A key performance indicator is a convenient performance test that strongly correlates with one or more on-field performance variables. In the case of team-sport athlete’s, it would be useful to have a key performance indicator for common actions during play such as accelerating or sprinting, jumping and change of direction. The majority of research investigating relationships between potential key performance indicators has been conducted predominantly with male athletes, leaving female athletes largely underrepresented. It is therefore less clear how traditional key performance indicators such as strength and various vertical jump tests relate with on-field performance variables among female athletes. Coaches can track key performance indicators over time to determine how their athletes are adapting to training and may serve as useful markers of readiness and acute fatigue.
A new study published ahead of print in the International Journal of Sports Physiology and Performance aimed to determine the relationship between potential key performance indicators and on-field performance variables in female team-sport athletes. A group of 26 female athletes (~16 years of age) were recruited for the study and were tested in the isometric mid-thigh pull, vertical jumping, 10-m sprint speed and change of direction speed (5-0-5 test). The data was analyzed in two ways: 1) with bivariate correlations to determine the magnitude of the relationship among variables and 2) by comparing groups based on maximal strength to determine if female athletes with greater strength also displayed greater performance in jumping, sprinting and change of direction.
The results showed that maximal strength derived from the isometric mid-thigh pull test displayed significant moderate to strong relationships with 10-m sprint time and 5-0-5 change of direction speed. Vertical jump tests (i.e., squat-jump and countermovement-jump) were strongly correlated with 10-m sprint time and change of direction speed from the 5-0-5 test. After splitting up the group into high and low levels of strength, it was found that stronger athletes demonstrated significantly faster sprint and change of direction times as well as greater vertical jump height compared with weaker athletes. The effect sizes ranged from moderate to large indicating that the differences in performance between stronger versus weaker athletes were very meaningful. The authors conclude that these results illustrate the importance of developing lower body maximal strength in female athletes given its associations with key performance variables.
Thomas, C., Comfort, P., Jones, P. A., & Dos’ Santos, T. (2016). A Comparison of Isometric Mid-Thigh Pull Strength, Vertical Jump, Sprint Speed, and Change of Direction Speed in Academy Netball Players. International Journal of Sports Physiology and Performance, 1-20.