Secondary Logo

Journal Logo

Institutional members access full text with Ovid®

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

DA MOTA, GUSTAVO R.1,2; WILLIS, SARAH J.2; SOBRAL, NELSON DOS SANTOS2; BORRANI, FABIO2; BILLAUT, FRANÇOIS3; MILLET, GRÉGOIRE P.2

Medicine & Science in Sports & Exercise: November 2019 - Volume 51 - Issue 11 - p 2309–2317
doi: 10.1249/MSS.0000000000002049
APPLIED SCIENCES
Buy

Purpose 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.

Methods 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.

Results 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).

Conclusion In moderate hypoxia, IPC allowed maintaining a higher blood volume during a subsequent maximal exercise, mitigating the performance decrement between two consecutive cycling TT.

1Human Performance and Sport Research Group, Department of Sport Sciences, Institute of Health Sciences, Federal University of Triangulo Mineiro, Uberaba, MG, BRAZIL

2Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND

3Department of Kinesiology, Laval University, Quebec, QC, CANADA

Address for correspondence: Gustavo R. da Mota, Ph.D., Human Performance and Sport Research Group, Department of Sport Sciences, Institute of Health Sciences, Federal University of Triângulo Mineiro, Ave. Tutunas, 490, Uberaba, MG 38061-500, Brazil; E-mail: grmotta@gmail.com.

G. R. d. M. and S. J. W. contributed equally to this study.

Submitted for publication March 2019.

Accepted for publication May 2019.

Online date: July 12, 2019

© 2019 American College of Sports Medicine