Exploring the reliability of isometric benchmark tests and their relationship to performance characteristics in elite track sprint cyclists

Benchmark tests in competitive cycling identify talent, individualise training, and monitor performance. However, varying protocols often produce conflicting results, reducing comparability. Isometric tests are prevalent, but reliability and performance correlation are underexplored. Determine the test-retest reliability of benchmark test metrics in elite track sprint cyclists and their relationship to a performance outcome. Nineteen elite track sprint cyclists (12 males, 7 females) completed seven benchmark tests across two days: modified sit-and-reach; on-bike rolling seated maximum 6-s sprints; 3-s bilateral on-bike isometrics at 90° crank angle; 3-s prone bench pull isometrics; 3-s lumbar extension isometrics; 3-s seated off-bike isometrics; and modified plank endurance. For the performance outcome, a third session within 7 days assessed peak power using an inertial load cycle ergometer. All tests showed <i>excellent</i> measurement consistency (ICC_3,1 ≥ 0.92), with low systematic bias (<i>p</i> ≥ 0.063), though confidence interval varied due to modest sample size. High test-retest reliability was supported by low typical errors (CV 2.0-5.5%; 9.6% for endurance). Nine benchmark metrics, including bilateral isometric measures, showed moderate to excellent correlation with peak power output (<i>r</i> = 0.52-0.94, <i>p</i> ≤ 0.023); six remained statistically significant after Bonferroni correction (<i>p</i> ≤ 0.005). All benchmark metrics were reliable, with six strongly and statistically significantly associated with performance.