RALDH Activity Induced by Bacterial/Fungal Pathogens in CD16+ Monocyte-Derived Dendritic Cells Boosts HIV Infection and Outgrowth in CD4+ T Cells.

HIV reservoirs persist in gut-homing CD4+ T cells of people living with HIV and receiving antiretroviral therapy, but the antigenic specificity of such reservoirs remains poorly documented. The imprinting for gut homing is mediated by retinoic acid (RA), a vitamin A-derived metabolite produced by dendritic cells (DCs) exhibiting RA-synthesizing (RALDH) activity. RALDH activity in DCs can be induced by TLR2 ligands, such as bacterial peptidoglycans and fungal zymosan. Thus, we hypothesized that bacterial/fungal pathogens triggering RALDH activity in DCs fuel HIV reservoir establishment/outgrowth in pathogen-reactive CD4+ T cells. Our results demonstrate that DCs derived from intermediate/nonclassical CD16+ compared with classical CD16- monocytes exhibited superior RALDH activity and higher capacity to transmit HIV infection to autologous Staphylococcus aureus-reactive T cells. Exposure of total monocyte-derived DCs (MDDCs) to S. aureus lysates as well as TLR2 (zymosan and heat-killed preparation of Listeria monocytogenes) and TLR4 (LPS) agonists but not CMV lysates resulted in a robust upregulation of RALDH activity. MDDCs loaded with S. aureus or zymosan induced the proliferation of T cells with a CCR5+integrin ß7+CCR6+ phenotype and efficiently transmitted HIV infection to these T cells via RALDH/RA-dependent mechanisms. Finally, S. aureus- and zymosan-reactive CD4+ T cells of antiretroviral therapy-treated people living with HIV carried replication-competent integrated HIV-DNA, as demonstrated by an MDDC-based viral outgrowth assay. Together, these results support a model in which bacterial/fungal pathogens in the gut promote RALDH activity in MDDCs, especially in CD16+ MDDCs, and subsequently imprint CD4+ T cells with gut-homing potential and HIV permissiveness. Thus, nonviral pathogens play key roles in fueling HIV reservoir establishment/outgrowth via RALDH/RA-dependent mechanisms that may be therapeutically targeted.

Bilateral deficit in the countermovement jump and its associations with judo-specific performance.

This study aimed to describe the bilateral deficit (BLD) during the countermovement jump (CMJ) in judo athletes and determine the relationship between the BLD and judo-specific performance. Fourteen male judo athletes participated. Athletes performed three specific judo tests, Maximal Sprint Speed Judo Test, Maximal Aerobic Speed Judo Test and Special Judo Fitness Test (SJFT), and double- and single-leg CMJ. The following CMJ variables were used: jump height (JH), mean (MPO) and peak (PPO) power output, peak force (PF), peak velocity (PV) and impulse (IMP). The Pearson's or Spearman's test were used (p < 0.05). The results show that the BLD is found in all CMJ parameters (20 to 31%). Negative correlations between first set of SJFTTT (total throws) and BLD in PF (r = -0.60; p= 0.022) and between the second set of SJFTTT and BLD in MPO (r= -0.74;p = 0.002), PV (r =-0.59;p = 0.025) and IMP (r =-0.55; p = 0.040) were found. Also, negative correlations between SJFTTT and the BLD in all CMJ parameters (r= -0.53 to -0.85; p < 0.05) were found. Higher values of BLD are related to poor SJFTTT performance.

Is Vertical Jump Height an Indicator of Athletes' Power Output in Different Sport Modalities?

