Impact of ischaemia-reperfusion cycles during ischaemic preconditioning on 2000-m rowing ergometer performance

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. After incremental and familiarization tests, 16 trained rowers (mean +/- SD: age, 24 +/- 11 years; weight, 74.1 +/- 5.9 kg; peak, 67.2 +/- 7.4 mL center dot kg(-1)center dot 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, , 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. 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 , blood lactate, or RPE among the trials. In conclusion, IPC does not improve the 2000-m rowing ergometer performance of trained athletes regardless of the length of ischaemia-reperfusion cycles.