Ischemic preconditioning does not improve maximal power output or maximal oxygen consumption but attenuates rating of perceived exertion - a crossover study
Translated title
Iskæmisk prækonditionering forbedrer ikke maksimal ydeevne eller maksimalt iltoptag men dæmper opfattelse af anstrengelsesgrad
Authors
Jokumsen, Peter Sørensen ; ter Beek, Frank
Term
4. semester
Education
Publication year
2019
Pages
23
Abstract
Nogle studier har foreslået, at kortvarigt at klemme blodtilførslen af og på til en arm eller et ben med en blodtryksmanchet før træning—iskæmisk præconditioning (IPC)—kan forbedre cykelpræstation. Vi undersøgte, om IPC ændrer maksimal effekt (MPO), maksimal iltoptagelse (VO2max), hvor hård indsatsen føles (RPE, Borg 6–20), og flere fysiologiske reaktioner. I et dobbeltblindet, randomiseret crossover-studie gennemførte 14 unge, raske mænd et introduktionsbesøg og derefter to testbesøg. Før cykling modtog de enten IPC (fire 5‑minutters perioder med 250 mmHg afklemning adskilt af 5 minutter med gennemblødning) eller en skinnetilstand (20 mmHg). De gennemførte herefter en step‑transition test og en maksimal trinvist cykelergometertest; ved andet besøg fik de den modsatte tilstand. Testpersonalet kendte ikke til behandlingen. Vi målte effekt, VO2 og VO2max, hjertefrekvens, blodlaktat og muskeloksygenering (ved nær‑infrarød spektroskopi) samt RPE. Sammenlignet med skinnetilstanden ændrede IPC ikke MPO, VO2max, maksimal puls eller mål for muskeldeoksygenering. Der var heller ingen ændringer i VO2, puls eller muskeloksygenering ved submaksimale belastninger. Deltagerne rapporterede dog lavere RPE ved 245 W og 280 W, men ikke ved lavere intensiteter, når der blev korrigeret for flere sammenligninger. IPC påvirkede heller ikke VO2, puls, blodlaktat eller RPE i step‑transition testen. Konklusion: Hos unge, raske mænd forbedrede IPC ikke cykelpræstation eller de målte fysiologiske responser, men de højeste belastninger føltes en smule lettere.
Some studies suggest that briefly restricting and restoring blood flow to a limb with a blood pressure cuff before exercise—called ischemic preconditioning (IPC)—might boost cycling performance. We examined whether IPC changes maximal power output (MPO), maximum oxygen uptake (VO2max), how hard the effort feels (rating of perceived exertion, RPE), and several physiological responses. In a double‑blind, randomized crossover study, 14 healthy young men completed a familiarization visit and then two test visits. Before cycling, they received either IPC (four 5‑minute cuff inflations to 250 mmHg separated by 5 minutes of reperfusion) or a low‑pressure sham (20 mmHg). They then performed a step‑transition test and a maximal incremental cycling test; at the second visit they received the other condition. Testers were blinded to treatment. We monitored power, VO2 and VO2max, heart rate, blood lactate, and muscle oxygenation using near‑infrared spectroscopy, and recorded RPE on the Borg 6–20 scale. Compared with sham, IPC did not change MPO, VO2max, peak heart rate, or indices of muscle deoxygenation. It also did not alter VO2, heart rate, or muscle oxygenation at submaximal workloads. However, participants reported lower RPE at 245 W and 280 W, but not at lower intensities after adjusting for multiple comparisons. IPC also had no effect on VO2, heart rate, blood lactate, or RPE in the step‑transition test. Conclusion: In healthy young men, IPC did not improve cycling performance or measured physiological responses, but the highest workloads felt slightly easier.
[This abstract was generated with the help of AI]
Keywords
Documents
Other projects by the authors
Jokumsen, Peter Sørensen:
- Ischemic preconditioning attenuates pain perception following eccentric exercise - a crossover-study (2018)
ter Beek, Frank: