Ischemic preconditioning accelerates muscle deoxygenation dynamics and enhances exercise endurance during the work-to-work test
| Autor: | Kido, Kohei, Suga, Tadashi, Tanaka, Daichi, Honjo, Toyoyuki, Homma, Toshiyuki, Fujita, Satoshi, Hamaoka, Takafumi, Isaka, Tadao |
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| Rok vydání: | 2015 |
| Předmět: |
medicine.medical_specialty
near-infrared spectroscopy Physiology Nitric oxide chemistry.chemical_compound nitric oxide Physiology (medical) Internal medicine Occlusion medicine skeletal muscle Exercise Deoxygenation Original Research business.industry Skeletal muscle Intensity (physics) mitochondria medicine.anatomical_structure chemistry Physical therapy Exercise intensity Cardiology Ischemic preconditioning business Anaerobic exercise |
| Zdroj: | Physiological Reports |
| DOI: | 10.14814/phy2.12395 |
| Popis: | Ischemic preconditioning (IPC) improves maximal exercise performance. However, the potential mechanism(s) underlying the beneficial effects of IPC remain unknown. The dynamics of pulmonary oxygen uptake (VO2) and muscle deoxygenation during exercise is frequently used for assessing O2 supply and extraction. Thus, this study examined the effects of IPC on systemic and local O2 dynamics during the incremental step transitions from low- to moderate- and from moderate- to severe-intensity exercise. Fifteen healthy, male subjects were instructed to perform the work-to-work cycling exercise test, which was preceded by the control (no occlusion) or IPC (3 × 5 min, bilateral leg occlusion at >300 mmHg) treatments. The work-to-work test was performed by gradually increasing the exercise intensity as follows: low intensity at 30 W for 3 min, moderate intensity at 90% of the gas exchange threshold (GET) for 4 min, and severe intensity at 70% of the difference between the GET and VO2 peak until exhaustion. During the exercise test, the breath-by-breath pulmonary VO2 and near-infrared spectroscopy-derived muscle deoxygenation were continuously recorded. Exercise endurance during severe-intensity exercise was significantly enhanced by IPC. There were no significant differences in pulmonary VO2 dynamics between treatments. In contrast, muscle deoxygenation dynamics in the step transition from low- to moderate-intensity was significantly faster in IPC than in CON (27.2 ± 2.9 vs. 19.8 ± 0.9 sec, P |
| Databáze: | OpenAIRE |
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