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1.
Pediatr Exerc Sci ; : 1-8, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796177

RESUMO

PURPOSE: The aim of this study was to explore the interday reliability of mechanical variables obtained from the horizontal and vertical force-velocity (FV) profiles in adolescent female basketball players. If found to be reliable, the associations between FV parameters (theoretical maximal force, velocity, and power), squat jump (SJ) height, 30-m sprint, and change of direction (COD) times were evaluated. METHODS: After familiarization, SJ against incremental loads, 30-m sprint, and 505-COD tests were obtained twice in 36 adolescent female basketball players (age = 15.4 [1.2] y). RESULTS: Reliability for vertical FV parameters was unacceptable, whereas 505-COD times and FV horizontal parameters (except for theoretical maximal power) showed a moderate to high reliability. 505-COD time was correlated with FV horizontal parameters (range: r = -.821, -.451), and a large association was observed with both SJ height (r = -.678, -.600) and 30-m sprint time (r = .813, .858). CONCLUSIONS: Due to low levels of strength, our athletes were not adequately prepared to obtain a reliable vertical FV profile. Practitioners can expect acceptable reliability of the horizontal FV profile. Given the association between COD performance and SJ height and 30-m sprint time, we encouraged practitioners with limited equipment at their disposal to use COD and/or 30-m sprint tests.

2.
J Musculoskelet Neuronal Interact ; 23(1): 43-51, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36856099

RESUMO

OBJECTIVES: The main aim of this study was to determine the effects of set configuration during five weeks of unilateral knee extension resistance training on untrained knee extensors performance. METHODS: Thirty-five subjects were randomly assigned to traditional training (TTG; n=14), rest-redistribution (RRG; n=10) and control group (CON; n=11). TTG and RRG groups trained the dominant knee extensors twice a week with the 10-repetition maximum (RM) load. TTG performed four sets of eight repetitions with three min-rest between sets and RRG 32 repetitions with 17.4 seconds of rest between each one. Before and after interventions, anthropometry, muscle thickness (MT), pennation angle (PA), 1RM, number of repetitions with 10RM pretest load (N10RM), maximum propulsive power (MPP) and maximum voluntary isometric contraction (MVIC) were measured. RESULTS: 1RM of the untrained leg increased only in the TTG group (p<0.001, 10.3% compared with Pre-test). 1RM, MPP and N10RM increased in the trained leg in both TTG (p<0.001) and RRG (p<0.001). No changes occurred in MT or PA. CONCLUSIONS: These results suggest that, when it is not possible to perform bilateral exercises (e.g., leg injury), traditional set configurations should be recommended to improve maximal voluntary force in the untrained leg.


Assuntos
Terapia por Exercício , Treinamento Resistido , Humanos , Exercício Físico , Articulação do Joelho , Antropometria
3.
Scand J Med Sci Sports ; 33(8): 1360-1372, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36920047

RESUMO

The aim of the present cross-sectional study was to determine if chronic rock climbing and climbing-specific resistance training (RT) would modify the reticulospinal tract (RST) efficacy. Sixteen healthy, elite level climbers (CL; n = 16, 5 F; 29.8 ± 6.7 years) with 12 ± 7 years of climbing and climbing-specific RT experience and 15 healthy recreationally active participants (CON; n = 15, 4 F; 24.6 ± 5.9 years), volunteered for the study. We quantified RST efficacy by comparing the effects of a startle stimulus over reaction time (Rtime ) and measured rate of force development (RFD) and surface electromyography (sEMG) in representative muscles during powerful hand grip contractions. Both groups performed two Rtime tasks while performing rapid, powerful gripping with the right hand (Task 1) or during 3-s-long maximal voluntary right hand grip contractions in response to an imperative visual signal alone (V), or combined with a auditory-non startle stimulus (A) or/and startling auditory stimulus (S). We also tested the reproducibility of these responses on two separate days in CON. Intersession reliability ranged from 0.34 to 0.96 for all variables. The CL versus CON was 37% stronger (p = 0.003). The S stimulus decreased Rtime and increased RFD and sEMG in both groups during both tasks (all p < 0.001). Rtime was similar between groups in all conditions. However, CL had a greater RFD from 50 to 100 ms compared with CON only after the S stimulus in both tasks (p < 0.05, d = 0.85-0.96). The data tentatively suggest that chronic rock climbing and climbing-specific RT might improve RST efficacy, by increasing RST input to the α-motoneurons.


Assuntos
Força da Mão , Montanhismo , Humanos , Reprodutibilidade dos Testes , Força da Mão/fisiologia , Músculo Esquelético/fisiologia , Dedos/fisiologia , Estudos Transversais , Montanhismo/fisiologia
4.
J Strength Cond Res ; 35(9): 2414-2420, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31136543

RESUMO

ABSTRACT: Fariñas, J, Mayo, X, Giraldez-García, MA, Carballeira, E, Fernandez-Del-Olmo, M, Rial-Vazquez, J, Kingsley, JD, and Iglesias-Soler, E. Set configuration in strength training programs modulates the cross education phenomenon. J Strength Cond Res 35(9): 2414-2420, 2021-This study aimed to compare the strength gains in the nontrained arm after 2 independent unilateral training programs differing in the set configuration. Thirty-five subjects were randomly assigned to 3 groups: traditional training (TT; n = 12), cluster training (CT; n = 11), or control (CON; n = 12). The experimental groups performed a 5-week training program of a unilateral biceps curl exercise with the dominant limb using the 10 repetition maximum (10RM) load. Traditional training performed 5 sets of 6 repetitions and 135 seconds of rest between sets. Cluster training completed 30 repetitions with 18.5 seconds of rest between each repetition. Anthropometry (ANT), muscle thickness (MT), 1RM, the number of repetitions with 10RM (n10RM), and isometric maximal voluntary contraction (MVC) were measured before and after the intervention. Regarding the nontrained arm, TT improved 1RM (7.3%, p < 0.001). No changes were observed in CT. Regarding the trained arm, TT improved 1RM (9.1%, p < 0.001), n10RM (p = 0.005), and MVC (p = 0.011), whereas CT only showed a trend for improvement of 1RM (3.4%, p = 0.052). These results suggest that when total volume and repetition-to-rest ratio are equated, a more fatiguing set configuration causes a higher effect on the non-trained limb.


Assuntos
Treinamento Resistido , Humanos , Contração Isométrica , Força Muscular , Músculo Esquelético , Descanso
5.
Eur J Appl Physiol ; 120(8): 1881-1891, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32533243

RESUMO

PURPOSE: This study aimed to explore the acute effect of transcranial direct current stimulation (tDCS) on the force-velocity relationship, strength training volume, movement velocity, and ratings of perceived exertion. METHODS: Fourteen healthy men (age 22.8 ± 3.0 years) were randomly stimulated over the dorsolateral prefrontal cortex with either ANODAL, CATHODAL or SHAM tDCS for 15 min at 2 mA. The one-repetition maximum (1RM) and force-velocity relationship parameters were evaluated during the bench press exercise before and after receiving the tDCS. Subsequently, participants completed a resistance training session consisting of sets of five repetitions with 1 min of inter-set rest against the 75%1RM until failure. RESULTS: No significant changes were observed in the 1RM or in the force-velocity relationship parameters (p ≥ 0.377). The number of repetitions was higher for the ANODAL compared to the CATHODAL (p = 0.025; ES = 0.37) and SHAM (p = 0.009; ES = 0.47) conditions. The reductions of movement velocity across sets were lower for the ANODAL than for the CATHODAL and SHAM condition (p = 0.014). RPE values were lower for the ANODAL compared to the CATHODAL (p = 0.119; ES = 0.33) and SHAM (p = 0.150; ES = 0.44) conditions. No significant differences between the CATHODAL and SHAM conditions were observed for any variable. CONCLUSION: The application of ANODAL tDCS before a resistance training session increased training volume, enabled the maintenance of higher movement velocities, and reduced RPE values. These results suggest that tDCS could be an effective method to enhance resistance-training performance.


Assuntos
Tolerância ao Exercício , Treinamento Resistido/métodos , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Humanos , Masculino , Movimento , Contração Muscular , Córtex Pré-Frontal/fisiologia
6.
J Sports Sci ; 36(1): 111-115, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28125330

RESUMO

This study analysed the effects of bilateral and non-dominant practice on novice practitioners' lateral preference for judo skills in a combat context (i.e., randori). Thirty sports sciences students (22 men and 8 women; mean age 19 ± 1 years) with right hand, foot, and counterclockwise rotation preferences were divided into 3 groups: bilateral (BG; n = 8), non-dominant (NDG; n = 11), and control (CG; n = 11). Participants received 8 weeks of training at a rate of 3 days per week. The NDG was trained to perform judo skills exclusive with their non-dominant side, while the BG performed every task symmetrically. Before and after training, participants were recorded during two 3-min randoris to obtain the percentage of their engagement in dominant side actions. Pretest percentages were 73.1 ± 19.9%, 77.8 ± 18.8%, and 68.9 ± 27.2% for BG, NDG, and CG, respectively. Post-test values were 75.0 ± 15.6%, 23.3 ± 27.9%, and 72.2.9 ± 20.4%, respectively. Significant differences were observed between NDG and each of the other groups after the training. Changes from pretest were only significant for NDG (P = 0.003). These results suggest that lateral preference among novice judo practitioners during randori can be modulated by the type of practice.


Assuntos
Desempenho Atlético/fisiologia , Lateralidade Funcional/fisiologia , Artes Marciais/fisiologia , Destreza Motora/fisiologia , Condicionamento Físico Humano/métodos , Feminino , Humanos , Masculino , Adulto Jovem
7.
Muscle Nerve ; 56(1): 152-159, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28346689

RESUMO

INTRODUCTION: The aim of this study was to investigate the effects of high intensity resistance circuit (HIRC) and traditional strength training (TST) on neuromuscular fatigue and metabolic responses. METHODS: Twelve trained young subjects performed HIRC and TST in a counterbalanced order with 1 week rest in-between. The amount of workload and the inter-set time for each local muscle group were matched (180 s), however, the time between successive exercises differed. The twitch interpolation technique was used to test neuromuscular function of the knee extensor muscles. Blood lactate concentration was used to evaluate metabolic responses. RESULTS: Maximum voluntary contraction and resting potentiated twitch amplitude (Qtw ) were significantly reduced after HIRC, but there were not changes after TST, while reductions in voluntary activation were similar. Lactate concentration increased significantly more after HIRC. CONCLUSIONS: The higher lactate concentration after HIRC probably impaired excitation-contraction coupling, indicating larger peripheral fatigue than after TST. Muscle Nerve 56: 152-159, 2017.


Assuntos
Ataxia Cerebelar/reabilitação , Exercícios em Circuitos/métodos , Fadiga Muscular/fisiologia , Estudos de Casos e Controles , Ataxia Cerebelar/complicações , Ataxia Cerebelar/diagnóstico por imagem , Feminino , Humanos , Ácido Láctico/metabolismo , Masculino , Nervo Mediano/diagnóstico por imagem , Nervo Ulnar/diagnóstico por imagem , Doenças Vestibulares/complicações , Doenças Vestibulares/diagnóstico por imagem , Doenças Vestibulares/reabilitação
8.
J Appl Biomech ; 33(2): 144-152, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27918682