Kons, RL, Ache-Dias, J, Detanico, D, Barth, J, and Dal Pupo, J. Is vertical jump height an indicator of athletes' power output in different sports modalities? J Strength Cond Res 32(3): 708-715, 2018-This study aimed to identify whether the ratio standard is adequate for the scaling of peak power output (PPO) for body mass (BM) in athletes of different sports and to verify classification agreement for athletes involved in different sports using PPO scaled for BM and jump height (JH). One hundred and twenty-four male athletes divided into 3 different groups-combat sports, team sports, and runners-participated in this study. Participants performed the countermovement jump on a force plate. Peak power output and JH were calculated from the vertical ground reaction force. We found different allometric exponents for each modality, allowing the use of the ratio standard for team sports. For combat sports and runners, the ratio standard was not considered adequate, and therefore, a specific allometric exponent for these 2 groups was found. Significant correlations between adjusted PPO for BM (PPOADJ) and JH were found for all modalities, but it was higher for runners (r = 0.81) than team and combat sports (r = 0.63 and 0.65, respectively). Moderate agreement generated by the PPOADJ and JH was verified in team sports (k = 0.47) and running (k = 0.55) and fair agreement in combat sports (k = 0.29). We conclude that the ratio standard seems to be suitable only for team sports; for runners and combat sports, an allometric model seems adequate. The use of JH as an indicator of power output may be considered reasonable only for runners.

Effect of Jump Interval Training on Kinematics of the Lower Limbs and Running Economy.

Ache-Dias, J, Pupo, JD, Dellagrana, RA, Teixeira, AS, Mochizuki, L, and Moro, ARP. Effect of jump interval training on kinematics of the lower limbs and running economy. J Strength Cond Res 32(2): 416-422, 2017-This study analyzed the effects of the addition of jump interval training (JIT) to continuous endurance training (40-minute running at 70% of peak aerobic velocity, 3 times per week for 4 weeks) on kinematic variables and running economy (RE) during submaximal constant-load running. Eighteen recreational runners, randomized into control group (CG) or experimental group (EG) performed the endurance training. In addition, the EG performed the JIT twice per week, which consisted of 4-6 bouts of continuous vertical jumping (30 seconds) with 5-minute intervals. The oxygen consumption (V[Combining Dot Above]O2) during the submaximal test (performed at 9 km·h) was similar before (EG: 38.48 ± 2.75 ml·kg·min; CG: 36.45 ± 2.70 ml·kg·min) and after training (EG: 37.42 ± 2.54 ml·kg·min; CG: 35.81 ± 3.10 ml·kg·min). No effect of training, group, or interaction (p > 0.05) was found for RE. There was no interaction or group effect for the kinematic variables (p > 0.05). Most of the kinematic variables had a training effect for both groups (support time [p ≤ 0.05]; step rate [SR; p ≤ 0.05]; and step length [SL; p ≤ 0.05]). In addition, according to the practical significance analysis (percentage chances of a better/trivial/worse effect), important effects in leg stiffness (73/25/2), vertical stiffness (73/25/2), SR (71/27/2), and SL (64/33/3) were found for the EG. No significant relationship between RE and stiffness were found for EG and CG. In conclusion, the results suggest that JIT induces important changes in the kinematics of the lower limbs of recreational runners, but the changes do not affect RE.

The fatigue effect of a simulated futsal match protocol on sprint performance and kinematics of the lower limbs.

This study aimed to investigate the fatigue effects induced by a futsal-specific protocol (FIRP) on sprint performance and the kinematics of the lower limbs. Twenty-one futsal players participated in this study and performed a protocol to simulate the futsal demands. At pre-protocol, half-time and post-protocol, the athletes performed 10-m sprints that were recorded for kinematic analysis. Continuous relative phase (CRP) was calculated to assess the inter-segmental coordination. In addition, vertical (KVERT) and leg (KLEG) stiffness were calculated. Analysis of variance (ANOVA) for repeated measures was used (P < 0.05). The main results showed that sprint time increased (P < 0.01) post-protocol when compared to pre- and half-time conditions. Lower values of the step rate (P = 0.01) and higher values of the leg angular velocity (P = 0.02) were verified at the end of the FIRP. The CRP of thigh-leg and leg-foot and the stiffness did not change over the protocol. In addition, the high correlation of CRP between the conditions revealed no changes in coordination pattern. We concluded that futsal related-fatigue induced a decrement on sprint time, changing the kinematics of the lower limbs (decreasing step rate and increasing leg angular velocity). However, neither stiffness nor intersegment coordination during sprints was affected by fatigue.

Power Output Prediction From Jump Height and Body Mass Does Not Appropriately Categorize or Rank Athletes.

