Importance of shoulder girdle and finger flexor muscle endurance in advanced male climbers.

Aim: This study aimed to: (a) assess the relationships between climbing performance and finger and shoulder girdle muscle endurance; and (b) provide evidence on the validity of the specialized exercise tests used for the purpose. Materials and methods: 28 male sport climbers (climbing ability 23 ± 2.43 IRCRA scale) performed four tests muscle failure, including two-finger hang tests (using 2.5 and 4 cm holds) and two variants of pull-up exercises (classical pull-ups and a combination of dynamic and isometric actions - the so-called Edlinger). Climbing performance and test results were subjected to correlation, taxonomic and regression analysis. Results: The correlations between the results from all tests and climbing performance were notably strong ( r between 0.54 and 0.61) and statistically significant ( p < 0.05 ). The taxonomic analysis indicated that the two variants of each test type reflect two different latent variables 2.5 cm and 4 cm finger hang durations were highly correlated ( r = 0.76 , p < 0.01 ). A similar correlation was found between the results from the pull-up tests ( r = 0.72 , p < 0.01 ). Thus, the finger hang and pull-up test results were determined to a high extent (43% and 49%, respectively) by factors that cannot be assessed when only one test of each type is used. The regression model of the two-finger tests allowed individual endurance profiles to be assessed. Conclusions: The muscular endurance of the elbow flexors and shoulder girdle muscles predicts climbing performance within the specific sport level studied to a comparable degree as finger flexor endurance.The use of two variants of a test intended to assess one physical ability provided important details on a climber's fitness.

The Connection Between Resistance Training, Climbing Performance, and Injury Prevention.

BACKGROUND: Climbing is an intricate sport composed of various disciplines, holds, styles, distances between holds, and levels of difficulty. In highly skilled climbers the potential for further strength-specific adaptations to increase performance may be marginal in elite climbers. With an eye on the upcoming 2024 Paris Olympics, more climbers are trying to maximize performance and improve training strategies. The relationships between muscular strength and climbing performance, as well as the role of strength in injury prevention, remain to be fully elucidated. This narrative review seeks to discuss the current literature regarding the effect of resistance training in improving maximal strength, muscle hypertrophy, muscular power, and local muscular endurance on climbing performance, and as a strategy to prevent injuries. MAIN BODY: Since sport climbing requires exerting forces against gravity to maintain grip and move the body along the route, it is generally accepted that a climber`s absolute and relative muscular strength are important for climbing performance. Performance characteristics of forearm flexor muscles (hang-time on ledge, force output, rate of force development, and oxidative capacity) discriminate between climbing performance level, climbing styles, and between climbers and non-climbers. Strength of the hand and wrist flexors, shoulders and upper limbs has gained much attention in the scientific literature, and it has been suggested that both general and specific strength training should be part of a climber`s training program. Furthermore, the ability to generate sub-maximal force in different work-rest ratios has proved useful, in examining finger flexor endurance capacity while trying to mimic real-world climbing demands. Importantly, fingers and shoulders are the most frequent injury locations in climbing. Due to the high mechanical stress and load on the finger flexors, fingerboard and campus board training should be limited in lower-graded climbers. Coaches should address, acknowledge, and screen for amenorrhea and disordered eating in climbers. CONCLUSION: Structured low-volume high-resistance training, twice per week hanging from small ledges or a fingerboard, is a feasible approach for climbers. The current injury prevention training aims to increase the level of performance through building tolerance to performance-relevant load exposure and promoting this approach in the climbing field.

Comparison of finger flexor resistance training, with and without blood flow restriction, on perceptional and physiological responses in advanced climbers.

This study compared perceptional and physiological responses of finger flexor exercise performed with free flow and blood flow restriction (BFR). Thirteen male advanced climbers completed three sessions of finger flexor resistance exercise at (1) 40% of MVC (Low) and (2) 75% of MVC (High) and (3) BFR at 40% of MVC (Low + BFR) in a randomized and counterbalanced order. Rate of perceived exertion for effort (RPE) and discomfort (RPD), session pleasure/displeasure (sPDF), exercise enjoyment (EES), lactate concentration and oxygen saturation were recorded after the last set. Both low-intensity sessions induced higher RPD than High (p = 0.018-0.022, ES = 1.01-1.09) and High was perceived as more enjoyable than Low-BFR (p = 0.031, ES = 1.08). No differences were found for RPE or sPDF (p = 0.132-0.804). Lactate was elevated more after High than the Low-sessions (p < 0.001, ES = 1.88-2.08). Capillary oxygen saturation was lower after Low + BFR compared to the other sessions (p = 0.031, ES = 1.04-1.27). Finally, the exercise volume was greater in Low compared to High (p = 0.022, ES = 1.14) and Low + BFR (p = 0.020, ES = 0.77). In conclusion, among advanced male climbers, performing Low + BFR led to a similar exercise volume but was perceived as more discomforting and less enjoyable compared to High. The Low session yielded similar responses as the Low + BFR but required a much greater exercise volume.