RESUMO

The main aim of this study was to analyze the effect of resistance training programs differing in set configuration on mechanical force-velocity profiles. Thirteen participants performed 10 unilateral knee extension training sessions over 5 weeks. Each limb was randomized to one of the following set configurations: traditional (4 sets of 8 repetitions at maximum intended velocity, 10RM load, 3-min pause between sets) or interrepetition rest (32 maximum intended velocity repetitions, 10RM load, 17.4 s of rest between each repetition). Velocity of each repetition was recorded throughout the program. Before and after training, individual linear force velocities were calculated, and the following parameters were obtained: force and velocity axis intercept, slope, and estimated maximum power. Mean velocity was higher throughout the program for interrepetition rest configuration (0.54 ± 0.01 vs. 0.48 ± 0.01 m∙s-1 for interrepetition rest, and traditional configuration respectively; main effect of set configuration: P < .001). There was a significant increase in force and velocity intercepts, but a steeper negative slope after both training protocols (main effect of time: P < .001 for every variable). Differences in resistance training velocity did not affect the adaptations. Our results suggest that, in a short-term program, maximum intended rather than actual velocity is a key factor to modulate strength adaptations.


Assuntos
Adaptação Fisiológica/fisiologia , Movimento/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Aptidão Física/fisiologia , Treinamento Resistido/métodos , Feminino , Humanos , Articulação do Joelho/fisiologia , Masculino , Adulto Jovem
9.
J Sports Sci ; 34(15): 1473-84, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26630355

RESUMO

This study compared the functional and neural effects of two strength training programmes differing in set configuration. Thirteen participants performed 10 sessions, over a period of 5 weeks, of unilateral leg extensions with different set configurations but with identical work-to-rest ratios for each limb: a traditional configuration (4 sets of 8 repetitions, 10RM load, 3-min pause between sets) and an inter-repetition rest configuration (32 repetitions, 10RM load, 17.4 s of rest between each repetition). Mean propulsive velocity of the traditional sessions was lower than for inter-repetition rest sessions (0.48 ± 0.06 vs. 0.54 ± 0.06 m · s(-1); P < 0.001), while perceived exertion was higher (8.3 ± 0.9 and 6.56 ± 1.6 for traditional training and IRT; P = 0.002). One repetition maximum (RM), work with 10RM load, maximum mean propulsive power, maximum voluntary contraction and time to failure with 50% of maximum isometric force improved similarly in both legs (time effect, P < 0.001; effect size range, 0.451-1.190). Time and set configuration did not show significant main effects or interactions for cortical adaptations (motor-evoked potentials, short-interval intracortical inhibition, intracortical facilitation). There were no significant correlations between changes in cortical and peripheral neural adaptations and strength improvement. In conclusion, inter-repetition rest configuration was as effective as traditional training in improving muscle performance.


Assuntos
Adaptação Fisiológica , Força Muscular/fisiologia , Treinamento Resistido/métodos , Antropometria , Potencial Evocado Motor , Feminino , Humanos , Contração Isométrica , Masculino , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Percepção , Esforço Físico , Recrutamento Neurofisiológico , Descanso , Adulto Jovem
10.
J Strength Cond Res ; 30(9): 2565-73, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26817741

