A major reason why coaches want to make their athletes stronger is because strength underpins performance in numerous athletic movement skills such as running, jumping and change of direction. Essentially, the more force an athlete can produce into the ground, the better. There is also increasing evidence to suggest that stronger athletes are less likely to experience an injury. Furthermore, recent research in rugby players (reviewed in a previous blog post) demonstrated that stronger players recovered faster compared to weaker players following competitions. Less studied however is the potential relationship between strength and reactive ability. Do stronger athletes possess greater reactive ability than weaker athletes?
A new study published ahead of print in the International Journal of Sports Physiology and Performance investigated the relationship between maximal isometric strength and reactive ability in athletic individuals. The sample included a total of 45 collegiate athletes (~23 years of age) that were recruited from a variety of sports teams. Peak force derived from an isometric mid-thigh pull on force plates and the reactive strength index calculated from drop jumps off of 0.3, 0.4, 0.5 and 0.6 m boxes was assessed for each subject. In addition to performing correlational analyses, the researchers evaluated differences in reactive ability among the sample based on relative strength.
The results showed that there were significant moderate relationships found between absolute, relative and allomertically scaled peak force (i.e., maximum strength) and the reactive strength index from each box height. After categorizing the sample based on relative strength into “stronger” (n = 11) and “weaker” (n = 11) groups, the researchers found that the stronger group demonstrated a significantly larger reactive strength index compared to the weaker group. In addition, the weaker athletes showed significant decrements in their reactive strength index as eccentric stretch loads increased with the higher box heights. This was in contrast to the stronger athletes who were able to maintain their performance as box height increased. Therefore, the authors conclude that reactive strength may be dictated by relative maximal strength, but particularly eccentric strength.
Beattie, K., Carson, B. P., Lyons, M., & Kenny, I. C. (2016). The Relationship between Maximal-Strength and Reactive-Strength. International Journal of Sports Physiology and Performance, In Press.