To investigate the effects of custom-made foot orthoses on the torque- and power-cadence relationships and perceived comfort during maximal cycling exercises in a population of competitive road cyclists.Randomised, repeated measures, participant-blinded controlled study.Twenty-four competitive road cyclists (22 males, 2 females; aged 18-53 years) with mobile feet performed the torque-velocity test with custom-made and sham foot orthoses. For both conditions, the maximal power, optimal cadence, optimal torque, maximal torque, and maximal cadence were extracted from the individual torque- and power-cadence relationships. Comfort was assessed on a 150mm visual analogue scale. Paired-samples t-tests were used for comparison of means between conditions.No differences were observed between the custom-made and sham foot orthoses for any of the key variables extracted: maximal power (1022±180 vs. 1020±172W; p=0.794), optimal cadence (118±10 vs. 119±9rpm; p=0.682), optimal torque (82±10 vs. 82±11Nm; p=0.559), maximal torque (157±23 vs. 159±20 Nm; p=0.665) and maximal cadence (220±22 vs. 221±20rpm; p=0.935). There was no difference in comfort between custom-made and sham foot orthoses (106±30.5 vs. 116±25.0mm; p=0.995).Compared to the sham foot orthoses, the custom-made foot orthoses did not significantly affect the torque and power generating capacities or comfort during a maximal exercise performed on a stationary cycle ergometer.