Shoulder muscle activity in sport climbing in naturally chosen and corrected shoulder positions

Objective: The aim of the study was to determine electromyographic activity of the scapula stabilizing muscles in naturally chosen and corrected shoulder positions in typical static climbing postures. Methods: Six male participants undertook surface electromyography measurement in four climbing postures for two different shoulder positions. The activity of the lower, middle and upper trapezius, serratus anterior, pectoralis major, and sternocleidomastoid was recorded. Electromyographic activity was expressed as the percentage of maximal voluntary contraction (MVC) for each muscle. Results: Climbing postures induced higher activation of middle and lower trapezius in corrected shoulder positions (35.3 ± 11.8 and 61.7 ± 15.4% MVC respectively) than in naturally chosen shoulder positions (18.4 ± 8.9 and 30.1 ± 13.8% MVC respectively). The highest activity of the middle and lower trapezius was found in postures with the arm in external rotation and 90° abduction and in an overhanging posture. Low activation was stated for the other muscles in both shoulder conditions. Conclusion: Results showed that climbers naturally elevate the shoulder during typical static postures. Corrected shoulder positions induce higher activation of the scapula stabilizing muscles than naturally chosen shoulder positions.N/

New Zealand blackcurrant extract enhances muscle oxygenation during repeated intermittent forearm muscle contractions in advanced and elite rock climbers

Anthocyanin-rich New Zealand blackcurrant (NZBC) may improve forearm muscle oxygenation and enhance performance in high-level rock climbers. As such, using a double-blind, randomized, cross-over design study, twelve participants performed an oxidative capacity assessment, and two successive exhaustive exercise trials (submaximal forearm muscle contractions at 60 % of their maximal volitional contraction). Each visit was conducted following 7-days intake of 600 mg·day-1 NZBC extract or placebo. Oxidative capacity was estimated by calculating the oxygen half time recovery using near infrared spectroscopy. Time to exhaustion (s), impulse (kg·s), and minimum tissue saturation index (min-TSI %) were assessed during both the exercise trials. Muscle oxidative capacity was greater with NZBC (mean difference [MD] = 5.3 s, 95% confidence intervals [95% CI] = 0.4 – 10.2 s; p = 0.036; Cohen’s d = 0.94). During the exercise trials, there was an interaction for min-TSI % (time x condition, p = 0.046; ηp2 = 0.372), which indicated a greater level of oxygen extraction during trial two with NZBC extract (MD = 9 %, 95% CI = 2-15 %) compared to the placebo (MD = 2 %, 95% CI = 1 - 7 %). There was a decrease in time to exhaustion (p <0.001, ηp2 =0.693) and impulse (p = 0.001, ηp2 =0.672) in exercise trial two, with no effect of NZBC extract. In high level rock climbers 7-days NZBC extract improves forearm muscle oxygenation with no effect on isolated forearm muscle performance

Forearm muscle oxidative capacity index predicts sport rock-climbing performance

Abstract: Rock-climbing performance is largely dependent on the endurance of the forearm flexors. Recently, it was reported that forearm flexor endurance in elite climbers is independent of the ability to regulate conduit artery (brachial) blood flow, suggesting that endurance is not primarily dependent on the ability of the brachial artery to deliver oxygen, but rather the ability of the muscle to perfuse and use oxygen, i.e., skeletal muscle oxidative capacity. Purpose: The aim of the study was to determine whether an index of oxidative capacity in the flexor digitorum profundus (FDP) predicts the best sport climbing red-point grade within the last 6 months. Participants consisted of 46 sport climbers with a range of abilities. Methods: Using near-infrared spectroscopy, the oxidative capacity index of the FDP was assessed by calculating the half-time for tissue oxygen resaturation (O2HTR) following 3–5 min of ischemia. Results: Linear regression, adjusted for age, sex, BMI, and training experience, revealed a 1-s decrease in O2HTR was associated with an increase in red-point grade by 0.65 (95 % CI 0.35–0.94, Adj R2 = 0.53). Conclusions: Considering a grade of 0.4 separated the top four competitors in the 2015 International Federation Sport Climbing World Cup, this finding suggests that forearm flexor oxidative capacity index is an important determinant of rock-climbing performance

A comparison of body composition assessment methods in climbers: Which is better?

