Ischemic preconditioning delays the time of exhaustion in cycling performance during the early but not in the late phase

A Practical Approach for Ischemic Preconditioning Intervention in Sports: A Pilot Study for Cuff Thigh Occlusion Pressure Estimation Based on Systolic Blood Pressure

For the ischemic preconditioning (IPC) intervention, the accuracy of the protocol is paramount for mediating its possible ergogenic effects. However, the lack of standardization and widespread use of arbitrary cuff pressures (ranging from 130 to >300 mmHg) have been predominantly observed, potentially affecting the results and compromising the reproducibility of findings. Thus, the purpose of this study was to determine an appropriate cuff pressure during IPC. Seventeen healthy male participants were enrolled in the study. Anthropometric measurements were initially conducted, followed by systolic and diastolic blood pressure measurements. Subsequently, we determined the individual thigh occlusion pressure (TOP) for the right leg using a hand-held Doppler device. Based on these findings, we developed an estimation equation for TOP, considering the current brachial systolic blood pressure (SBP) values. We then conducted a retrospective analysis of its capacity to mediate occlusion. We observed the ability to estimate TOP using the equation (p = 0.01; ES: 0.86), presenting ~6% superiority in absolute values for occlusion compared to direct measurement (TOP equation: 169.9 ± 9.1; TOP direct measured: 161.2 ± 11.1). However, TOP estimation was insufficient to produce complete occlusion in two out of 17 subjects (11.8%). In conclusion, the estimation of TOP incorporating SBP values may offer a valid and practical means for cuff administration during IPC protocols with potential to minimize adverse effects and maximize its positive effects.

Ischemia-Reperfusion Intervention: From Enhancements in Exercise Performance to Accelerated Performance Recovery-A Systematic Review and Meta-Analysis

It has been demonstrated that brief cycles of ischemia followed by reperfusion (IR) applied before exercise can improve performance and, IR intervention, applied immediately after exercise (post-exercise ischemic conditioning—PEIC) exerts a potential ergogenic effect to accelerate recovery. Thus, the purpose of this systematic review with meta-analysis was to identify the effects of PEIC on exercise performance, recovery and the responses of associated physiological parameters, such as creatine kinase, perceived recovery and muscle soreness, over 24 h after its application. From 3281 studies, six involving 106 subjects fulfilled the inclusion criteria. Compared to sham (cuff administration with low pressure) and control interventions (no cuff administration), PEIC led to faster performance recovery (p = 0.004; ES = −0.49) and lower increase in creatine kinase (p < 0.001; effect size (ES) = −0.74) and muscle soreness (p < 0.001; ES = −0.88) over 24 h. The effectiveness of this intervention is more pronounced in subjects with low/moderate fitness level and at least a total time of 10 min of ischemia (e.g., two cycles of 5 min) is necessary to promote positive effects.

Ischemic preconditioning improves performance and accelerates the heart rate recovery

BACKGROUND

Previous studies have assessed the effects of ischemic preconditioning (IPC) on exercise performance and physiological variables, such as lactate and muscle deoxygenation. In this study, we verified the IPC effects on performance and heart rate during and immediately after a maximal incremental cycling test (ICT).

METHODS

Eighteen recreationally trained cyclists (28±4 years) were allocated to one of three groups: IPC, SHAM and Control. After the first visit to familiarization, cyclists attended the laboratory on two separate occasions to perform an ICT: in the 1^st visit they performed the reference test (baseline), and in 2^nd the test ischemic preconditioning (2 cycles of 5-min occlusion [at 50 mm Hg above systolic arterial pressure]/ 5-min reperfusion), SHAM (identical to ischemic preconditioning, but at 20 mm Hg) or control (no occlusion) interventions (post intervention). During the ICT, heart rate, power output and perceived exertion were measured and the heart rate was monitored throughout the recovery.

RESULTS

Only ischemic preconditioning group improved performance time by 4.9±4.0% and decreased heart rate at submaximal point during ICT, of 170±8 to 166±8 bpm (P<0.05). Also, IPC promoted faster heart rate recovery, mainly on first minute (from 151±9 to 145±8 bpm; P<0.05), compared to baseline. No differences for other parameters were found.

CONCLUSIONS

Two cycles of five minutes of ischemia were relevant to produce positive effects on performance and alter the heart rate during and soon after ICT.