maximum power. However, the linebackers did so through a greater rise in force while the running backs had a proportionally greater improved in velocity.
Josse’s training also improved the players’ ability to maintain their acceleration over the course of 20 yards. In the early stages of the testing, most of the athletes decelerated in the final five yards. By the last two sessions, though, all were able to at least maintain acceleration – if not increase acceleration – through 20 yards. This demonstrates improvement in their ratio of horizontal-to-vertical force and their ability to minimize decrement.
Cameron Josse demonstrated in the field an emerging trend in sports science research. His athletes saw significant improvement by training against resistance >75% of body mass. This speaks to the effectiveness of sprinting against maximum resistance as a way of improving power output.