Ischemic Preconditioning, O 2 Kinetics, and Performance in Normoxia and Hypoxia

Chad C. Wiggins, Keren Constantini, Hunter L. Paris, Timothy D. Mickleborough, Robert F. Chapman*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Introduction: Ischemic preconditioning (IPC) before exercise has been shown to be a novel approach to improve performance in different exercise modes in normoxia (NORM). Few studies have been conducted examining potential mechanisms behind these improvements, and less has been done examining its influence during exercise in hypoxia (HYP). Oxygen uptake and extraction kinetics are factors that have been implicated as possible determinants of cycling performance. We hypothesized that IPC would lead to improvements in oxygen extraction and peripheral blood flow kinetics, and this would translate to improvements in cycling time trial (TT) performance in both NORM and HYP. Methods: Thirteen men (age, 24 ± 7 yr; V-O 2max , 63.1 ± 5.1 mL·kg -1 ·min -1 ) participated in the study. Subjects completed trials of each combination of normobaric HYP (F i O 2 = 0.16, simulating 8000 ft/2500 m) or NORM (F i O 2 = 0.21) with preexercise IPC protocol (4 × 5 min at 220 mm Hg) or SHAM procedure. Trials included submaximal constant load cycle exercise bouts (power outputs of 15% below gas exchange threshold, and 85% of V-O 2max ), and a 5-km cycling performance TT. Results: Ischemic preconditioning significantly improved 5-km TT time in NORM by 0.9% ± 1.8% compared with SHAM (IPC, 491.2 ± 35.2 s vs SHAM, 495.9 ± 36.0 s; P < 0.05). Ischemic preconditioning did not alter 5-km TT performance times in HYP (P = 0.231). Ischemic preconditioning did, however, improve tissue oxygen extraction in HYP (deoxygenated hemoglobin/myoglobin: IPC, 21.23 ± 10.95 μM; SHAM, 19.93 ± 9.91 μM; P < 0.05) during moderate-intensity exercise. Conclusions: Our data confirm that IPC is an effective ergogenic aid for athletes performing 5-km cycling TT bouts in NORM. Ischemic preconditioning did mitigate the declines in tissue oxygen during moderate-intensity exercise in HYP, but this did not translate to a significant effect on mean group performance. These data suggest that IPC may be of benefit for athletes training and competing in NORM.

Original languageEnglish
Pages (from-to)900-911
Number of pages12
JournalMedicine and Science in Sports and Exercise
Issue number5
StatePublished - 1 May 2019
Externally publishedYes




Dive into the research topics of 'Ischemic Preconditioning, O 2 Kinetics, and Performance in Normoxia and Hypoxia'. Together they form a unique fingerprint.

Cite this