Vascular and oxygenation responses of local ischemia and systemic hypoxia during arm cycling repeated sprints

Abstract

Objectives: The purpose of this study was to investigate the acute vascular and oxygenation responses to repeated sprint exercise during arm cycling with either blood flow restriction (BFR) or systemic hypoxia alone or in combination. Design: The study design was a single-blinded repeated-measures assessment of four conditions with two levels of normobaric hypoxia (400 m and 3800 m) and two levels of BFR (0% and 45% of total occlusion). Methods: Sixteen active participants (eleven men and five women; mean ± SD; 26.4 ± 4.0 years old; 73.8 ± 9.8 kg; 1.79 ± 0.07 m) completed 5 sessions (1 familiarization, 4 conditions). During each test visit, participants performed a repeated sprint arm cycling test to exhaustion (10 s maximal sprints with 20 s recovery until exhaustion) to measure power output, metabolic equivalents, blood flow, as well as oxygenation (near-infrared spectroscopy) of the biceps brachii muscle tissue. Results: Repeated sprint performance was decreased with both BFR and systemic hypoxia conditions. Greater changes between minimum-maximum of sprints in total hemoglobin concentration ([tHb]) were demonstrated with BFR (400 m, 45% and 3800 m, 45%) than without (400 m, 0% and 3800 m, 0%) (p < 0.001 for both). Additionally, delta tissue saturation index (TSI) decreased more with both BFR conditions than without (p < 0.001 for both). The absolute maximum TSI was progressively reduced with both BFR and systemic hypoxia (p < 0.001). Conclusions: By combining high-intensity, repeated sprint exercise with BFR and/or systemic hypoxia, there is a robust stimulus detected by increased changes in blood perfusion placed on specific vascular mechanisms, which were more prominent in BFR conditions.

High-Intensity Exercise With Blood Flow Restriction or in Hypoxia as Valuable Spaceflight Countermeasures?

“…Additionally, the magnitude and location (conduit, resistance, capillary vessel) of the vascular adaptations depend on the intensity, volume of exposure, and mode of training (Green et al, 2011). Indeed, when combining BFR and/or systemic hypoxia with high-intensity exercise, a robust stimulus is placed on the vascular mechanisms (Willis et al, 2018, 2019a,b). These different methods of systemic and local hypoxia along with the differing underlying mechanisms (metabolic vasodilation and vascular resistance, respectively) can provide a great stimulus alone or in combination to alter vascular conductance and blood flow regulation.…”

“…When high-intensity exercise is performed with BFR, in addition to a strong deoxygenation due to the localized hypoxia, there is a larger increase in the changes in blood perfusion in both legs and arms (vastus lateralis and biceps brachii, respectively) (Willis et al, 2018, 2019b). High-intensity exercise with BFR is able to create a potent stimulus via vascular resistance and altered vasodilatory responses, and was shown to be more robust than with systemic hypoxia in both legs and arms (Peyrard et al, 2019; Willis et al, 2019a,b). In fact, during high-intensity exercise with a certain level of BFR, an additional stimulus of systemic hypoxia is likely blunted (Willis et al, 2019a).…”

“…Incorporating high-intensity exercise training in hypoxia with legs or arms is beneficial for improving performance and delaying fatigue by way of adaptations to improve muscle oxygenation, specifically of the vastus lateralis and triceps brachii (Faiss et al, 2013, 2014). Furthermore, acutely performing high-intensity exercise with BFR elicits greater reactivity regarding changes in blood volume and oxygenation than with systemic hypoxia alone in both the legs and arms (vastus lateralis and biceps brachii, respectively) (Willis et al, 2018, 2019b), with a greater effect in the arms (Willis et al, 2019a). Altogether, utilizing these training methods is beneficial for increasing the efficiency of blood and oxygen transport allowing increased vascular proficiency.…”

Active Preconditioning With Blood Flow Restriction or/and Systemic Hypoxic Exposure Does Not Improve Repeated Sprint Cycling Performance

“…The present RSE (10 s:20 s) likely induces a high anaerobic contribution as shown by previous research (Girard et al, 2011; Bishop, 2012). It was reported that RSE induces different acute hemodynamic responses when performed to exhaustion either in systemic hypoxia or with BFR (Willis et al, 2017, 2018) with greater changes in total hemoglobin present during BFR conditions (Willis et al, 2019). Both from a mechanistic and a practical point of view, it is of interest to investigate if IPC and HPC would also induce greater changes in the hemodynamic response of deoxygenation and total hemoglobin during RSE.…”

Acute physiological responses to arm-cranking with blood flow restriction

“…Considering these differences, it is uncertain if aerobic exercise with BFR will elicit similar physiological responses in the upper-body as those observed in the lower-body. Two groups [70,71] have reported acute physiological responses to supramaximal arm cranking with BFR.…”