Ischemic preconditioning attenuates rating of perceived exertion but does not improve maximal oxygen consumption or maximal power output

Brief consecutive periods of limb ischemia and reperfusion, known as ischemic preconditioning (IPC), have been reported to increase maximal power output (MPO) during cycling. However, the underlying mechanisms are unclear. Therefore, the purpose of the study was to investigate the effects of IPC on MPO, maximal oxygen consumption (VO2max), muscle oxygenation, and rating of perceived exertion (RPE) during an incremental cycling test. Fourteen healthy young men participated in this double-blinded, randomized crossover study, involving IPC (250 mm Hg; four 5-minute cycles of ischemia) and sham (20 mm Hg) treatment followed by an incremental cycling test to exhaustion. During the cycling test, VO2, RPE, heart rate (HR), blood lactate (BL), and muscle oxygenation and deoxygenation (near-infrared spectroscopy) were measured. MPO, VO2max, HRmax, and muscle deoxygenation did not change with IPC (all p-values > 0.13). Furthermore, IPC had no significant effect on VO2, HR, or muscle oxygenation during the incremental cycling test (all p-values > 0.18). However, IPC attenuated RPE during cycling at 210 W (IPC: median 17.0 [interquartile range 15.3–19.0]; sham: 17.5 [17.0–19.0]; p = 0.007) and 245 W (IPC: 18.0 [17.0–18.8]; sham: 19.0 [18.0–19.8]; p = 0.011). A single session of IPC did not improve MPO, VO2max, or measures of oxygen consumption during the cycling test. However, IPC lowered RPE at 210 and 245 W, suggesting that IPC may attenuate the perception of effort at higher submaximal exercise intensities.