Influence of passive stretch on muscle blood flow, oxygenation and central cardiovascular responses in healthy young males

Abstract

The aim of this study was to examine the effect of skeletal muscle stretching on peripheral, central, and autonomic cardiovascular responses in humans. Twelve healthy males completed a controlled passive stretch of the plantar flexors for 4 min at three different intensities. Doppler ultrasound velocimetry and imaging techniques assessed mean leg blood flow (MLBF), antegrade blood flow, and retrograde blood flow of the popliteal artery. Near-infrared spectroscopy assessed the concentration of deoxygenated hemoglobin + myoglobin ([HHb]) and the sum of its deoxygenated and oxygenated forms [i.e., blood volume ([Hbtot])]. Heart rate (HR) and mean arterial pressure were measured simultaneously to peripheral hemodynamic responses. During stretch there was an increase (P < 0.05) in antegrade and retrograde blood flow along with [HHb] and [Hbtot] relative to baseline, whereas MLBF was not altered. HR increased (P < 0.01) in a stretch intensity- and time-dependent manner, suggesting a threshold tension must be met that results in a mechanoreflex-mediated increase in HR. After stretch there was an increase (P < 0.05) in [Hbtot] and MLBF in each condition, suggesting that stretch creates a poststretch hyperemic response. Furthermore, retrograde blood flow was decreased (P < 0.05) after stretch in each stretch condition. Mean arterial pressure was decreased (P < 0.05) after moderate-intensity stretching. Collectively, our data provide novel mechanistic evidence on cardiovascular responses to skeletal muscle stretching in humans. Moreover, the reductions in MAP and retrograde blood flow suggest that stretch transiently reduces myogenic vascular tone in a poststretch resting period.

Evidence for improved systemic and local vascular function after long‐term passive static stretching training of the musculoskeletal system

“…Acute passive stretching. The participants rested in a supine position during stretching for the knee extensor (Venturelli et al 2019) and in a prone position for plantar flexor muscles (Kruse et al 2016) for 20 min before starting the data collection and remained in this position throughout the entire duration of the data collection. The two stretching bouts were separate by 60 min rest, during which the participant remained at rest on a medical bed.…”

“…The improvement may stem from repeated changes inẎ during PS and from its effect on NO bioavailability. PS training repeatedly exposed the vessels to increased levels ofẎ (Kruse et al 2016;Venturelli et al 2017aVenturelli et al , 2019, thus stimulating endothelial mechanotransduction signalling in smooth muscle cells that results in vasodilatation ( , Green et al 2017a. Such repeated alterations inẎ over time can be considered as a kind vascular preconditioning that may lead to increase NO bioavailability (Green et al 2017a;Bisconti et al 2019).…”

Effects of static stretching duration on muscle stiffness and blood flow in the rectus femoris in adolescents

“…However, no work evaluating the effect of SS duration in adolescents exists in the literature. Studies related to muscle blood flow used conventional Doppler, micro-CT analysis, gamma scintillation counter or experimental model methods [12,23]. These studies have concluded that there is a reduction in local blood flow during stretching, with an acute post-stretch hyperemic response after stretching and a vascularity increase in the chronic period.…”

Effects of inter-set stretching on acute hormonal and metabolic response: a pilot study

“…Furthermore, Mayhew et al [23] found that a 1-minute rest interval between sets resulted in higher total leukocytes as compared with that of 3 minutes. Kruse et al [24] demonstrated that in humans retrograde muscle blood flow decreased following stretching. Otsuki et al [25] observed a decrease in blood volume accompanied by a general decline in microvascular muscle oxygenation induced by stretching.…”