RESUMO

Mayo, X, Iglesias-Soler, E, Fariñas-Rodríguez, J, Fernández-del-Olmo, M, and Kingsley, JD. Exercise type affects cardiac vagal autonomic recovery after a resistance training session. J Strength Cond Res 30(9): 2565-2573, 2016-Resistance training sessions involving different exercises and set configurations may affect the acute cardiovascular recovery pattern. We explored the interaction between exercise type and set configuration on the postexercise cardiovagal withdrawal measured by heart rate variability and their hypotensive effect. Thirteen healthy participants (10 repetitions maximum [RM] bench press: 56 ± 10 kg; parallel squat: 91 ± 13 kg) performed 6 sessions corresponding to 2 exercises (Bench press vs. Parallel squat), 2 set configurations (Failure session vs. Interrepetition rest session), and a Control session of each exercise. Load (10RM), volume (5 sets), and rest (720 seconds) were equated between exercises and set configurations. Parallel squat produced higher reductions in cardiovagal recovery vs. Bench press (p = 0.001). These differences were dependent on the set configuration, with lower values in Parallel squat vs. Bench press for Interrepetition rest session (1.816 ± 0.711 vs. 2.399 ± 0.739 Ln HF/IRR × 10, p = 0.002), but not for Failure session (1.647 ± 0.904 vs. 1.808 ± 0.703 Ln HF/IRR × 10, p > 0.05). Set configuration affected the cardiovagal recovery, with lower values in Failure session in comparison with Interrepetition rest (p = 0.027) and Control session (p = 0.022). Postexercise hypotension was not dependent on the exercise type (p > 0.05) but was dependent on the set configuration, with lower values of systolic (p = 0.004) and diastolic (p = 0.011) blood pressure after the Failure session but not after an Interrepetition rest session in comparison with the Control session (p > 0.05). These results suggest that the exercise type and an Interrepetition rest design could blunt the decrease of cardiac vagal activity after exercise while exercising to muscular failure may contribute to the onset of postexercise hypotension.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Coração/fisiologia , Treinamento Resistido/métodos , Adolescente , Adulto , Pressão Sanguínea , Exercício Físico/fisiologia , Frequência Cardíaca , Humanos , Hipotensão/etiologia , Masculino , Hipotensão Pós-Exercício , Treinamento Resistido/efeitos adversos , Descanso/fisiologia , Nervo Vago/fisiologia , Levantamento de Peso/fisiologia , Adulto Jovem
11.
Eur J Appl Physiol ; 115(8): 1605-25, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26037127

RESUMO

PURPOSE: We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. METHODS: Systematic literature review and meta-analysis. RESULTS: Whole body vibration combined with exercise had an overall 0.3 % acute effect on maximal voluntary leg force (-6.4 %, effect size = -0.43, 1 study), leg power (4.7 %, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 %, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 %, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 % chronic effect on maximal voluntary leg force (14.6 %, weighted mean effect size = 0.44, 5 studies), leg power (10.7 %, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 %, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 %, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). CONCLUSIONS: Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance.


Assuntos
Desempenho Atlético/fisiologia , Vibração , Humanos , Educação Física e Treinamento
12.
Percept Mot Skills ; 119(3): 825-37, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25456248

RESUMO

Set configuration refers to the repetitions performed with regard to the maximum possible number of repetitions, a factor affecting RPE that has not been previously studied. This study analyzed the effect of set configuration and muscle mass on RPE. Eight students (M age = 23.7 yr. ± 1.7) completed four sessions corresponding to types of exercise with different amount of muscle mass (bench press and parallel squat) and two set configurations: a session with five sets of repetitions to failure and a cluster session. The cluster session involved the same intensity, volume, and rest than the failure session, guaranteeing the same work-to-rest ratio. RPE was higher in Failure vs Cluster sessions and higher in parallel squat vs bench press. This suggests that set configuration influences RPE. Similarly, RPE can be affected by the muscle mass of the exercise performed.


Assuntos
Percepção/fisiologia , Esforço Físico/fisiologia , Treinamento Resistido/métodos , Descanso/psicologia , Levantamento de Peso/psicologia , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Treinamento Resistido/estatística & dados numéricos , Descanso/fisiologia , Levantamento de Peso/fisiologia , Levantamento de Peso/estatística & dados numéricos , Adulto Jovem
13.
Brain Cogn ; 82(3): 243-53, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23721994

