Session ratings of perceived exertion (session-RPE) are used to assess global training intensity for team sports. Internal training load can be calculated by multiplying session-RPE by the training session duration. There is little information regarding quantifying training load for protocols designed to improve speed. This is pertinent for field sport athletes (e.g. football players), as speed and acceleration are vital physical attributes. PURPOSE: To determine the intensity of free sprint (FST), resisted sprint (RST), plyometrics (PT) and weights (WT) training programs designed to improve acceleration in field sport athletes by using session-RPE. METHODS: 35 field sport-active men were randomly allocated into 4 groups matched by 10m velocity. Training between protocols was coordinated by duration and progressively overloaded, and involved 2 1-hour sessions per week for 6 weeks. The FST and RST groups used the same program, with the RST group towing a load that caused a 10% velocity drop. The plyometrics and weights programs were matched by similar exercises. Subjects noted session-RPE 30 minutes post-training using the Borg CR-10 scale. RESULTS: Paired samples t-tests found significant (p<=.05) within-group changes in velocity and session-RPE, and one-way ANOVA found significant between-group differences. Each group significantly increased 0-10m velocity by 5-7%, with no differences between groups. Using the Borg CR-10 scale as a reference, the mean session-RPE for the FST group ranged from Somewhat Hard to Hard (4-5); for the RST group from Moderate to Somewhat Hard (3-4); for the PT group from Moderate to Hard (3-5); and for the WT group around Very Hard (7-8). The WT group had significantly higher session-RPE when compared to the FST, RST and PT groups. There were no significant differences in session-RPE between the FST, RST and PT groups. Session-RPE increased over the study period for all groups as training intensified. Conclusion: The results from the current study indicate that session-RPE can assess speed training intensity. Session-RPE is mode-dependent, and acceleration can improve for sprint and plyometrics training at a relatively lower intensity when compared to weights. Nonetheless, the intensity of each protocol was sufficient to improve sprint performance as each group increased 0-10m velocity. Furthermore, the rise in session-RPE across the training period for all groups indicated progressive overload. As there were no significant differences in session-RPE between the FST, RST and PT groups, it can be stated that each mode had a similar intensity. The long recoveries present in sprinting and plyometrics, in conjunction with short activity durations, would contribute to lower session-RPE as the effects of fatigue contributing to perceived exertion are lowered. The nature of strength training (lifting heavy loads near maximum levels) explains why session-RPE for the WT group was greater. However, the primary purpose of weights training is not just to increase running speed; other benefits (e.g. increased sport-specific strength) will also occur. Practical Applications: The session-RPE values recorded from the protocols in this study could be applied when calculating internal training load for periodised training programs for field sport athletes. If speed development is a primary focus, free sprint, resisted sprint and plyometrics training can enhance 0-10m velocity at a relatively lower intensity when compared to weights.
(C) 2011 National Strength and Conditioning Association