Relationship Between Early and Maximal Isometric Upper-Body Push and Pull Force Production Among Elite Female and...

Maximal and explosive strength-defined as the ability to rapidly generate high levels of force-are widely recognized as critical for performance in strength-power sports such as track and field throwing. However, their interrelationship remains insufficiently examined, particularly in the upper body of elite athletes. This study examined the relationship between early force production (≤250 ms, subdivided into early phase: 0-100 ms; late phase: 100-250 ms) and peak isometric upper-body push and pull force in elite Swedish track and field throwers. A total of 30 athletes (17 females, 13 males; aged 18-34 years), all competing nationally or internationally in discus, hammer, shot put, or javelin, participated in a cross-sectional assessment. Isometric force was measured during bench press (push) and supine bench row (pull) using a custom-built device. Force output was recorded at 50, 100, 150, 200, and 250 ms, along with peak force. The results showed a progressive increase in the correlation between force at early time points and peak force. Associations were weak to moderate at 50-100 ms (r = 0.07-0.55) and became strong to very strong at 150-250 ms (r = 0.64-0.92). These patterns were consistent across sexes and test types. The findings suggest that maximal strength becomes increasingly important as force production time extends beyond 100 ms. Coaches may benefit from assessing both early and peak force characteristics to inform strength profiling and guide training focus, though further research is needed to determine their impact on performance.