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1.
J Sports Sci ; 42(8): 737-750, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38836573

RESUMO

The aims of the present study were to: i) analyse the between-session reliability of dry-land and in-water swimming tests, and ii) investigate the prevalence of meaningful asymmetries in swimming athletes. Twenty-eight swimmers (21 males, 7 females) performed anthropometric, shoulder range of motion (ROM), countermovement jump, shoulder isokinetic torque, and 15-s tethered swimming tests two times, 1 week apart. Inter-limb asymmetries were calculated for each variable. Raw data reliability was determined using the intraclass coefficient correlation (ICC) and the typical error of measurement (TEM), and effect size (ES) was used to determine systematic bias between test sessions. At an individual level, inter-limb asymmetries were compared to the coefficient of variation (CV) to determine whether they were real. The between-session reliability was good to excellent (0.75 to 1.00) for most of the raw data, except for ROM. Between-session ES was predominately "trivial" or "small" for raw data and asymmetries, reinforcing that the values did not change significantly between the sessions. In addition, real asymmetries were seen in some tested metrics, depending on the test. In conclusion, the tested variables presented good levels of between-session reliability and were able to detect real and consistent asymmetries.


Assuntos
Teste de Esforço , Amplitude de Movimento Articular , Natação , Humanos , Natação/fisiologia , Masculino , Reprodutibilidade dos Testes , Feminino , Adolescente , Amplitude de Movimento Articular/fisiologia , Teste de Esforço/métodos , Adulto Jovem , Torque , Antropometria , Ombro/fisiologia
2.
J Strength Cond Res ; 32(3): 708-715, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29466272

RESUMO

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.


Assuntos
Atletas , Teste de Esforço , Extremidade Inferior/fisiologia , Força Muscular/fisiologia , Esportes/fisiologia , Adulto , Humanos , Masculino , Adulto Jovem
3.
J Sports Sci ; 35(1): 81-88, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26949984

RESUMO

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.


Assuntos
Desempenho Atlético/fisiologia , Extremidade Inferior , Fadiga Muscular , Músculo Esquelético/fisiologia , Corrida/fisiologia , Futebol/fisiologia , Adolescente , Análise de Variância , Fenômenos Biomecânicos , Fadiga , , Humanos , Perna (Membro) , Amplitude de Movimento Articular , Coxa da Perna
4.
J Strength Cond Res ; 30(3): 818-24, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26332774

RESUMO

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.


Assuntos
Atletas/classificação , Desempenho Atlético , Peso Corporal , Exercício Físico , Adolescente , Adulto , Ergometria , Teste de Esforço , Humanos , Masculino , Conceitos Matemáticos , Adulto Jovem
5.
J Strength Cond Res ; 30(10): 2857-63, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26849787

RESUMO

do Nascimento Salvador, PC, Dal Pupo, J, De Lucas, RD, de Aguiar, RA, Arins, FB, and Guglielmo, LGA. The V[Combining Dot Above]O2 kinetics of maximal and supramaximal running exercises in sprinters and middle-distance runners. J Strength Cond Res 30(10): 2857-2863, 2016-The aim of this study was to compare the V[Combining Dot Above]O2 kinetics parameters during maximal and supramaximal running exercises in sprinters (SPR) and middle-distance runners (MDR). Twelve SPR (age 20.6 ± 3.4 years; and body mass 74.9 ± 6.2 kg) and 10 MDR (age 17.6 ± 1.4 years; and body mass 70.1 ± 11.8 kg) performed, on different days, a maximal incremental running test for determination of the velocity at maximum oxygen uptake (vV[Combining Dot Above]O2max) and 2 constant-speed tests for analysis of V[Combining Dot Above]O2 kinetics at 100 and 120% of vV[Combining Dot Above]O2max. The MDR presented significantly higher values for the critical speed (18.0 ± 1.0 vs. 14.2 ± 1.0 km·h), vV[Combining Dot Above]O2max (19.4 ± 0.7 vs. 17.2 ± 0.8 km·h), and time to exhaustion at 100% (437 ± 53 vs. 366 ± 49 seconds) than the SPR (p ≤ 0.05). However, the SPR demonstrated greater values for the anaerobic distance capacity (281.3 ± 66.1 vs. 208.0 ± 43.4 m). Although the mean response time and the time to attain the V[Combining Dot Above]O2max of the V[Combining Dot Above]O2 kinetics was higher in the maximal than supramaximal running speed (p ≤ 0.05), no difference was found in these parameters as well for V[Combining Dot Above]O2 slow component (p > 0.05) between the groups. This study showed that different aerobic and anaerobic characteristics in MDR and SPR did not affect the V[Combining Dot Above]O2 kinetics in maximal and supramaximal intensities within the severe-intensity domain. From a practical perspective, parameters of V[Combining Dot Above]O2 response may provide helpful information for training control as the duration of stimulus close to V[Combining Dot Above]O2max.