The purposes of this study were (a) to verify the agreement of categorization and ranks based on the actual power output measured by a force plate (PPact) and the estimated power output (PPest) from jump height and body mass (BM), and (b) to verify whether the ratio standard is adequate to scale the PPact for BM. The countermovement jumps of 309 male athletes were analyzed. The athletes were first categorized into tertiles (superior, intermediate, and inferior) according to PPact and PPest. After that the athletes were ranked (highest to lowest power output) according to PPact and PPest. The PPest equation explained 81% of PPact variance (standard error of estimate = 277.4 W). The PPest (3,757.1 ± 579.8 W) displayed similar mean values compared with PPact (3,757.1 ± 642.3 W). However, the agreement between the categories generated by PPact and PPest was only moderate (k = 0.6; p < 0.01), and in the intermediate tertile, the categorization differs 38.8%. The agreement between the ranks analyzed from a Bland-Altman plot shows bias zero, but a wide limits of agreement (81 ranks; 26.2%). For the PPact scaling, the ratio standard may be considered as an adequate method for removing the BM effect, considering the lack of correlation between the scaled PPact (PPact/BM) and BM, and also the confirmation of Tanner's special circumstance. In conclusion, our findings indicate that the athlete's power output was not appropriately categorized or ranked when using PPest. Furthermore, the use of the scaled PPact is recommended to fairly compare athletes with different BMs.

Retinoic acid enhances HIV-1 reverse transcription and transcription in macrophages via mTOR-modulated mechanisms.

The intestinal environment facilitates HIV-1 infection via mechanisms involving the gut-homing vitamin A-derived retinoic acid (RA), which transcriptionally reprograms CD4+ T cells for increased HIV-1 replication/outgrowth. Consistently, colon-infiltrating CD4+ T cells carry replication-competent viral reservoirs in people with HIV-1 (PWH) receiving antiretroviral therapy (ART). Intriguingly, integrative infection in colon macrophages, a pool replenished by monocytes, represents a rare event in ART-treated PWH, thus questioning the effect of RA on macrophages. Here, we demonstrate that RA enhances R5 but not X4 HIV-1 replication in monocyte-derived macrophages (MDMs). RNA sequencing, gene set variation analysis, and HIV interactor NCBI database interrogation reveal RA-mediated transcriptional reprogramming associated with metabolic/inflammatory processes and HIV-1 resistance/dependency factors. Functional validations uncover post-entry mechanisms of RA action including SAMHD1-modulated reverse transcription and CDK9/RNA polymerase II (RNAPII)-dependent transcription under the control of mammalian target of rapamycin (mTOR). These results support a model in which macrophages residing in the intestine of ART-untreated PWH contribute to viral replication/dissemination in an mTOR-sensitive manner.

Stiffness, intralimb coordination, and joint modulation during a continuous vertical jump test.

This study analysed the modulation of jump performance, vertical stiffness as well as joint and intralimb coordination throughout a 30-s vertical jump test. Twenty male athletes performed the test on a force plate while undergoing kinematic analysis. Jump height, power output, ground contact time, vertical stiffness, maximum knee and hip flexion angles, and coordination by continuous relative phase (CRP) were analysed. Analysis of variance was used to compare variables within deciles, and t-tests were used to compare CRP data between the initial and final jumps. Results showed reduction in jump height, power output, and vertical stiffness, with an increase in contact time found during the test. Maximum knee and hip flexion angles declined, but hip angle decreased earlier (10-20% of the test) than knee angle (90-100%). No changes were observed in CRP for thigh-leg coupling when comparing initial and final jumps, but the trunk-thigh coupling was more in-phase near the end of the test. We conclude that fatigue causes reduction in jump performance, as well as changes in stiffness and joint angles. Furthermore, changes in intralimb coordination appear at the last 10% of the test, suggesting a neuromotor mechanism to counterbalance the loss of muscle strength.

Identification of aryl hydrocarbon receptor as a barrier to HIV-1 infection and outgrowth in CD4+ T cells.

