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 1st visit they performed the reference test (baseline), and in 2nd 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.