The Relationship Between Isometric and Dynamic Strength in College Football Players

PURPOSE: To examine the relationships between measures of maximum isometric force (PF), rate of force development (RFD) and one repetition maximum (1RM) in collegiate football athletes. METHODS: The subjects were twenty-two male Division I college football players ((mean ± SD):age 18.4 ± 0.7 years; height 188 ± 7 cm; mass 107.6 ± 22.9 kg). PF and RFD were determined from force-time curves generate from an isometric mid thigh pull exercise. Measures of dynamic strength were represented by the 1RM for squat, bench press and power clean, as well as the 2RM for the split jerk. Vertical jump and standing broad jump were also measured to provide an indication of explosive muscular power. Correlations between the variables were calculated using Pearson product moment correlation coefficients. Strong correlations were defined as any significant (p<.05) correlations where r ≥0.6 or r ≤−0.6. RESULTS: There were strong correlations between measures of PF and the 1RMs (r=0.61 - 0.72). The correlations between the power clean 1RM and squat 1RM were also strong (r = 0.90). There were strong correlations between 2RM split jerk and clean 1RM (r = 0.71), squat 1RM (r = 0.71), bench 1RM (r = 0.70) and PF (r = 0.72). There were no significant correlations with RFD for any variable. CONCLUSIONS: The isometric mid thigh pull test correlates well with 1RM in college football players. RFD does not appear to correlate as well. The isometric mid thigh pull provides an efficient method for assessing isometric strength in athletes. This measure also provides a strong indication of dynamic performance in this population. The lack of strong correlations with other test variables may be a reflection of the unique strength and power qualities.