Purpose: Ischemic preconditioning enhances exercise performance. We tested the hypothesis that ischemic preconditioning would improve intermittent exercise in the form of a repeated sprint test during cycling ergometry. Methods: In a single-blind, crossover study, fourteen recreationally-active males (mean ± SD; age 22.9 ± 3.7 years, height 1.80 ± 0.07 m, mass 77.3 ± 9.2 kg) performed twelve 6 s sprints following four 5 min periods of bilateral limb occlusion at 220 mmHg (ischemic preconditioning) or 20 mmHg (placebo). Results: Ischemic preconditioning resulted in a 2.4 ± 2.2, 2.6 ± 2.7 and 3.7 ± 2.4% substantial increase in peak power for sprints 1, 2 and 3 respectively, relative to placebo, with no further changes between trials observed for any other sprint. Similar findings were observed in the first three sprints for mean power output following ischemic preconditioning (2.8 ± 2.5, 2.6 ± 2.5 and 3.4 ± 2.1%, for sprints 1, 2 and 3 respectively), relative to placebo. Fatigue index was not substantially different between trials. At rest tissue saturation index was not different between trials. During the ischemic preconditioning / placebo stimulus there was a -19.7 ± 3.6% decrease in tissue saturation index in the ischemic preconditioning trial, relative to placebo. During exercise there was a 5.4 ± 4.8% greater maintenance of tissue saturation index in the ischemic preconditioning trial, relative to placebo. There were no substantial differences between trials for blood lactate, electromyography (EMG) median frequency, oxygen uptake or rating of perceived exertion (RPE) at any time points. Conclusion: Ischemic preconditioning improved peak and mean power output during the early stages of repeated sprint cycling and may be beneficial for sprint sports.
Key Words: Ischemia, occlusion, power output, multiple sprint, fatigue
ORCID: https://orcid.org/0000-0003-4667-9939, Bezodis, Neil E.