Objective To compare body composition estimations of field estimation methods: Durnin & Womersley anthropometry (DW-ANT), bioelectrical impedance analysis (BIA) and Deborah-Kerr anthropometry (DK-ANT) against dual-energy X-ray absorptiometry (DXA) in a male Chilean sport climbing sample. Methods 30 adult male climbers of different performance levels participated in the study. A DXA scan (Lunar Prodigy (R)) was used to determine fat mass, lean mass and total bone mineral content (BMC). Total muscle mass (MM, kg) was estimated through a validated prediction model. DW-ANT and BIA ("non-athletes" and "athletes" equations) were used to determinate fat mass percentage (FM %), while DK-ANT was utilized to estimate MM and BMC. Results A significant (p<0.01) inter-method difference was observed for all methods analyzed. When compared to DXA, DW-ANT and BIA underestimated FM% and DK-ANT overestimated MM and BMC (All p< 0.01). The inter-method differences was lower for DW-ANT. Discussion We found that body composition estimation in climbers is highly method dependent. If DXA is not available, DW-ANT for FM% has a lower bias of estimation than BIA in young male Chilean climbers. For MM and BMC, further studies are needed to compare and estimate the DK-ANT bias level. For both methods, correction equations for specific climbing population should be considered

Comparative grading scales, statistical analyses, climber descriptors and ability grouping: International Rock Climbing Research Association position statement

The research base for rock climbing has expanded substantially in the past 3 decades as worldwide interest in the sport has grown. An important trigger for the increasing research attention has been the transition of the sport to a competitive as well as recreational activity and the potential inclusion of sport climbing in the Olympic schedule. The International Rock Climbing Research Association (IRCRA) was formed in 2011 to bring together climbers, coaches and researchers to share knowledge and promote collaboration. This position statement was developed during and after the 2nd IRCRA Congress which was held in Pontresina, in September 2014. The aim of the position statement is to bring greater uniformity to the descriptive and statistical methods used in reporting rock climbing research findings. To date there is a wide variation in the information provided by researchers regarding the climbers’ characteristics and also in the approaches employed to convert from climbing grading scales to a numeric scale suitable for statistical analysis. Our paper presents details of recommended standards of reporting that should be used for reporting climber characteristics and provides a universal scale for the conversion of climbing grades to a number system for statistical analysis

Differences in forearm strength, endurance, and hemodynamic kinetics between male boulderers and lead rock climbers

This study examined differences in the oxygenation kinetics and strength and endurance characteristics of boulderers and lead sport climbers. Using near infrared spectroscopy, 13-boulderers, 10-lead climbers, and 10-controls completed assessments of oxidative capacity index and muscle oxygen consumption (mV̇O2) in the flexor digitorum profundus (FDP), and extensor digitorum communis (EDC). Additionally, forearm strength (maximal volitional contraction MVC), endurance (force–time integral FTI at 40% MVC), and forearm volume (FAV and ΔFAV) was assessed. MVC was significantly greater in boulderers compared to lead climbers (mean difference = 9.6, 95% CI 5.2–14 kg). FDP and EDC oxidative capacity indexes were significantly greater (p = .041 and .013, respectively) in lead climbers and boulderers compared to controls (mean difference = −1.166, 95% CI (−3.264 to 0.931 s) and mean difference = −1.120, 95% CI (−3.316 to 1.075 s), respectively) with no differences between climbing disciplines. Climbers had a significantly greater FTI compared to controls (mean difference = 2205, 95% CI= 1114–3296 and mean difference = 1716, 95% CI = 553–2880, respectively) but not between disciplines. There were no significant group differences in ΔFAV or mV̇O2. The greater MVC in boulderers may be due to neural adaptation and not hypertrophy. A greater oxidative capacity index in both climbing groups suggests that irrespective of climbing discipline, trainers, coaches, and practitioners should consider forearm specific aerobic training to aid performance.N/

The estimation of critical angle in climbing as a measure of maximal metabolic steady state