Assuntos
Teste de Esforço/métodos , Consumo de Oxigênio/fisiologia , Corrida/fisiologia , Adolescente , Adulto , Atletas , Estudos Transversais , Exercício Físico/fisiologia , Humanos , Cinética , Masculino , Oxigênio/metabolismo , Adulto Jovem
6.
J Strength Cond Res ; 29(4): 1010-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25426512

RESUMO

This study aimed to investigate the acute effects of simulated judo matches on fatigue and muscle damage markers. Twenty male judo athletes participated in this study. The athletes performed three 5-minute judo matches separated by 15 minutes of passive rest between each match. The following measurements were performed before and after each match: shoulder external/internal rotation isokinetic torque and countermovement jump (CMJ). Blood samples were taken before the first match and after the third match for serum creatine kinase (CK) and lactate dehydrogenase (LDH) analysis. T-tests for dependent samples and analysis of variance for repeated measures were used to compare the variables over the time; the level of significance was set at 0.05. An overall effect of the successive matches on shoulder internal (PTIN) and external (PTEX) rotation peak torque and CMJ performance was observed. PTIN and PTEX showed significant decreases in postmatch 2 and postmatch 3 when compared with the baseline (p < 0.01). Also, CMJ height declined in postmatch 2 and postmatch 3 (p < 0.01) when compared with the baseline. Serum CK and LDH activity increased significantly after the third match (p < 0.01). It was concluded that 3 successive judo matches induced a decline of peak torque and muscle power in the upper and lower limbs, respectively, and also provoked an increase of muscle damage markers. These findings may provide important knowledge for coaches and physical trainers to improve judo-specific strength training in both the upper and lower limbs.


Assuntos
Creatina Quinase/sangue , L-Lactato Desidrogenase/sangue , Artes Marciais/fisiologia , Fadiga Muscular/fisiologia , Adolescente , Adulto , Biomarcadores/sangue , Humanos , Masculino , Movimento/fisiologia , Músculo Esquelético/patologia , Rotação , Torque , Adulto Jovem
7.
Sports Biomech ; 13(4): 332-40, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25420210

RESUMO

The objective of this study was to investigate the effects of a simulated futsal match protocol on isokinetic knee torque production. Twenty-one young futsal players participated in this study and performed a futsal-specific protocol comprising two blocks of 20-minute activities to simulate the match demands. At pre-protocol, half-time, and post-protocol, the concentric and eccentric isokinetic peak torque of the knee flexor and extensor muscles, the angle of peak torque, and the conventional and functional torque ratios were assessed. ANOVA was used to compare the variables (significance level p <  0.05). A decrease of knee flexor and extensor eccentric torque and knee flexor concentric torque was found, in which the pre-protocol levels were higher than those at half-time, with both being larger than those at post-protocol. The knee extensor concentric torque reduced at half-time. The angle of eccentric torque of knee flexors increased, and the conventional and functional torque ratios decreased at post-protocol. In conclusion, the protocol produced a time-dependent reduction of knee flexor and extensor torque in both concentric and eccentric actions. These findings suggested a possible impairment of performance and the emergence of risk factors for hamstring strains during a futsal match.


