Physiological determinants of climbing-specific finger endurance and sport rock climbing performance

Abstract

The aim of the study was to examine several physiological responses to a climbing-specific task to identify determinants of endurance in sport rock climbing. Finger strength and endurance of intermediate rock climbers (n = 11) and non-climbers (n = 9) were compared using climbing-specific apparatus. After maximum voluntary contraction (MVC) trials, two isometric endurance tests were performed at 40% (s = 2.5%) MVC until volitional exhaustion (continuous contractions and intermittent contractions of 10 s, with 3 s rest between contractions). Changes in muscle blood oxygenation and muscle blood volume were recorded in the flexor digitorum superficialis using near infra-red spectroscopy. Statistical significance was set at P < 0.05. Climbers had a higher mean MVC (climbers: 485 N, s = 65; non-climbers 375 N, s = 91) (P = 0.009). The group mean endurance test times were similar. The force-time integral, used as a measure of climbing-specific endurance, was greater for climbers in the intermittent test (climbers: 51,769 N x s, s = 12,229; non-climbers: 35,325 N x s, s = 9724) but not in the continuous test (climbers: 21,043 N x s, s = 4474; non-climbers: 15,816 N x s, s = 6263). Recovery of forearm oxygenation during rest phases (intermittent test) explained 41.1% of the variability in the force-time integral. Change in total haemoglobin was significantly greater in non-climbers (continuous test) than climbers (P = 0.023--40% test timepoint, P = 0.014--60% test timepoint). Pressor responses were similar between groups and not related to the force-time integral for either test. We conclude that muscle re-oxygenation during rest phases is a predictor of endurance performance.

Oxygen Recovery Kinetics in the Forearm Flexors of Multiple Ability Groups of Rock Climbers

“…A schematic and picture of the fingerboard and climbing hold is shown in Figure 2. All subjects completed a standardized warm-up and a set of familiarization trials based on the protocol suggested by MacLeod et al, (14), Philippe et al, (17) and Fryer et al, (10,11). All testing was conducted using the subject's dominant arm with the elbow flexed to 90 o and the shoulder externally rotated to 90 o .…”

“…Figure 1 shows a schematic depicting the protocol used during the study. A rock climbing specific fingerboard designed by MacLeod et al, (14) and modified (addition of climbing holds instead of wooden force plate) by Fryer et al, (10,11) was used to conduct all strength and endurance tests (fingerboard the between-day coefficient of variation was 0.5 %). A schematic and picture of the fingerboard and climbing hold is shown in Figure 2.…”

“…Previous studies have used near infra-red spectroscopy (NIRS) to assess de-oxygenation (the offloading of oxygen from haemoglobin in the muscle tissue) during both sustained and intermittent contractions to failure, but have not been used to assess oxidative capacity per se (10,11,14,17). Tissue oxygen (O2) recovery assessed using NIRS has been shown to have a similar time constant to phosphocreatine (PCr) re-synthesis assessed using magnetic resonance spectroscopy (15), and so the application of NIRS may provide useful information on muscle tissue oxidative capacity in climbers.…”

“…Rock climbing has been shown to involve large periods of time spent cycling between sustained and intermittent isometric forearm contractions (9), and so oxidative capacity in the highly stressed local muscle groups is important, and has become a prominent area of interest (10,11,14,17). Previous studies have used near infra-red spectroscopy (NIRS) to assess de-oxygenation (the offloading of oxygen from haemoglobin in the muscle tissue) during both sustained and intermittent contractions to failure, but have not been used to assess oxidative capacity per se (10,11,14,17).…”

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

“…It involves repeated isometric forearm muscle contractions (Macleod, Sutherland, Buntin, Whitaker, Aitchison, Watt, Bradley and Grant, 2007) and whilst the precise level of forces produced during ascents are unknown the percentage of forearm maximal voluntary contraction at which climbers must work vary considerably, especially given the occasional dependence on lower limbs for upward propulsion (Sheel, Seddon, Knight, McKenzie and Warburton, 2003), where approximately 57% of vertical forces are applied to the feet in the standard vertical position (Noẻ, Quaine and Martin, 2001). Although intramuscular pressure may vary between muscle groups and individuals, blood flow is insufficient to maintain homeostasis at intensities 3 greater than 10% MVC (Sjøgaard, Savard and Juel, 1988).…”