Effects of remote limb ischemic preconditioning on pulmonary function tests and maximal oxygen uptake

Introduction: Ischemic preconditioning (IPC) protects skeletal muscles from ischemia-reperfusion injury and improves physical exercise performance. The purpose of the present study was to determine whether application of remote ischemic preconditioning (RIPC) of upper limbs would affect the pulmonary function tests and the maximal oxygen consumption (VO2max). Methods: Twenty healthy trained and untrained subjects were examined under 2 experimental conditions of control and RIPC groups. All individuals attended the laboratory twice, once as the control group and the next time as the RIPC group in a counterbalanced order. These visits were at least 1 week apart and were taken place at the same time of the day. RIPC was induced using a protocol of three cycles of 5 min ischemia/5 min reperfusion in both arms. Pulmonary function tests and oxygen saturation (SPO2) were measured before and after the RIPC protocol. VO2max was estimated by the Queen Step Test. Results: Analysis of data revealed that RIPC increased FEV1, FEF25-75 and MVV tests in the untrained group, while it increased FVC, FEV1, FEF25-75 and MVV tests in the trained group. Preconditioning also increased VO2max and the maximal heart rate in trained subjects. Conclusion: These results show that pre-exercise induction of limb ischemic preconditioning improves pulmonary function tests and VO2max especially in trained subjects. Thus, this technique may be appropriate for the enhancement of exercise performance in athletes during competitions and also for improving the respiratory function in different pulmonary diseases in the near future.