To use the minimum effective dose or maximum tolerable dose of training with athletes remains a topic of debate among sports coaches. One may argue that aiming for the minimum effective dose of a given training parameter (i.e., plyometric training) will create more time for technical and tactical training, of which usually takes priority from a coaches perspective. In contrast, the maximum tolerable dose of training will take longer to complete and thus leave less time for technical and tactical work. Regardless of which side of the debate one favors, it would be useful for all coaches to be aware of the dose response relationship for a given training modality. Considerable research has investigated the dose response relationship with resistance training while comparably less research has been done with plyometrics.
A new study published ahead of print in the Journal of Strength and Conditioning Research evaluated the performance effects of high volume versus low volume plyometric training in rugby players. A group of 36 collegiate male rugby players were evenly and randomly separated into a high volume group, a low volume group and a control group. Before and after a 6-week training program measures of reactive strength index (jump height divided by ground contact time) and leg stiffness were acquired from jump testing on a force plate for all participants. The training intervention involved 2 plyometric sessions per week separated by 48 hours. The sessions consisted of various plyometric exercises including drop jumps, lateral and horizontal jumps, hurdle jumps and bounds. The exercise selection, sequence and rest-periods were matched among groups but total volume (foot contacts) varied. Total foot contacts were 480 and 1920 for the low and high volume groups, respectively.
The results showed a significant group x time interaction effect for reactive strength index. Both the high volume and low volume groups similarly and significantly improved their reactive strength index (effect sizes ranging from small to moderate) compared with the control group. Measures of leg stiffness did not statistically change for any group. These findings have demonstrated that the low volume group improved reactive strength to similar levels as the high volume group despite having performed 75% less volume. This suggests that considerably less time and effort can be spent on plyometric training during practices which can leave more time for technical and tactical work.
Jeffreys, MM. et al. The effect of varying plyometric volume on stretch-shortening cycle capability in collegiate male rugby players. Journal of Strength and Conditioning Research, In press.