The aryl hydrocarbon receptor (AhR) regulates Th17-polarized CD4+ T cell functions, but its role in HIV-1 replication/outgrowth remains unknown. Genetic (CRISPR-Cas9) and pharmacological inhibition reveal AhR as a barrier to HIV-1 replication in T cell receptor (TCR)-activated CD4+ T cells in vitro. In single-round vesicular stomatitis virus (VSV)-G-pseudotyped HIV-1 infection, AhR blockade increases the efficacy of early/late reverse transcription and subsequently facilitated integration/translation. Moreover, AhR blockade boosts viral outgrowth in CD4+ T cells of people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Finally, RNA sequencing reveals genes/pathways downregulated by AhR blockade in CD4+ T cells of ART-treated PLWH, including HIV-1 interactors and gut-homing molecules with AhR-responsive elements in their promoters. Among them, HIC1, a repressor of Tat-mediated HIV-1 transcription and a tissue-residency master regulator, is identified by chromatin immunoprecipitation as a direct AhR target. Thus, AhR governs a T cell transcriptional program controlling viral replication/outgrowth and tissue residency/recirculation, supporting the use of AhR inhibitors in "shock and kill" HIV-1 remission/cure strategies.

Effects of Plyometric Training on Physical Performance: An Umbrella Review.

BACKGROUND: Plyometric training can be performed through many types of exercises involving the stretch-shortening cycle in lower limbs. In the last decades, a high number of studies have investigated the effects of plyometric training on several outcomes in different populations. OBJECTIVES: To systematically review, summarize the findings, and access the quality of published meta-analyses investigating the effects of plyometric training on physical performance. DESIGN: Systematic umbrella review of meta-analyses. DATA SOURCES: Meta-analyses were identified using a systematic literature search in the databases PubMed/MEDLINE, Scopus, SPORTDiscus, Web of Science, Cochrane Library and Scielo. ELIGIBILITY CRITERIA FOR SELECTING META-ANALYSES: Meta-analyses that examined the effects of plyometric training on physical fitness in different populations, age groups, and sex. RESULTS: Twenty-nine meta-analyses with moderate-to-high methodological quality were included in this umbrella review. We identified a relevant weakness in the current literature, in which five meta-analyses included control group comparisons, while 24 included pre-to-post-effect sizes. Trivial-to-large effects were found considering the effects of plyometric training on physical performance for healthy individuals, medium-trivial effects for the sports athletes' groups and medium effects for different sports athletes' groups, age groups, and physical performance. CONCLUSION: The available evidence indicates that plyometric training improves most related physical fitness parameters and sports performance. However, it is important to outline that most meta-analyses included papers lacking a control condition. As such, the results should be interpreted with caution. PROSPERO number: CRD42020217918.

Validity of two methods for estimation of vertical jump height.

The objectives of this study were (a) to determine the concurrent validity of the flight time (FT) and double integration of vertical reaction force (DIF) methods in the estimation of vertical jump height with the video method (VID) as reference; (b) to verify the degree of agreement among the 3 methods; (c) to propose regression equations to predict the jump height using the FT and DIF. Twenty healthy male and female nonathlete college students participated in this study. The experiment involved positioning a contact mat (CTM) on the force platform (FP), with a video camera 3 m from the FP and perpendicular to the sagittal plane of the subject being assessed. Each participant performed 15 countermovement jumps with 60-second intervals between the trials. Significant differences were found between the jump height obtained by VID and the results with FT (p ≤ 0.01) and DIF (p ≤ 0.01), showing that the methods are not valid. Additionally, the DIF showed a greater degree of agreement with the reference method than the FT did, and both presented a systematic error. From the linear regression test was determined the prediction equations with a high degree of linearity between the methods VID vs. DIF (R = 0.988) and VID vs. FT (R = 0.979). Therefore, the prediction equations suggested may allow coaches to measure the vertical jump performance of athletes by the FT and DIF, using a CTM or an FP, which represents more practical and viable approaches in the sports field; comparisons can then be made with the results of other athletes evaluated by VID.

The Biology of Vasopressin.