Assuntos
Fadiga/fisiopatologia , Articulação do Joelho/fisiopatologia , Músculo Esquelético/fisiopatologia , Futebol/fisiologia , Adolescente , Humanos , Masculino , Força Muscular/fisiologia , Corrida/fisiologia , Torque , Adulto Jovem
8.
J Sports Med Phys Fitness ; 64(5): 432-438, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38411044

RESUMO

BACKGROUND: The goal of this study was to verify whether anthropometric, physiological and neuromuscular factors, as well as training characteristics, could predict cycling performance during maximal incremental and time-to-exhaustion tests. METHODS: Twenty cyclists were evaluated: Anthropometric variables, knee extensor muscle activation and architecture, training history, and training volume were assessed. Second ventilatory threshold (VT2), maximal oxygen uptake (VO2MAX), and maximal power output (POMAX) were assessed during the incremental test. Muscle architecture of the vastus lateralis (VL) and rectus femoris (RF) muscles was evaluated bilaterally to calculate the mean thighs' muscle thickness, pennation angle and fascicle length, at rest condition. After that, time-to-exhaustion test at POMAX was performed. Muscle activation of the VL, RF and vastus medialis (VM) was evaluated of both legs. RESULTS: Cyclists' height (r2=0.37), experience time and training volume (r2=0.46) were predictors of POMAX (P<0.02), while cadence (r2=0.30) was the only predictive variable for the time-to-exhaustion performance (P<0.01). CONCLUSIONS: These results suggest that training characteristics and experience are important when training for incremental cycling conditions, whereas cadence (and its determinant variables) should be looked at during maximal and exhaustive conditions.


Assuntos
Desempenho Atlético , Ciclismo , Consumo de Oxigênio , Humanos , Ciclismo/fisiologia , Masculino , Adulto , Desempenho Atlético/fisiologia , Consumo de Oxigênio/fisiologia , Teste de Esforço , Músculo Esquelético/fisiologia , Antropometria , Músculo Quadríceps/fisiologia , Adulto Jovem
9.
Sports Biomech ; 12(3): 259-71, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24245051

RESUMO

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.


Assuntos
Desempenho Atlético/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Movimento/fisiologia , Adulto , Humanos , Masculino , Destreza Motora , Análise e Desempenho de Tarefas , Adulto Jovem
10.
Res Sports Med ; 21(2): 124-35, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23541099

RESUMO

The purpose of the study was to analyze the relationships among physiological and neuromuscular indices with the 200- and 400-m sprint running performance. Fourteen male sprinters performed the following tests: determination of 200- (P200) and 400-m (P400) running performance; determination of VO2max and the velocity associated at VO2max; squat jump (SJ) and countermovement jump (CMJ); and maximal accumulated oxygen deficit (MAOD). Significant correlations were observed between SJ (r = -0.53), CMJ (r = -0.69), and MAOD (r = -0.65) with P200. Countermovement jump (CMJ) and MAOD explained 70% of the P200. The MAOD was the only variable to correlate significantly with P400 (r = -0.56); VO2max and CMJ were also selected in the regression together and explained 79% of P400. The indicators of muscular power and anaerobic capacity are capable of explaining P200. In the 400 m, the performance was determined by indices of anaerobic capacity, in conjunction with the athletes' aerobic and muscular power.


Assuntos
Limiar Anaeróbio , Desempenho Atlético/fisiologia , Músculo Esquelético/fisiologia , Corrida/fisiologia , Adolescente , Adulto , Teste de Esforço , Tolerância ao Exercício , Humanos , Ácido Láctico/sangue , Masculino , Movimento/fisiologia , Força Muscular , Consumo de Oxigênio , Adulto Jovem
11.
Sports Med Open ; 9(1): 4, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36625965

RESUMO

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.