RESUMO

Functional connectivity was evaluated in patients with schizophrenia (SC) and in patients with Parkinson's disease (PD) during the performance of a local contextual processing paradigm, to investigate the proposition that functional disconnection is involved with contextual processing deficits in these populations. To this end, we utilized event-related EEG signals, synchronization likelihood and graph theoretical analysis. Local context was defined as the occurrence of a predictive sequence of stimuli before the presentation of a target event. In the SC patients, we observed a decrease in path length (L) in the beta band, for the predictive sequence and for predicted and random targets, compared with controls. These abnormalities were associated with weaker frontal-temporal-parietal connections. In the PD patients we found longer L (theta band) for predicted targets, and higher cluster coefficients for both the predictive sequence (theta band) and predicted targets (alpha and theta bands), compared with controls. Detection of predicted targets was associated with weaker frontal-parietal connections in PD. No group differences were found for randomized standard stimuli in both SC and PD patients. These findings provide evidence of task-specific functional connectivity abnormalities within frontal networks during local contextual processing.


Assuntos
Encéfalo/fisiopatologia , Doença de Parkinson/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Encéfalo/patologia , Ondas Encefálicas , Sincronização Cortical , Feminino , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade , Doença de Parkinson/patologia , Esquizofrenia/patologia
14.
Exp Gerontol ; 178: 112220, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37230335

RESUMO

Treadmill walking is considered a useful therapeutic tool for improving gait in Parkinson's disease (PD) patients. The study investigated the role of top-down, frontal-parietal versus bottom-up parietal-frontal networks, during over-ground and treadmill walking in PD and control subjects, using functional connectivity. To this end, EEG was recorded simultaneously, during a ten-minute period of continuous walking either over-ground or on a treadmill, in thirteen PD patients and thirteen age-matched controls. We evaluated EEG directed connectivity, using phase transfer entropy in three frequency bands: theta, alpha and beta. PD patients showed increased top-down connectivity during over-ground compared with treadmill walking, in the beta frequency range. Control subjects showed no significant differences in connectivity between the two walking conditions. Our results suggest that in PD patients, OG walking was associated with increased allocation of attentional resources, compared with that on the TL. These functional connectivity modulations may shed further light on the mechanisms underlying treadmill versus overground walking in PD.


Assuntos
Doença de Parkinson , Humanos , Caminhada , Marcha , Teste de Esforço
15.
Artigo em Inglês | MEDLINE | ID: mdl-37107746

RESUMO

The objective of this pilot study was to evaluate the effects of dual-task training implemented by mobile health technology on performance on motor and dual-task tests in subjects with dementia. Nineteen subjects with a medical diagnosis of dementia were assigned to an experimental group (EG, n = 12) or control group (CG, n = 7). The EG participated in 24 sessions (3/week) of a homebase dual-task exercises program, in addition to their ongoing cognitive and physiotherapy treatment. The training program was implemented individually in the patient's home by caregivers or relatives through electronic devices controlled by a mobile application. Before (Pre) and after (Post) the program, performance on motor and motor/cognitive (dual-task) tests were evaluated. Motor evaluation included gait at preferred and maximal speed, the Up and Go, and the Handgrip Strength test. Dual-task tests included gait with subtraction 3 s from 100 and naming animals (verbal fluency). The CG only performed the evaluations in addition to their cognitive and physiotherapy treatment. The statistical analysis (ANOVA Group*Test) showed a statically significant improvement for both dual-task tests in the EG after the training program, while the CG showed an impairment in the verbal fluency test. Conclusion: the implementation of a home exercise program carried out with mobile technology in people with dementia is feasible and positively affects their performance on dual tasks.


Assuntos
Demência , Força da Mão , Humanos , Projetos Piloto , Marcha , Terapia por Exercício , Demência/terapia
16.
Mov Disord ; 27(12): 1570-3, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23032947

RESUMO

BACKGROUND: Auditory external cues enhance step initiation in Parkinson's disease (PD) patients. We wanted to explore whether a startle reaction has a comparable effect on step initiation in PD. METHODS: Thirteen PD patients and 13 aged-matched controls participated in this study. Electromyography pattern and onset toe-off time during a step initiation task were recorded in response to three different stimuli: a visual imperative stimulus; visual stimulus simultaneous with a nonstartle auditory stimulus and with a startle auditory stimulus. RESULTS: In all subjects, onset of tibialis anterior was faster in the startle auditory condition, compared with the nonstartle auditory condition. However, in the patient group, there was no difference in onset of soleus and toe-off between the startle and nonstartle conditions. CONCLUSIONS: Startle reaction in PD patients demonstrates a disordered coupling between the anticipatory postural adjustments that initiate the weight shift and the movement to initiate toe-off during step initiation.


