Coach report
How Do CMJ Height and IMTP Peak Vertical Force Change with Age in Youth Female Football Players?
This report examines two complementary measures of lower-body performance in youth female football players.
Counter-movement Jump (CMJ) height was used to assess explosive jump performance
Isometric Mid-Thigh Pull (IMTP) peak vertical force was used to assess maximal lower-body strength.
Although both measures generally improve with age, they represent different physical qualities and therefore provide coaches with different information about athlete development.
CMJ height and IMTP peak vertical force (PVF) are reliable methods for monitoring lower-body power and maximal strength, tracking physical development over time and identifying possible signs of fatigue or inadequate recovery.
Previous research has shown that CMJ height and IMTP peak vertical force generally improve as young athletes mature because strength, coordination and neuromuscular function continue to develop. Therefore, these tests provide coaches with practical methods for monitoring physical development and evaluating the effectiveness of training programmes.
Data summary
IMTP peak vertical force was measured using the Isometric Mid-Thigh Pull (IMTP) test and was used as an indicator of maximal lower-body strength.
How do these develop over time in the talent centre?
There is a moderate to strong positive association between age and countermovement jump (CMJ) height. The analysis shows a clear positive relationship between age and CMJ height. As players get older, their jump height increases, indicating improvements in lower-body power that are expected with normal growth, biological maturation and continued training exposure.
As players get older they jump higher, for every year in the programme they jump 1.4 cm higher
As players get older, their CMJ height improves, reflecting increases in lower-body power and neuromuscular coordination that occur during growth, maturation and continued training.
The coloured points and lines show individual players’ measurements over time, while the black lines represent the overall age-related trends across all players. Both CMJ height and IMTP peak vertical force generally increased with age, although individual rates of development varied.
Although both measures generally improve with age, they represent different physical qualities and therefore provide coaches with different information about athlete development. Consequently, improvements in one measure do not necessarily correspond to improvements in the other.
Coaches should therefore monitor both tests to obtain a more comprehensive understanding of player development and to guide training decisions.
Under 14s Squad Report
Below is a report of how well the u14s squad are performing on the above tests after their latest testing session January 2026.
The U14 CMJ results show clear differences between players, reflecting natural variation in physical development during this important stage of growth. While some athletes already demonstrate strong jump performance, others may benefit from additional strength or power training. Regular monitoring of CMJ performance allows coaches to track individual progress, identify players who require additional support, and adapt training programmes according to each athlete’s development.
The graph shows the IMTP peak vertical force of each U14 athlete tested in January 2026. Differences between players can be seen by comparing the height of the bars, with taller bars representing greater force production. This information helps coaches identify athletes with greater lower-body strength and those who may benefit from additional strength training or monitoring over future testing sessions.
Conclusion
Overall, CMJ height and IMTP peak vertical force both increased with age, indicating improvements in explosive performance and maximal lower-body strength as players matured. However, these measures represent different physical qualities and should therefore be monitored independently. Regular assessment of both CMJ and IMTP enables coaches to identify individual differences in development, evaluate training effectiveness and design programmes that improve both strength and explosive performance.