12.
Eur J Sport Sci ; 22(6): 857-866, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33840359

RESUMO

Purpose: The objective of this study was to evaluate a plyometric conditioning activity (3 sets of 5 countermovement jumps, [CA]) for twitch properties and voluntary knee extension. Methods: After a familiarization session, fourteen highly trained sprint athletes, 12 men (23.25 ± 7.17 years) and 2 women (23.0 ± 2.8 years) performed 2 experiments, each in a randomized order (crossover design). In one experiment, the time-course of twitch contractile properties was evaluated with and without the previous CA at 2, min intervals to 10 min of recovery. In the second session, maximal voluntary knee extension was evaluated at the same recovery intervals, for control and experimental condition in random order. Results: Mixed-model ANOVA with Bonferroni post-hoc revealed significant differences between pre-test and 2 min (p < 0.01, ES = 0.42) and 4 min (p < 0.01, ES = 0.20) for peak twitch torque of quadriceps femoris muscles confirming postactivation potentiation [PAP] at these times. Twitch rate of torque development (RTD) was significantly greater than pre-test value only at 2 min (p < 0.01, ES = 0.58) after the CA. Twitch contraction time and ½ relaxation time were not significantly difference from pre-test values after the CA (p > 0.05). No significant difference was observed for voluntary RTD following CA. Conclusion: The plyometric CA increased twitch peak torque and RTD consistent with PAP; however, there was no effect of CA on voluntary RTD of knee extension at any time after the plyometric CA. Even with PAP confirmed, we observed that the CA fails to improve isometric RTD of quadriceps femoris muscles. HighlightsA plyometric CA significantly increased twitch peak torque (at 2 and 4 min) and twitch rate of torque development (at 2 min) of quadriceps femoris muscles, indicating postactivation potentiation (PAP).No effect was observed for twitch contraction time and ½ relaxation time after the CA.No improvement was observed on voluntary rate of torque development evaluated at the same time intervals.


Assuntos
Exercício Pliométrico , Atletas , Estudos Cross-Over , Eletromiografia , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Torque
13.
J Strength Cond Res ; 25(7): 2034-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21701288

RESUMO

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.


Assuntos
Desempenho Atlético/fisiologia , Teste de Esforço/métodos , Movimento/fisiologia , Análise e Desempenho de Tarefas , Adulto , Fenômenos Biomecânicos , Teste de Esforço/instrumentação , Feminino , Humanos , Masculino , Análise de Regressão , Reprodutibilidade dos Testes , Adulto Jovem
14.
Int J Sports Physiol Perform ; 16(4): 565-572, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33440339

RESUMO

PURPOSE: The objective of this study was to analyze the effects of a conditioning activity (CA) composed of continuous countermovement jumps on twitch torque production and 30-m sprint times. METHODS: A total of 12 sprint athletes, 10 men (23.5 [7.7] y) and 2 women (23.0 [2.8] y), volunteered to participate in this study. The participants were evaluated in 2 sessions as follows: (1) to determine the effects of the CA (3 sets of 5 continuous vertical jumps with a 1-min interval between sets) on 30-m sprint performance over time (2, 4, 6, 8, and 10 min) and (2) to evaluate twitch peak torque to determine the magnitude and time course of the induced postactivation potentiation at the same recovery intervals. RESULTS: Mixed-model analysis of variance with Bonferroni post hoc verified that there was a decrease on the 30-m sprint time at 2 minutes (P = .01; Δ = 2.78%; effect size [ES] = 0.43) and 4 minutes (P = .02; Δ = 2%, ES = 0.30) compared with pre when the CA preceded the sprints. The peak torque of quadriceps also showed significant increase from pretest to 2 minutes (P < .01; Δ = 17.0% [12.2%]; ES = 0.45) and 4 minutes (P = .02; Δ = 7.2% [8.8%]; ES = 0.20). CONCLUSION: The inclusion of CA composed of continuous countermovement jumps in the warm-up routine improved 30-m sprint performance at 2- and 4-minute time intervals after the CA (postactivation performance enhancement). Since postactivation potentiation was confirmed with electrical stimulation at the time when sprint performance increased, it was concluded that postactivation potentiation may have contributed to the observed performance increases.


Assuntos
Desempenho Atlético , Corrida , Exercício de Aquecimento , Atletas , Feminino , Humanos , Masculino , Torque
15.
Appl Physiol Nutr Metab ; 45(4): 349-356, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31557447