Acute Effects of Whole-Body Vibration on Resting Metabolic Rate and Substrate Utilisation in Healthy Women.

The aim of the study was to determine the acute effects of single-whole-body vibration (WBV) on resting metabolic rate (RMR) and carbohydrate−lipid profile of blood in young, healthy women. The participants, in a randomised controlled crossover study, participated in two trials: WBV and a vibration simulation (placebo). The WBV was performed in the prone position and cycloidal-oscillatory vibration was used. The RMR measurement (calorimetry) was performed: before the WBV, during WBV, immediately after the completion of WBV, and 1 h after the completion of WBV. For biochemical analyses, venous blood was collected. During WBV, there was a significant increase in RMR compared to baseline. Immediately after and 1 h following the end of the WBV, RMR was close to baseline levels (p > 0.05). The increased energy expenditure resulted from the increased utilisation of carbohydrates and proteins during the vibration. In the placebo condition, there were no significant changes over time in the level of the studied indices during calorimetry. The WBV had no significant effects on the level of glucose in the blood. The applied vibration did not significantly affect the concentration of the analysed lipid indices, which were within the physiological norms for all measurements. Results indicate the need for further research to establish the physiological mechanisms underlying the observed effects of WBV on resting metabolic rate.

Muscle strength and endurance in high-level rock climbers.

The relative importance of key performance factors is poorly studied in high-level climbers. This study aimed to (1) determine the role of forearm muscle strength and endurance in high-level rock climbing, (2) and provide suitable dynamometric test parameters for muscle endurance assessment in high-level climbers. Six higher elite (redpoint Fr.9a) and eight elite/advanced (redpoint Fr.8a+) climbers performed one finger flexor maximal strength test and three finger endurance tests: a 30 s all-out test and a continuous and intermittent test at 60% of maximal voluntary contraction. Higher elite climbers had higher (p < 0.05) maximal strength, all-out test average force and continuous test force-time integral (all relative to body mass) than the elite/advanced climbers. These parameters correlated significantly (p < 0.05) with climbing performance, which has not been observed so far for continuous test scores. Unlike in previous research, intermittent test force-time integral neither distinguished climbing ability groups nor correlated significantly with climbing performance. Nevertheless, regression models comprising of intermittent and maximal strength test scores more strongly determined climbing performance than models including continuous or all-out test scores. Intermittent muscle endurance is among the performance factors in difficult rock climbing but appears to be less important than maintaining high forces during sustained muscle contractions.

Climbing-Specific Exercise Tests: Energy System Contributions and Relationships With Sport Performance.

PURPOSE: The aim of the study was to evaluate distinct performance indicators and energy system contributions in 3 different, new sport-specific finger flexor muscle exercise tests. METHODS: The tests included the maximal strength test, the all-out test (30 s) as well as the continuous and intermittent muscle endurance test at an intensity equaling 60% of maximal force, which were performed until target force could not be maintained. Gas exchange and blood lactate were measured in 13 experienced climbers during, as well as pre and post the test. The energy contribution (anaerobic alactic, anaerobic lactic, and aerobic) was determined for each test. RESULTS: The contribution of aerobic metabolism was highest during the intermittent test (59.9 ± 12.0%). During continuous exercise, this was 28.1 ± 15.6%, and in the all-out test, this was 19.4 ± 8.1%. The contribution of anaerobic alactic energy was 27.2 ± 10.0% (intermittent), 54.2 ± 18.3% (continuous), and 62.4 ± 11.3% (all-out), while anaerobic lactic contribution equaled 12.9 ± 6.4, 17.7 ± 8.9, and 18.2 ± 9.9%, respectively. CONCLUSION: The combined analysis of performance predictors and metabolic profiles of the climbing test battery indicated that not only maximal grip force, but also all-out isometric contractions are equally decisive physical performance indices of climbing performance. Maximal grip force reflects maximal anaerobic power, while all-out average force and force time integral of constant isometric contraction at 60% of maximal force are functional measures of anaerobic capacity. Aerobic energy demand for the intermittent exercise is dominated aerobic re-phosphorylation of high-energy phosphates. The force-time integral from the intermittent test was not decisive for climbing performance.

Reliability and Validity of Finger Strength and Endurance Measurements in Rock Climbing.

