Ischemic Preconditioning Does Not Affect Maximal Torque, Perceptions Of Exertion Or Pain When Performed Prior To Fatiguing Exercise

PURPOSE: Ischemic preconditioning (IPC) can reduce the prevalence of reperfusion injury. IPC may also improve exercise tolerance by altering performance and perceptual responses to exercise. The purpose of this investigation was to evaluate the acute effects of IPC on maximal torque, perceptions of exertion, and pain following fatiguing exercise. METHODS: Ten (22.1 ± 2.7 years; 170.9 ± 7.2 cm; 72.6 ± 11.8 kg) recreationally active males (n = 5) and females (n = 5) visited the laboratory on two separate occasions. Participants randomly completed three cycles of IPC at a low (SHAM [20 mmHg]) and high (220 mmHg) pressure. To facilitate IPC, a pneumatic cuff was placed most proximal on the dominant limb and each cycle consisted of pressure applied for five-minutes followed by five-minutes of rest. Immediately after IPC, participants completed one set of unilateral, isotonic leg extension muscle actions to volitional exhaustion at 30% of their one-repetition maximum. Prior to and following one set to volitional exhaustion, participants completed maximal voluntary isometric contractions (MVICs). Ratings of perceived exertion (RPE; 0-10) and pain (0-10) were assessed with a visual analog scale immediately post volitional exhaustion. A two-way, 2 (Condition [low and high]) x 2 (Time [pretest, posttest]) repeated measures ANOVA were performed to assess any mean differences in MVIC torque, while separate paired samples t-tests were used to assess mean differences in RPE and pain between the IPC pressures. RESULTS: There was no significant (p = 0.086) interaction or main effect for Condition (p = 0.636). There was, however, a significant main effect for Time (p = 0.006). Specifically, MVIC torque decreased from pretest (222.5 ± 70.2 Nm) to posttest (200.1 ± 62.4 Nm) (p = 0.006). For RPE, there were no significant (p = 0.591) differences between the low (6.3 ± 2.5 au) and high (6.5 ± 1.9 au) IPC pressures. For pain, there were no significant (p = 0.351) differences between the low (4.7 ± 2.2 au) and high (4.3 ± 1.9 au) IPC pressures. CONCLUSION: One-set to volitional exhaustion induced similar performance, perceptions of exertion, and pain responses that were unaffected by the application of IPC. These findings suggested that acute IPC has no performance-enhancing effect and does not affect perception to an acute bout of fatiguing exercise.