RESUMO

The transient increase in torque of an electrically evoked twitch following a voluntary contraction is called postactivation potentiation (PAP). Phosphorylation of myosin regulatory light chains is the most accepted mechanism explaining the enhanced electrically evoked twitch torque. While many authors attribute voluntary postactivation performance enhancement (PAPE) to the positive effects of PAP, few actually confirmed that contraction was indeed potentiated using electrical stimulation (twitch response) at the time that PAPE was measured. Thus, this review aims to investigate if increases in voluntary performance after a conditioning contraction (CC) are related to the PAP phenomenon. For this, studies that confirmed the presence of PAP through an evoked response after a voluntary CC and concurrently evaluated PAPE were reviewed. Some studies reported increases in PAPE when PAP reaches extremely high values. However, PAPE has also been reported when PAP was not present, and unchanged/diminished performance has been identified when PAP was present. This range of observations demonstrates that mechanisms of PAPE are different from mechanisms of PAP. These mechanisms of PAPE still need to be understood and those studying PAPE should not assume that regulatory light chain phosphorylation is the mechanism for such enhanced voluntary performance. Novelty The occurrence of PAP does not necessarily mean that the voluntary performance will be improved. Improvement in voluntary performance is sometimes observed when the PAP level reaches extremely high values. Other mechanisms may be more relevant than that for PAP in the manifestation of acute increases in performance following a conditioning contraction.


Assuntos
Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Desempenho Atlético/fisiologia , Estimulação Elétrica , Exercício Físico , Humanos
16.
J Exerc Rehabil ; 16(2): 175-182, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32509703

RESUMO

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.

17.
Sports Biomech ; 17(4): 502, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29370715

RESUMO

The aim of this study was to investigate the effect of cadence on volume load (VLoad) and muscle activity during agonist -antagonist paired sets (APS) in the lower body. Twelve trained men (24.0 ± 3.3 years; 78.3 ± 9.7 kg; 1.77 ± 0.58 m) volunteered to participate in this study. After the 10 maximum repetition test for leg extension and seated leg curl, participants performed three experimental protocols: first protocol (traditional)-three sets of only leg extension (60 bpm); second protocol (fast cadence)-three sets of leg extension, with each set preceded by one set on the seated leg curl with fast cadence (90 bpm); third protocol (slow cadence)-similar to the second, but seated leg curl with slow cadence (40 bpm). The total number of repetitions, VLoad and the electromyography activity for the vastus lateralis, vastus medialis and rectus femoris muscles were recorded. The VLoad was higher during APS than the traditional method, but the cadence (fast or slow) of antagonist exercise did not influence VLoad. Muscle activity of vastus lateralis was higher during traditional protocol; on the other hand, rectus femoris showed higher activity on APS fast cadence protocol, indicating that APS has a different influence on quadriceps components.


Assuntos
Perna (Membro)/fisiologia , Músculo Quadríceps/fisiologia , Treinamento Resistido/métodos , Adulto , Fenômenos Biomecânicos , Eletromiografia , Humanos , Masculino , Fadiga Muscular/fisiologia , Treinamento Resistido/instrumentação , Adulto Jovem
18.
Percept Mot Skills ; 125(4): 802-816, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29788859

RESUMO

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.


Assuntos
Atletas , Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Força da Mão/fisiologia , Artes Marciais/fisiologia , Adolescente , Teste de Esforço , Feminino , Humanos , Força Muscular/fisiologia , Adulto Jovem
19.
J Bodyw Mov Ther ; 22(3): 798-804, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30100315

RESUMO

This study aimed to analyze the effects of Mat Pilates on isokinetic torque of the lower limbs in elderly women. Fourteen elderly women (Age 62 ± 3 yr) participated in 12 weeks of Mat Pilates training (60-min sessions, 3 times per week). Repetitions increased every 4 weeks and the difficulty of exercises progressed from beginner to intermediate and advanced. Peak torque was assessed before (week -4 and week 0, considered as a control period) and after 6 and 12 weeks of a periodized Mat Pilates intervention. The results showed significant improvements (p < 0.05) in concentric and eccentric peak torque of knee flexors muscles, hip flexor and extensor muscles after 12 weeks. Mechanical work showed significant improvement (p < 0.05) for knee extensor muscles during eccentric contractions after week 12, for hip extensor muscles during concentric contractions week 12, and for flexor muscles during concentric and eccentric contractions after week 12. We conclude that the periodization of Mat Pilates induced significant improvements in multiple isokinetic torque parameters.


Assuntos
Técnicas de Exercício e de Movimento/métodos , Articulação do Joelho/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Torque , Idoso , Fenômenos Biomecânicos , Feminino , Humanos , Pessoa de Meia-Idade , Amplitude de Movimento Articular/fisiologia , Saúde da Mulher
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