Ischemic Preconditioning Maintains Performance on Two 5-km Time Trials in Hypoxia.

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Serval ID
serval:BIB_0D14F32F6842
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Ischemic Preconditioning Maintains Performance on Two 5-km Time Trials in Hypoxia.
Journal
Medicine and science in sports and exercise
Author(s)
da Mota G.R., Willis S.J., Sobral NDS, Borrani F., Billaut F., Millet G.P.
ISSN
1530-0315 (Electronic)
ISSN-L
0195-9131
Publication state
Published
Issued date
11/2019
Peer-reviewed
Oui
Volume
51
Number
11
Pages
2309-2317
Language
english
Notes
Publication types: Journal Article ; Randomized Controlled Trial ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
The ergogenic effect of ischemic preconditioning (IPC) on endurance exercise performed in hypoxia remains debated and has never been investigated with successive exercise bouts. Therefore, we evaluated if IPC would provide immediate or delayed effects during two 5-km cycling time trials (TT) separated by ~1 h in hypoxia.
In a counterbalanced randomized crossover design, 13 healthy males (27.5 ± 3.6 yr) performed two maximal cycling 5-km TT separated by ~1 h of recovery (TT1 25 min and TT2 2 h post-IPC/SHAM), preceded by IPC (3 × 5 min occlusion 220 mm Hg/reperfusion 0 mm Hg, bilaterally on thighs) or SHAM (20 mm Hg) at normobaric hypoxia (fraction of inspired oxygen [FiO2] of 16%). Performance and physiological (i.e., oxyhemoglobin saturation, heart rate, blood lactate, and vastus lateralis oxygenation) parameters were recorded.
Time to complete (P = 0.011) 5-km TT and mean power output (P = 0.005) from TT1 to TT2 were worse in SHAM, but not in IPC (P = 0.381/P = 0.360, respectively). There were no differences in time, power output, or physiological variables during the two TT between IPC and SHAM. All muscle oxygenation indices differed (P < 0.001) during the IPC/SHAM with a greater deoxygenation in IPC. During the TT, there was a greater concentration of total hemoglobin in IPC than SHAM (P = 0.047) and greater total hemoglobin in TT1 than TT2. Further, the concentration of oxyhemoglobin was lower during TT2 than TT1 (P = 0.005).
In moderate hypoxia, IPC allowed maintaining a higher blood volume during a subsequent maximal exercise, mitigating the performance decrement between two consecutive cycling TT.
Keywords
Adult, Bicycling/physiology, Cross-Over Studies, Heart Rate, Humans, Hypoxia, Ischemic Preconditioning, Lactic Acid/blood, Male, Muscle, Skeletal/metabolism, Myalgia/etiology, Oxygen Consumption, Oxyhemoglobins/metabolism, Perception/physiology, Physical Endurance/physiology, Single-Blind Method, Time Factors, Young Adult
Pubmed
Web of science
Create date
24/06/2019 9:21
Last modification date
16/02/2021 7:26
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