Purpose: Although ischaemic preconditioning (IPC), induced by cycles of transient limb ischaemia and reperfusion, seems to improve exercise performance, the optimal duration of ischaemia–reperfusion cycles is not established. The present study investigated the effect of ischaemia–reperfusion duration within each IPC cycle on performance in a 2000-m rowing ergometer test. Methods: After incremental and familiarization tests, 16 trained rowers (mean ± SD: age, 24 ± 11 years; weight, 74.1 ± 5.9 kg; V˙ O 2 peak, 67.2 ± 7.4 mL˙kg−1˙min−1) were randomly submitted to a 2000-m rowing test preceded by intermittent bilateral cuff inflation of the lower limbs with three cycles of ischaemia–reperfusion, lasting 5 min (IPC-5) or 10 min (IPC-10) at 220 or 20 mmHg (control). Power output, V˙ O 2, heart rate, blood lactate concentration, pH, ratings of perceived exertion (RPE), and near-infrared spectroscopy-derived measurements of the vastus lateralis muscle were continuously recorded. Results: No differences among treatments were found in the 2000-m test (control: 424 ± 17; IPC-5: 425 ± 16; IPC-10: 424 ± 17 s; P = 0.772). IPC-10 reduced the tissue saturation index and oxy-haemoglobin concentration during exercise compared with control. The power output during the last 100-m segment was significantly lower with IPC-10. The IPC treatments increased the heart rate over the first 500 m and decreased the pH after exercise. No alterations were observed in V˙ O 2, blood lactate, or RPE among the trials. Conclusion: In conclusion, IPC does not improve the 2000-m rowing ergometer performance of trained athletes regardless of the length of ischaemia–reperfusion cycles.