Brachial artery characteristics and micro‐vascular filtration capacity in rock climbers

Abstract

Rock climbers perform repeated isometric forearm muscle contractions subjecting the vasculature to repeated ischaemia and distorted haemodynamic signals. This study investigated forearm vascular characteristics in rock climbers compared to healthy untrained controls. Eight climbers (CLIMB) (BMI; 22.3, s = 2.0 kg/m 2 , isometric handgrip strength; 46, s = 8 kg) were compared against eight untrained controls (CON) (BMI; 23.8, s = 2.6 kg/m 2 , isometric handgrip strength; 37, s = 9 kg). Brachial artery diameter and blood flow were measured, using Doppler ultrasound, at rest and following 5-mins ischaemia (peak diameter) and ischaemic exercise (maximal dilation) to calculate flow mediated dilation (FMD) and dilatory capacity (DC). Capillary filtration capacity was assessed using venous occlusion plethysmography. Resting (4.30, s = 0.26 vs. 3.79, s = 0.39 mm), peak (4.67, s = 0.31 vs. 4.12, s = 0.45 mm) and maximal (5.14, s = 0.42 vs. 4.35, s = 0.47 mm) diameters were greater (P < 0.05) in CLIMB than CON, respectively, despite no difference in FMD (9.2, s = 2.6 vs. 8.7, s = 2.9%). Peak reactive hyperaemic blood flow (1136, s = 504 vs. 651, s = 221 ml/min) and capillary filtration capacity (3.8, s = 0.9 vs. 5.2, s = 0.7 ml.min −1 .mmHg −1 .100 ml tissue −1 × 10 −3 ) were greater (P < 0.05) in CLIMB compared to CON, respectively. Rock climbers exhibit structural vascular adaptation compared to untrained control participants but have similar vascular function. This may contribute to the enhanced ability of climbers to perform repeated isometric contractions.

Handgrip Fatigue and Forearm Girth in Intermediate Sport Rock Climbers

“…These results demonstrate that rock climbers have increased vasculature which provides information that repeated isometric ischemic conditions enhance vascular adaptations 19 . The results of our study show a 4.5% increase in forearm girth in the dominant hand and a 4.4% increase in forearm girth in the non-dominant hand.…”

“…Cold water immersion is a technique that is believed to induce localized vasoconstriction which reduces acute inflammation in the forearms 18 . Previously, vascular characteristics of rock climbers have been compared to untrained individuals, where brachial artery diameter and blood flow were measured 19 . It was hypothesized that rock climbers would show enlarged artery diameter and enhanced capillary filtration and capillary density 20 .…”

Active recovery of the finger flexors enhances intermittent handgrip performance in rock climbers

“…As such climbing ability on short bouldering routes may not be associated with the amount of re-oxygenation, but rather the type of climbing that the climbers predominantly took part in. It has been previously shown that in sport climbers, local vascular adaptations represent a higher reactive hyperaemic blood flow and capillary filtration capacity of forearm muscles (Thompson, Farrow, Hunt, Lewis, & Ferguson, 2014). These adaptations are due to the oxygen demands of the activity (sport climbing) generally lasting between two to seven minutes (Watts, 2004).…”

Forearm muscle oxygenation during sustained isometric contractions in rock climbers

“…According to these results, it is suggested that these differences are due to climbing discpline-specific finger flexor adaptations. Previous research (Fryer, Stoner, Scarrott et al, 2015) has suggested that there are no differences in the macrovascular structure of the finger flexors between ability groups, although microvascular adaptions have been reported (Thompson, Farrow, Hunt, Lewis & Ferguson, 2014). Moreover, experienced climbers have been shown to be able to deoxygenate the FDP to a greater extent than their lower grade counterparts (Fryer et al, 2014;Fryer, Stoner, Scarrott et al, 2015;.…”