Purpose. Sport climbing is a technical, self-paced sport and the workload is highly variable and mainly localized to the forearm flexors. It has not proved effective to control intensity using measures typical of other sports, such as gas exchange thresholds, heart rate or blood lactate. Therefore, the purposes of the study were to 1) determine the possibility of applying the mathematical model of critical power to the estimation of a critical angle (CA) as a measure of maximal metabolic steady state in climbing, and 2) to compare this intensity with the muscle oxygenation breakpoint (MOB) determined during an exhaustive climbing task. Materials and Methods. Twenty-seven sport climbers undertook three to five exhaustive ascents on a motorized treadwall at differing angles to estimate CA, and one exhaustive climbing test with a progressive increase in angle to determine MOB, assessed using near infrared spectroscopy. Results. Model fit for estimated CA was very high (R2=0.99; SEE=1.1°). The mean peak-angle during incremental test was -17±5° and CA from exhaustive trials was found at -2.5±3.8°. Nine climbers performing the ascent 2° under CA were able to sustain the task for 20 min with perceived exertion at 12.1±1.9 (RPE). However, climbing 2° above CA led to task failure after 15.9±3.0 min with RPE=16.4±1.9. When MOB was plotted against estimated CA, good agreement was stated (ICC=0.80, SEM=1.5°). Conclusion. Climbers, coaches and researchers may use a predefined route with three to five different wall angles to estimate CA as an analogue of critical power to determine a maximal metabolic steady state in climbing. Moreover, a climbing test with progressive increases in wall angle using MOB also appears to provide a valid estimate of CA

Effects of brassinosteroid application on seed germination of Norway spruce, Scots pine, Douglas fir and English oak

We tested the influence of a synthetically-produced brassinosteroid compound (2α,3α,17βtrihydroxy-5α-androstan-6-one) on seed germination in Norway spruce, Scots pine, Douglas fir and English oak. Before germination, 400 seeds of each species were steeped in a brassinosteroid solution and then placed for germination in a growth chamber under (i) optimal humidity and (ii) temporary drought stress (except for oak). Drought stress significantly reduced the germination capacity and germination rate in the control treatments of Norway spruce, Scots pine and Douglas fir. Nonetheless, the application of brassinosteroid significantly reduced the drought-stress effects in seeds of Norway spruce and Scots pine. The drought-stressed Douglas fir did not respond positively to the brassinosteroid application. English oak was germinated only under the optimal humidity regime and no differences in germination were detected between the control and brassinosteroid-treated acorns

Reliability of near-infrared spectroscopy for measuring intermittent handgrip contractions in sport climbers

The use of near infra-red spectroscopy (NIRS) to investigate muscle oxygenation changes during physical tasks such as rock climbing has rapidly increased within recent years; yet there is no known measure of reliability. The current study aimed to determine inter-session reliability and minimal detectable change (MDC) of continuous wave NIRS parameters during intermittent handgrip contractions in rock climbers. Thirty-two sport climbers were tested for exhaustive intermittent handgrip exercise (8s contraction – 2s relief) at 60 % of maximal voluntary contraction on three separate days. During each visit, continuous wave NIRS was used to determine tissue saturation index (TSI) as the measure of tissue oxygenation in the flexor digitorum profundus. To assess the inter-session reliability, the intra-class correlation (ICC), standard error of measurement (SEM), coefficient of variation (CV), and minimal (MDC) were used. Mean de-oxygenation during the contractions provided reliable results (∆ TSI; first trial -8.9 ± 2.9%, second trial -8.8 ± 2.7%, and third trial -8.4 ± 2.6%; ICC = 0.692; SEM = 1.5%; CV=17.2%; MDC = 4.2%). Mean muscle re-oxygenation during the relief periods was similarly reliable (∆ TSI; first trial 9.0 ± 3.1%, second trial 8.8 ± 2.9%, and third trial 8.5 ± 2.7%; ICC = 0.672; SEM = 1.7%; CV=19.0%, MDC = 4.7%). As such, continuous wave NIRS provides a reliable measure of de-oxygenation and re-oxygenation during intermittent contractions to failure in the forearm flexors of rock climbers. Differences exceeding ~4.5% for ∆TSI during contraction and relief periods should be considered meaningful