Vasopressins are evolutionarily conserved peptide hormones. Mammalian vasopressin functions systemically as an antidiuretic and regulator of blood and cardiac flow essential for adapting to terrestrial environments. Moreover, vasopressin acts centrally as a neurohormone involved in social and parental behavior and stress response. Vasopressin synthesis in several cell types, storage in intracellular vesicles, and release in response to physiological stimuli are highly regulated and mediated by three distinct G protein coupled receptors. Other receptors may bind or cross-bind vasopressin. Vasopressin is regulated spatially and temporally through transcriptional and post-transcriptional mechanisms, sex, tissue, and cell-specific receptor expression. Anomalies of vasopressin signaling have been observed in polycystic kidney disease, chronic heart failure, and neuropsychiatric conditions. Growing knowledge of the central biological roles of vasopressin has enabled pharmacological advances to treat these conditions by targeting defective systemic or central pathways utilizing specific agonists and antagonists.

The ratio standard is not adequate for scaling handgrip strength in judo athletes and nonathletes.

This study aimed to analyze if the ratio standard or the allometry is the best scaling methods of handgrip strength (HGS) for body mass (BM) in judo athletes and nonathletes, and to verify if the HGS mean values are higher in judo athletes than nonathletes when the BM effect is removed. One hundred forty-two individuals, being 88 judo athletes and 54 non-athletes participated in this study. The maximal isometric HGS was measured in judo athletes and nonathletes in the preferred hand. Only the allometry method was able to remove the BM effect of HGS. The al-lometric exponents found for athletes was b=0.68 and b=0.563 for non-athletes. A common allometric exponent was identified as (b=0.64) for comparing judo athletes and nonathletes. However, neither was able to allow for the comparison between groups due to a distortion of (bias; P<0.01). Thus, an index (HGSINDEX) was proposed to allow within-group (judo athletes and nonathletes) and between-group (judo athletes vs. nonathletes) comparison, removing the effect of BM. In summary, the allometric exponent based on the theory of geometric similarity (b=0.67) was able to remove the BM effect of HGS in judo athletes. An index (HGSINDEX) is suggested for classification (or rank) of the judoka in relation to the expected average of HGS.

Female Judo Athletes' Physical Test Performances Are Unrelated to Technical-Tactical Competition Skills.

This study analyzed the relationship between generic and judo-specific physical test performances and technical-tactical competition performances among 19 female judo athletes. Participant data were gathered in two stages: (a) physical tests-countermovement jump (CMJ), handgrip strength, Special Judo Fitness Test and Judogi Grip Strength Test; and (b) match performances recorded for technical-tactical analysis. Pearson's linear correlation and multiple linear regression analysis showed no significant correlations between any technical-tactical parameter and judo-specific physical tests. However, the number of attacks during matches was significantly positively correlated with countermovement jump height (CMJJH; r = 0.69, p = .002), peak power output (CMJPPO; r = 0.53, p = .002), and peak velocity (CMJPV; r = 0.62, p = .001). Effective time during matches was significantly correlated with all CMJ parameters (except maximum force; r = 0.65-0.76, p ≤ .01) and with right hand grip strength ( r = 0.48, p = .037). Match effectiveness was correlated with CMJPPO ( r = -0.67, p = .001), mean power output (CMJMPO; r = -0.54, p = .017), and CMJPV ( r = -0.54, p = .004). The explained power of variance was low for all variables at 45-54%. We conclude that judo-specific performance tests do not seem to be related to female judo athletes' technical-tactical skills in official competition, though athletes with higher lower limb muscle power and higher handgrip strength showed higher time effectiveness during matches.

Effect of official judo matches on handgrip strength and perceptual responses.

This study aimed to verify the effect of judo matches on handgrip strength and perceptual responses during an official tournament in medalists and nonmedalists. Thirty-four male judo athletes participated in an official judo tournament. Before the first match and immediately after each match, maximum isometric handgrip strength and rate of perceived exertion overall and in specific areas were assessed. Analysis of variance for repeated measures was used to compare variables before the first match and after each match, and t-test was used to compare medalists and nonmedalists with the level of significance set at 5%. Also, effect size (ES) analysis was used. The results showed decrease in handgrip strength in both hands from the third match (P<0.05). The rate of perceived exertion (RPE) increased from the first match and remained high over the subsequent matches (P<0.001). A very large effect for nonmedalist group (ES=3.44) and large effect for medalist group (ES=1.94) was found in the third match compared to prematch. Forearm and fingers were the body regions most cited by athletes in both groups. We concluded that an official judo competition induced significant drop in handgrip strength from the third match and increased the RPE from first match. Medalists seem to have better recovery after the third match compared to nonmedalists.

