Handedness, Bilateral, and Interdigit Strength Asymmetries in Male Climbers.

PURPOSE: To determine whether there are bilateral and interdigit differences in the maximal force production of experienced climbers and whether these differences are mediated by ability level or preferred style of climbing. METHODS: Thirty-six male climbers (age 30 [9.4] y) took part in a single-session trial to test their maximal force production on both hands. The tests included a one-arm maximal isometric finger flexor strength test (MIFS) and a one-arm individual MIFS. Bilateral differences were analyzed by strongest hand (defined as the hand that produced the highest MIFS value) and dominance (defined as the writing hand). RESULTS: A pairwise t test found that MIFS was significantly greater for the strongest hand (mean difference = 4.1%, 95% CI, -0.052 to 0.029, P < .001), with handedness explaining 89% of the variation. A 2-way mixed-model analysis of variance determined that there were no interactions between preferred style (bouldering or sport climbing) and MIFS or between ability level (advanced or elite) and MIFS. CONCLUSIONS: Climbers have significant finger flexor strength bilateral asymmetries between their strongest and weakest hand. Moreover, when dominance is controlled, this difference in strength is present, with the dominant hand producing more force. Neither preferred style of climbing nor the ability level of the climbers could explain these asymmetries. As such, practitioners should consider regularly monitoring unilateral strength, aiming to minimize the likelihood of large bilateral asymmetry occurring.

Effects of Caffeine Ingestion on Human Standing Balance: A Systematic Review of Placebo-Controlled Trials.

Caffeine ingestion may influence balance control via numerous mechanisms. Although previously investigated using various study designs and methods, here we aimed to create the first evidence-based consensus regarding the effects of caffeine on the control of upright stance via systematic review (PROSPERO registration CRD42021226939). Embase, PubMed/MEDLINE, SPORTDiscus and Web of Science databases were searched on 27 January 2021 to identify placebo-controlled trials investigating caffeine-induced changes in human standing balance. Reference lists of eligible studies were also searched. Overall, nine studies involving a total of 290 participants were included. All studies were moderate to strong in quality according to the QualSyst tool. Balance-related outcome measures were collected across a range of different participant ages, stances and sensory conditions. The results show that younger participants' balance was generally unaffected by caffeine ingestion. However, a significant balance impairment was observed following caffeine ingestion in all studies involving older participants (average age >65 years). Our results therefore suggest an age-dependent effect of caffeine ingestion on human standing. Further research into this effect is warranted as only one study has directly compared younger and older adults. Nonetheless, an important implication of our findings is that caffeine ingestion may increase fall risk in older adults. Furthermore, based on our findings, caffeine ingestion should be considered as a potential confounding factor when assessing human standing balance, particularly in older adults.

An All-Out Test to Determine Finger Flexor Critical Force in Rock Climbers.

PURPOSE: The fatigue resistance of the finger flexors is known to be a key determinant of climbing performance. This study set out to establish the association between the single all-out assessment of finger flexor critical force (ff-CF) and the impulse above CF (W') on climbing performance (self-reported sport and boulder climbing ability). METHODS: A total of 129 subjects completed an assessment of dominant arm ff-CF, comprised of a series of rhythmic isometric maximum voluntary contractions (CF defined as mean end-test force [in kilograms]; W' impulse above CF [in kilogram second]). RESULTS: The ff-CF protocol resulted in the same force decay to a plateau seen in previous isometric critical torque and critical force tests. Linear regression analysis, adjusting for sex, revealed that CF percentage of body mass explained 61% of sport and 26% of bouldering performance and W' per kilogram body mass explained 7% sport and 34% bouldering performance. A combined model of CF as a percentage of body mass and W' per kilogram body mass, after adjustment for sex differences, was able to explain 66% of sport climbing and 44% of bouldering performance. CONCLUSIONS: The results illustrate the relevance of the CF threshold in describing the fatigue resistance of the finger flexors of rock climbers. Given ff-CF ability to describe a considerable proportion of variance in sport climbing and bouldering ability, the authors expect it to become a common test used by coaches for understanding exercise tolerance and for determining optimal training prescription.

Anthropometry and performance characteristics of recreational advanced to elite female rock climbers.

Despite climbing's popularity and an increasing number of female participants, there are limited anthropometric and performance data for this population. This study compares the characteristics of 55 experienced female climbers, divided into three categories (lower [ADV-L] and higher advanced [ADV-H] and elite [ELT]) based on self-reported ability. Data on climbing experience, body dimensions, body composition, flexibility, lower and upper-body power and finger strength were assessed. ELT climbers differed significantly from the ADV groups in age (Mean Difference [MD] = 8.8-9.8 yrs; despite smaller differences in years climbing MD = 1.6-2.4 yrs), greater climbing and hours training per week (MD = 3.0-3.7 h & MD = 0.9-1.6 h, respectively), and greater upper-body power (MD = 12.9-16.6 cm) and finger strength (MD = 51.6-65.4 N). Linear regression analysis showed finger strength and upper body power to be associated with ability, particularly when adjusting for descriptive and anthropometric variables (finger strength R2 = 53% and 45%; upper-body power R2 = 60% and 39% for boulder and sport, respectively). The findings support the importance of finger strength and upper-body power; changes in female anthropometric data over the last decade provide insight into the changing nature of the sport.