PURPOSE: An advanced system for the assessment of climbing-specific performance was developed and used to: (a) investigate the effect of arm fixation (AF) on construct validity evidence and reliability of climbing-specific finger-strength measurement; (b) assess reliability of finger-strength and endurance measurements; and (c) evaluate the relationship between finger flexor all-out test scores and climbing ability. METHODS: To determine the effect of AF, 22 male climbers performed 2 maximal strength and all-out tests with AF (shoulder and elbow flexed at 90°) and without AF (shoulder flexed at 180° and elbow fully extended). To determine reliability, 9 male climbers completed 2 maximal strength tests with and without AF and an all-out and intermittent test without AF. RESULTS: The maximal strength test without AF more strongly determined climbing ability than the test with AF (r2 = .48 and r2 = .42 for sport climbing; r2 = .66 and r2 = .42 for bouldering, respectively). Force and time variables were highly reliable; the rate of force development and fatigue index had moderate and low reliability. The maximal strength test with AF provided slightly higher reliability than without AF (intraclass correlation coefficient [ICC] = 0.94, ICC = 0.88, respectively). However, smaller maximal forces were achieved during AF (484 ± 112 N) than without AF (546 ± 132 N). All-out test average force had sufficiently high reliability (ICC = 0.92) and a relationship to sport climbing (r2 = .42) and bouldering ability (r2 = .58). CONCLUSION: Finger strength and endurance measurements provided sufficient construct validity evidence and high reliability for time and force parameters. Arm fixation provides more reliable results; however, the position without AF is recommended as it is more related to climbing ability.

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

This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time-force characteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve the target force during intermittent testing in rock climbers. Twenty-two participants undertook three finger flexor endurance tests at 60% of their maximal voluntary contraction until failure. Performances of a sustained contraction and two intermittent contractions, each with different recovery strategies, were analysed by time-force parameters and near-infrared spectroscopy. Recovery with shaking of the forearm beside the body led to a significantly greater intermittent test time (↑ 22%, P < .05), force-time integral (↑ 28%, P < .05) and faster muscle re-oxygenation (↑ 32%, P < .05), when compared to the hand over hold condition. Further, the ratio of intermittent to continuous test time distinguished specific aerobic muscular adaptations among sport climbers (2.02), boulderers (1.74) and lower grade climbers (1.25). Lower grade climbers and boulderers produced shorter duration contractions due to the slower development of target force during the intermittent test, indicating worse kinaesthetic differentiation. Both the type of recovery and climbing discipline determined muscle re-oxygenation and intermittent performance in rock climbers.

A sport-specific upper-body ergometer test for evaluating submaximal and maximal parameters in elite rock climbers.

UNLABELLED: Traditional treadmill or bicycle ergometry neglects the upper-body musculature that predominantly limits or terminates rock-climbing performance (ie, the inability to continually pull up one's body mass or "hang on"). PURPOSE: To develop an incremental maximal upper-body ergometer test (UBT) to evaluate climbers' aerobic fitness and sport-specific work capacity and to compare these results with a traditional treadmill protocol. METHODS: Eleven elite sport climbers (best redpoint grade Fr.8b) performed a UBT on a vertically mounted rowing ergometer and, on a separate occasion, performed a maximal incremental treadmill test (TMT). Cardiorespiratory parameters were measured continuously. Lactate (La) samples were collected. RESULTS: Peak oxygen consumption (VO2peak) and heart rate in UBT and TMT were 34.1 ± 4.1 vs 58.3 ± 2.6 mL · min-1 · kg-1 and 185 ± 8 vs 197 ± 8 beats/min, respectively, and both variables were of significantly lower magnitude during UBT (P < .001). End-of-test La levels for UBT (11.9 ± 1.7 mmol/L) and TMT (12.3 ± 2.5 mmol/L) were similar (P = .554). Treadmill VO2peak was not correlated with either upper-body (UB) VO2peak (P = .854) or redpoint and on-sight climbing grade ability (P > .05). UB VO2peak and peak power output per kg body mass were both strongly correlated (P < .05) with climbing grade ability. The highest correlation coefficient was calculated between current on-sight grade and UB VO2peak (r = .85, P = .001). CONCLUSION: UBT aerobic- and work-capacity results were strongly correlated to climbing-performance variables and reflected sport-specific fatigue, and TMT results were not. UBT is preferred to TMT to test and monitor dedicated and elite rock climbers' training status.

Hepatitis C virus recombinants are rare even among intravenous drug users.