Effect of jumping interval training on neuromuscular and physiological parameters: a randomized controlled study.

This study analyzed the effect of 4 weeks of jumping interval training (JIT), included in endurance training, on neuromuscular and physiological parameters. Eighteen recreational runners, randomized in control and experimental groups, performed 40 min of running at 70% of velocity at peak oxygen uptake, for 3 times per week. Additionally, the experimental group performed the JIT twice per week, which consisted of 4 to 6 bouts of continuous vertical jumps (30 s) with 5-min intervals. Three days before and after the training period, the countermovement (CMJ) and continuous jump (CJ30), isokinetic and isometric evaluation of knee extensors/flexors, progressive maximal exercise, and submaximal constant-load exercise were performed. The JIT provoked improvement in neuromuscular performance, indicated by (i) increased jump height (4.7%; effect size (ES) = 0.99) and power output (≈ 3.7%; ES ≈ 0.82) of CMJ and rate of torque development of knee extensors in isometric contraction (29.5%; ES = 1.02); (ii) anaerobic power and capacity, represented by the mean of jump height (7.4%; ES = 0.8), and peak power output (PPO) (5.6%; ES = 0.73) of the first jumps of CJ30 and the mean of jump height (10.2%, ES = 1.04) and PPO (9.5%, ES = 1.1), considering all jumps of CJ30; and (iii) aerobic power and capacity, represented by peak oxygen uptake (9.1%, ES = 1.28), velocity at peak oxygen uptake (2.7%, ES = 1.11), and velocity corresponding to the onset of blood lactate accumulation (9.7%, ES = 1.23). These results suggest that the JIT included in traditional endurance training induces moderate to large effects on neuromuscular and physiological parameters.

Effect of different knee starting angles on intersegmental coordination and performance in vertical jumps.

This study aimed to analyze the effect of different knee starting angles on jump performance, kinetic parameters, and intersegmental coupling coordination during a squat jump (SJ) and a countermovement jump (CMJ). Twenty male volleyball and basketball players volunteered to participate in this study. The CMJ was performed with knee flexion at the end of the countermovement phase smaller than 90° (CMJ(<90)), greater than 90° (CMJ(>90)), and in a preferred position (CMJ(PREF)), while the SJ was performed from a knee angle of 70° (SJ(70)), 90° (SJ(90)), 110° (SJ(110)), and in a preferred position (SJ(PREF)). The best jump performance was observed in jumps that started from a higher squat depth (CMJ(<90)-SJ(70)) and in the preferred positions (CMJ and SJ), while peak power was observed in the SJ(110) and CMJ(>90). Analysis of continuous relative phase showed that thigh-trunk coupling was more in-phase in the jumps (CMJ and SJ) performed with a higher squat depth, while the leg-thigh coupling was more in-phase in the CMJ(>90) and SJ(PREF). Jumping from a position with knees more flexed seems to be the best strategy to achieve the best performance. Intersegmental coordination and jump performance (CMJ and SJ) were affected by different knee starting angles.

Reliability and validity of the 30-s continuous jump test for anaerobic fitness evaluation.

OBJECTIVES: To determine the test-retest reliability and concurrent validity of the 30-s continuous jump (CJ30) test using the Wingate test as a reference. DESIGN: Descriptive validity study. METHODS: Twenty-one male volleyball players (23.8 ± 3.8 years; 82.5 ± 9.1 kg; 185 ± 4.7 cm) were tested in three separate sessions. The first and second sessions were used to assess the reliability of the CJ30 while in the third session the Wingate test was performed. In the continuous jump test, consisting of maximal continuous jumps performed for 30s, jump height was determined by video kinematic analysis. Blood samples were collected after each test to determine lactate concentration. RESULTS: The CJ30 showed excellent test-retest reliability for the maximal jump height (ICC = 0.94), mean vertical jump height (ICC = 0.98) and fatigue index (ICC = 0.87). Peak lactate showed moderate reliability (ICC = 0.45). Large correlations were found between the mean height of the first four jumps of CJ30 and the peak power of the Wingate (r = 0.57), between the mean vertical jump height of CJ30 and the mean power of the Wingate (r = 0.70) and between the lactate peak of CJ30 and Wingate (r = 0.51). A moderate correlation of fatigue index between CJ30 and the Wingate was found (r = 0.43). CONCLUSIONS: The continuous jump is a reliable test and measures some of the same anaerobic properties as WAnT. The correlations observed in terms of anaerobic indices between the tests provide evidence that the CJ30 may adequately assess anaerobic performance level.