A Novel Tool for the Assessment of Sport Climbers' Movement Performance.

PURPOSE: To assess the validity and reliability of a novel movement-performance assessment tool for climbing/sport climbing. METHODS: First, salient climbing movement-performance factors were identified through an iterative consultation process with 10 expert climbing coaches; the resulting Climber's Movement Performance Assessment Tool (CM-PAT) contained 14 items in 5 categories. Second, 61 intermediate to advanced climbers ascended a single route, which was video recorded. Subsequently, 4 experienced (>10 y coaching) coaches used the CM-PAT to observe and score the climbers' performance. Interrater reliability and comparisons with existing measures of climbing performance (6-mo self-reported ability, success and failure, climbing pace [m·min-1], and geometric entropy) were made. RESULTS: Intraclass correlation coefficient (2,k) for the 4 raters demonstrated excellent reliability (>.81) between observers and good to excellent test-retest reliability (.71-.91). Pearson correlations between self-reported ability and CM-PAT scores explained 61% of the variance in self-reported climbing performance compared with 16% for geometric entropy and 52% for climbing pace. Considering differences in successful and unsuccessful climbers, the CM-PAT (P < .0005; d = 2.14), geometric entropy (P = .014; d = 0.67), and pace (P < .0005; d = 1.88) were able to differentiate between groups. CONCLUSIONS: The CM-PAT is the first sport climbing performance observational instrument to be developed through a thorough iterative process with expert coaches. Excellent interrater and test-retest reliability and excellent agreement with self-reported ability and with existing quantitative measures of performance support its recommendation for use in coaching and research contexts. Notably, a key advantage over existing measures is the identification of coachable elements of performance.

The Determination of Finger-Flexor Critical Force in Rock Climbers.

Purpose: To determine if the mathematical model used for the estimation of critical force (CF) and the energy store component W' are applicable to intermittent isometric muscle actions of the finger flexors of rock climbers, using a multisession test. As a secondary aim, the agreement of estimates of CF and W' from a single-session test was also determined. The CF was defined as the slope coefficient, and W' was the intercept of the linear relationship between total "isometric work" (Wlim) and time to exhaustion (Tlim). Methods: Subjects performed 3 (separated by either 20 min or >24 h) tests to failure using intermittent isometric finger-flexor contractions at 45%, 60%, and 80% of their maximum voluntary contraction. Results: Force plotted against Tlim displayed a hyperbolic relationship; correlation coefficients of the parameter estimates from the work-time CF model were consistently very high (R2 > .94). Climbers' mean CF was 425.7 (82.8) N (41.0% [6.2%] maximum voluntary contraction) and W' was 30,882 (11,820) N·s. Good agreement was found between the single-session and multisession protocol for CF (intraclass correlation coefficient [ICC3,1] = .900; 95% confidence interval, .616-.979), but not for W' (ICC3,1 = .768; 95% confidence interval, .190-.949). Conclusions: The results demonstrated the sensitivity of a simple test for the determination of CF and W', using equipment readily available in most climbing gyms. Although further work is still necessary, the test of CF described is of value for understanding exercise tolerance and to determine optimal training prescription to monitor improvements in the performance of the finger flexors.

Characteristics explaining performance in downhill mountain biking.

PURPOSE: To identify physiological, psychological, and skill characteristics that explain performance in downhill (DH) mountain-bike racing. METHODS: Four studies were used to (1) identify factors potentially contributing to DH performance (using an expert focus group), (2) develop and validate a measure of rider skill (using video analysis and expert judge evaluation), (3) evaluate whether physiological, psychological, and skill variables contribute to performance at a DH competition, and (4) test the specific contribution of aerobic capacity to DH performance. RESULTS: STUDY 1 identified aerobic capacity, handgrip endurance, anaerobic power, rider skill, and self-confidence as potentially important for DH. In study 2 the rider-skill measure displayed good interrater reliability. Study 3 found that rider skill and handgrip endurance were significantly related to DH ride time (ß=-0.76 and -0.14, respectively; R2=.73), with exploratory analyses suggesting that DH ride time may also be influenced by self-confidence and aerobic capacity. Study 4 confirmed aerobic capacity as an important variable influencing DH performance (for a DH ride, mean oxygen uptake was 49±5 mL·kg(-1)·min(-1), and 90% of the ride was completed above the 1st ventilatory threshold). CONCLUSIONS: In order of importance, rider skill, handgrip endurance, self-confidence, and aerobic capacity were identified as variables influencing DH performance. Practically, this study provides a novel assessment of rider skill that could be used by coaches to monitor training and identify talent. Novel intervention targets to enhance DH performance were also identified, including self-confidence and aerobic capacity.