INTRODUCTION: This study aimed to assess the efficacy of a six-week cycling-specific, isometric resistance training programme on peak power output (PPO) in elite cyclists. METHODS: Twenty-four elite track sprint cyclists were allocated to EXP (n=13, PPO, 1537 ± 307 W) and CON (n=11, PPO, 1541 ± 389 W) groups. All participants completed a six-week training programme; training content was identical except participants in the EXP group replaced their usual compound lower body resistance training exercise with a cycling-specific, isometric resistance training stimulus. Cycling PPO, knee extensor and cycling-specific isometric strength, and measures of muscle architecture were assessed pre- and post-training. RESULTS: In EXP, absolute and relative PPO increased (46 ± 62 W and 0.8 ± 0.7 W⋅kg-1 , p < 0.05), and the change in relative PPO was different to CON (-0.1 ± 1.0 W⋅kg-1 , group × time interaction p = 0.02). The increase in PPO was concurrent with an increase in extrapolated maximal torque in EXP (7.1 ± 6.5 N⋅m, p = 0.007), but the effect was not different from the change in CON (2.4 ± 9.7 N⋅m, group × time p = 0.14). Cycling-specific isometric strength also increased more in EXP (group × time p = 0.002). There were no other between-group differences in response to training. CONCLUSION: A six-week novel, cycling-specific isometric resistance training period improved PPO in a group of elite sprint cyclists by 3-4%. These data support the use of a cycling-specific isometric resistance training stimulus in the preparation programmes of world-class cyclists.