Nuevo test incremental para patinadores velocistas sobre una superficie plana deslizante: análisis de fiabilidad y comparación con un test de ciclismo / A novel incremental slide board test for speed skaters: Reliability analysis and comparison with a cycling test

Introducción: No parece ser adecuada la prescripción de ejercicio a patinadores a partir de los índices obtenidos en la bicicleta estática o la cinta rodante. Sin embargo, todavía no se ha establecido una valoración específica de laboratorio para patinadores. Objetivo: El objectivo de este estudio fue valorar la fiabilidad del test-retest de un test incremental ejecutado sobre una superficie plana deslizante (SB, del inglés slide board) y se comparó su validez, con un protocolo de ciclismo, para determinar el rendimiento aeróbico de los patinadores velocistas. Métodos: Diez patinadores de velocidad en línea de alto nivel ejecutaron 2 tests incrementales, uno en una SB y otro de ciclismo. La intensidad del test sobre SB fue determinada mediante cadencia, empezando por 30 impulsos/min y aumentando en 3 impulsos/min cada minuto hasta el agotamiento. Se midieron los valores máximo y submáximo relacionados con el umbral anaeróbico (AT), el consumo de oxígeno (VO2), la ventilación pulmonar (VE), la tasa de intercambio respiratorio (RER), la frecuencia cardíaca (FC), la escala de percepción del esfuerzo (RPE), la cadencia (CAD) y la concentración de lactato sanguíneo ([Lac]max).Resultados: No se encontraron diferencias significativas entre test y retest en la SB en ninguna de las variables. Se obtuvieron elevados niveles de fiabilidad relativa y absoluta (ICC > 0,9) (error típico de medida CVTEM < 3,5%) del VO2max, FCmax, [Lac]max, CADmax, VO2AT, CADAT y RPEAT. En comparación con el test de SB, el [Lac]max fue significativamente más alto durante el test de ciclismo y la RPTAT fue más baja. En VO2max, FCmax, CADmax, VO2AT y CADAT tuvieron una correlación alta entre el test de ciclismo y el SB (r > 0,8).Conclusión: Los resultados sugieren que el test de SB es fiable y adecuado para evaluar los índices de rendimiento aeróbico de patinadores velocistas

Introduction: Exercise prescription from indices obtained from cycling or running treadmill incremental tests does not seem suitable for speed skaters. However, the specificity of laboratory skating assessments remains to be established. Purpose: This study intended to assess the test-retest reliability of an incremental test performed on a slide board (SB), and its validity compared with a cycling protocol in order to determine aerobic performance indices in speed skaters. Methods: Ten competitive inline speed skaters performed two incremental tests on an SB and one cycling incremental test. The intensity of SB test was determined by cadence, starting at 30 push-offs/min and increasing by three push-offs/min each minute, until volitional exhaustion. Maximal and submaximal values related to the anaerobic threshold (AT) of oxygen uptake (VO2 ), pulmonary ventilation (VE), respiratory exchange (RER), heart rate (HR), rating of perceived effort (RPE), cadence (CAD), and blood lactate concentration ([Lac]max) were measured. Results: No significant differences were found in any of the variables between testretest on SB. High relative (ICC > 0.9) and absolute reliability (typical error of measure as CVTEM < 3.5%) were found for VO2max, HRmax, [Lac]max, CADmax, VO2AT, CADAT and RPEAT. In comparison to SB test, the [Lac]max was significantly higher during cycling, and the RPEAT was lower. VO2max, HRmax, CADmax, VO2AT and CADAT were largely correlated between cycling and SB (r > 0.8). Conclusions: The findings suggest that SB test is reliable and adequate to evaluate aerobic performance indices of speed skaters