Isolated finger flexor vs. exhaustive whole-body climbing tests? How to assess endurance in sport climbers?

Abstract

Purpose. Sport climbing requires high intensity finger flexor contractions, along with a substantial whole-body systemic oxygen uptake (V ̇O2) contribution. Although fatigue is often localised to the finger flexors, the role of systemic V ̇O2 and local aerobic mechanisms in climbing performance remains unclear. As such, the primary purpose of this study was to determine systemic and local muscle oxygen responses during both isolated finger flexion and incremental exhaustive whole-body climbing tests. The secondary aim was to determine the relationship of isolated and whole-body climbing endurance tests to climbing ability.Methods. Twenty-two male sport climbers completed a series of isometric sustained and intermittent forearm flexor contractions, and an exhaustive climbing test with progressive steepening of the wall angle on a motorized climbing ergometer. Systemic V ̇O2 and flexor digitorum profundus oxygen saturation (StO2) were recorded using portable metabolic analyser and near-infra red spectroscopy, respectively.Results. Muscle oxygenation breakpoint (MOB) was identifiable during an incremental exhaustive climbing test with progressive increases in angle (82±8% and 88±8% V ̇O2 and heart rate climbing peak). The peak angle from whole-body treadwall test and impulse from isolated hangboard endurance tests were interrelated (R 2 = 0.58-0.64).Peak climbing angle together with mean V ̇O2 and StO2 from submaximal climbing explained 83 % of variance in self-reported climbing ability.Conclusions. Both systemic and muscle oxygen kinetics determine climbing specific endurance. Exhaustive climbing and isolated finger flexion endurance tests are interrelated and suitable to assess climbing specific endurance. An exhaustive climbing test with progressive wall angle allows determination of the MOB.

The Estimation of Critical Angle in Climbing as a Measure of Maximal Metabolic Steady State

“…•kg −1 and lowered muscle oxygen saturation of the FDP by 7% (Baláš et al, 2021). In this study, TTE decreased with steeper wall angle and the association between TTE and wall angle followed a hyperbolic function (Figure 2) same to the power or speed and duration relationship (Jones et al, 2019).…”

“… Noé et al (2001) reported that an increase of 10° (−10° from vertical) induced ∼47% increase in mean vertical force on handholds and, therefore, more intense finger flexor contractions. Furthermore, an increase of wall angle by 15° from vertical elevated heart rate by an average of ∼24 beats per min, oxygen uptake by ∼9 mL⋅min –1 ⋅kg –1 and lowered muscle oxygen saturation of the FDP by 7% ( Baláš et al, 2021 ). In this study, TTE decreased with steeper wall angle and the association between TTE and wall angle followed a hyperbolic function ( Figure 2 ) same to the power or speed and duration relationship ( Jones et al, 2019 ).…”

“…The route was technically simple with positively oriented and slightly crimped holds (2-3 cm size depth which enabled both the open and half-crimp grip positions) and was graded 8 on IRCRA grading scale at vertical angle (0 • ) by a professional routesetter. During all ascents, a speed of 9 m•min −1 was applied to minimize the opportunity for static resting positions during the climbs (Baláš et al, 2021). The incremental test started at +6 • (positive angle), and after each minute, the belt was stopped for 10 s to allow climbers to dry their hands with chalk, following which the angle was decreased by −3 • to become progressively vertical (0 • ) and then negative (overhanging), therefore requiring progressively greater finger flexor and upper-body strength involvement.…”

“…Endurance training in climbing requires systemic and localized adaptations ( Thompson et al, 2014 ; Fryer et al, 2018 ), and ensuring appropriate intensity of exercise, particularly for the finger flexors, is challenging. Indeed, it has been shown that intensity control during climbing using measures typical from other sports, such as gas exchange thresholds, heart rate, and blood lactate, are not effective ( Schöffl et al, 2006 ; Limonta et al, 2018 ; Baláš et al, 2021 ).…”

“…Moreover, with an increased angle, more pronounced finger flexor contractions stimulate mitochondrial respiration and higher intramuscular pressure restricts capillary blood flow and, thus, muscle oxygen delivery ( Fryer et al, 2013 ; Gajdošík et al, 2021 ). Recently, muscle oxygenation breakpoints (MOBs) have been measured locally using near infrared spectroscopy (NIRS) during an incremental climbing task ( Baláš et al, 2021 ). These MOBs were suggested to represent an intensity around localized CP; however, they have not been associated with any systemic metabolic threshold indicators, and as such validation of such a MOB is needed.…”