Our purpose was to examine the effects of altering cadence on 5- mile (8.045 km) time-trial (TT) performance in well-trained amateur male cyclists. Twelve cyclists (mean (SD) age: 24 (4) y; body mass: 70.9 (5.9) kg; and VO2max: 4.56 (0.52) L · min -1 ) rode three 5-mile TT. The first was at their freely chosen or preferred cadence (PC); the other two, high cadence (HC; PC + 10.8 %) and low cadence (LC; PC - 9.2%), were randomly assigned and com- pleted in a counterbalanced crossover design. Subjects rode their own bicycles, fitted with a power meter, and attached to a wind- load simulator. Practice sessions were completed 2d prior to each TT. Cadences for PC, LC, and HC were 92(2 ), 83 (6), 101 (6) rpm, respectively; they were also significantly different from each other (p < 0.05). LC was 2.5 % faster than HC and more eco- nomical than HC and PC (66 (3), 69 (2), 71 (4 W · L -1 O2 ·m in -1 , re- spectively) (p ≤ 0.05). LC heart rate and ventilatory efficiency (VE/ VO2-ratio) were lower than PC counterparts, while LC and HC mi- nute ventilation (VE) were less than PC VE (p < 0.05). LC may be the optimal cadence for 5 mile TT in well-trained amateur male cyclists because LC was the most economical, was faster than HC, resulted in the greatest proportion of fastest times (58 % vs. 25 % and 17 % for PC and HC, respectively), and elicited less cardiore- spiratory strain than PC.