Systematic studies of the circulation of hepatitis C virus (HCV) recombinants in different parts of the world have been initiated only recently, and no detailed information on this subject is available. The aim of the current investigation was to determine the frequency of HCV recombinants in intravenous drug users (IVDU) from two European countries. HCV RNA from serum samples was tested by RT-PCR with primers derived from the core and NS5B regions with subsequent sequencing and genotype assignment. The 118 samples from Germany (100%) and 45 out of 47 (96%) sera from Russia demonstrated concordant genotyping results. In the two genotype discrepant sera from Russia 2k/1b recombinants were identified. In order to test the hypothesis that the individuals from the IVDU group might be multiply exposed to various genotypes, 145 out of 165 genotyped serum samples, which were found to be positive for anti-NS4 antibodies, were serotyped with the Murex HCV serotyping kit that is based on detection of antibodies to type-specific peptides derived from the NS4 proteins of different HCV genotypes. Discrepancy in genotype and serotype attributions was observed in 11% cases. Retesting of 99 type 1a or 3a samples with a set of type- and subtype-specific primers revealed the presence of a mixed infection only in one case (1a/3a). Thus, the cases of the mixed infection with different HCV genotypes as well as the recombinant forms of HCV are very rare even in such a highly exposed group as IVDU.

D2: major subgenotype of hepatitis B virus in Russia and the Baltic region.

Complete or almost complete hepatitis B virus (HBV) genomes were sequenced for 13 genotype A and 42 genotype D strains from the former USSR. The strains were classifiable within subgenotypes A2, D1, D2 and D3. Comparison of the deduced gene products for the four ORFs of 89 genotype D strains revealed 27 subgenotype-specific residues, and a region spanning residues 58-128 in the spacer region of the P gene could be used to distinguish between D1 and D4. This enabled the allocation to subgenotype of strains with partially sequenced genomes. D2 was dominating, while D3 was found in low frequency in the whole region. D1 was most prevalent in the Middle Asian Republics. Mean inter-subgenotype divergences between D1 and D2, D1 and D3 and D2 and D3 were 2.7, 3.4 and 3.4 %, respectively. The intra-subgenotype divergence was 0.4, 1.1, 1.0 and 1.8 % for A2, D1, D2 and D3, respectively. All D1 and D3 strains encoded subtype ayw2, whereas most D2 strains encoded ayw3. Two D2 strains encoded ayw4. Strains with identical S genes were closely related at the level of complete genomes and formed geographically specific clades with low intraclade divergences, possibly indicating past iatrogenic spread. It is not clear whether the finding of four subgenotypes in the area corresponds to separate introductions of the virus or to previous population migrations into the area. An earlier introduction of D3 compared with D2 was supported by its higher intra-subgenotype divergence, while the lower divergence within D1 is probably due to a more recent emergence.

Immunogenicity of a chimeric hepatitis A virus (HAV) carrying the HIV gp41 epitope 2F5.

Its stable particle structure combined with its high immunogenicity makes the hepatitis A virus (HAV) a perfect carrier to expose foreign epitopes to the host immune system. In an earlier report [Beneduce, F., Kusov, Y., Klinger, M., Gauss-Müller, V., Morace, G., 2002. Chimeric hepatitis A virus particles presenting a foreign epitope (HIV gp41) at their surface. Antiviral Res. 55, 369-377] chimeric virus-like particles (HAV-gp41) were described that carried at their surface the dominant gp41 epitope 2F5 (2F5e) of the human immunodeficiency virus HIV-1. Extending this work, we now report that chimeric virus HAV-gp41 replicates in HAV-susceptible cells as well as in non-human primates. Infected marmosets developed both an anti-HAV and anti-2F5 epitope immune response. Furthermore, an HIV-neutralizing antibody response was elicited in guinea pigs immunized with HAV-gp41 chimeric particles. The results demonstrate that the replication-competent chimeric HAV-gp41 can serve as either a live or a subunit vaccine for eliciting of antibodies directed against a foreign antigenic epitope.

Acute GB virus B infection of marmosets is accompanied by mutations in the NS5A protein.

GBV-B, a member of the Flaviviridae family of viruses, is the virus most closely related to HCV, and GBV-B infection in tamarin monkeys might represent a valuable surrogate animal model of HCV infection. In the current study, GBV-B was successfully transmitted to two marmosets (Callithrix jaccus). The infection resulted in viremia of 14- and 17-week duration, respectively, and was accompanied by elevation of isocitrate dehydrogenase activity. These data confirm that marmosets might represent an attractive model for GBV-B infection. The sequence of GBV-B NS5A, which was previously reported to have one of the highest mutation rates during infection in tamarins, was determined for viruses recovered from the inoculum and from marmoset blood samples obtained at weeks 1, 8, and 14 post inoculation in one marmoset and at weeks 2, 8, and 17 post inoculation in the other marmoset. In both animals, we detected four substitutions (R1945K, K2052G, F2196L, and G2268E), in the virus recovered immediately before viral clearance. Interestingly, two of these mutations (F2196L and G2268E) were described recently for viruses recovered from persistently infected tamarins. Appearance of these mutations presumably reflects a mechanism of immune escape rather than adaptation of the virus to a new host.