Assuntos
Doença de Parkinson/fisiopatologia , Reflexo de Sobressalto/fisiologia , Estimulação Acústica , Adulto , Idoso , Análise de Variância , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação/fisiologia
17.
Exp Brain Res ; 219(1): 27-36, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22430185

RESUMO

We investigated the effect of abstract versus real-life meaningful images from sports on local contextual processing in two groups of professional athletes. Local context was defined as the occurrence of a short predictive series of stimuli occurring before delivery of a target event. EEG was recorded in 10 professional basketball players and 9 professional athletes of individual sports during three sessions. In each session, a different set of visual stimuli were presented: triangles facing left, up, right, or down; four images of a basketball player throwing a ball; four images of a baseball player pitching a baseball. Stimuli consisted of 15 % targets and 85 % of equal numbers of three types of standards. Recording blocks consisted of targets preceded by randomized sequences of standards and by sequences including a predictive sequence signaling the occurrence of a subsequent target event. Subjects pressed a button in response to targets. In all three sessions, reaction times and peak P3b latencies were shorter for predicted targets compared with random targets, the last most informative stimulus of the predictive sequence induced a robust P3b, and N2 amplitude was larger for random targets compared with predicted targets. P3b and N2 peak amplitudes were larger in the professional basketball group in comparison with professional athletes of individual sports, across the three sessions. The findings of this study suggest that local contextual information is processed similarly for abstract and for meaningful images and that professional basketball players seem to allocate more attentional resources in the processing of these visual stimuli.


Assuntos
Basquetebol/psicologia , Potenciais Evocados Visuais/fisiologia , Imaginação , Campos Visuais/fisiologia , Percepção Visual/fisiologia , Adulto , Análise de Variância , Eletroencefalografia , Humanos , Masculino , Estimulação Luminosa , Valor Preditivo dos Testes , Tempo de Reação , Adulto Jovem
18.
Exp Brain Res ; 223(1): 43-50, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22941316

RESUMO

Brain-derived neurotrophic factor (BDNF) plays an important role in learning, memory, and brain plasticity. Humans with a val66met polymorphism in the BDNF gene have reduced levels of BDNF and alterations in motor learning and short-term cortical plasticity. In the current study, we sought to further explore the role of BDNF in motor learning by testing human subjects on a visuomotor adaptation task. In experiment 1, 21 subjects with the polymorphism (val/met) and 21 matched controls (val/val) were tested during learning, short-term retention (45 min), long-term retention (24 h), and de-adaptation of a 60° visuomotor deviation. We measured both mean error as well as rate of adaptation during each session. There was no difference in mean error between groups; however, val/met subjects had a reduced rate of adaptation during learning as well as during long-term retention, but not short-term retention or de-adaptation. In experiment 2, 12 val/met and 12 val/val subjects were tested on a larger 80° deviation, revealing a more pronounced difference in mean error during adaptation than the 60° deviation. These results suggest that BDNF may play an important role in visuomotor adaptive processes in the human.


Assuntos
Adaptação Fisiológica/fisiologia , Fator Neurotrófico Derivado do Encéfalo/genética , Aprendizagem/fisiologia , Polimorfismo Genético/genética , Substituição de Aminoácidos , Análise de Variância , Interpretação Estatística de Dados , Feminino , Genótipo , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Adulto Jovem
19.
Neurosci Lett ; 782: 136691, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35605902

RESUMO

Anodal transcranial direct current stimulation (tDCS) can enhance the retention of a previously practiced motor skill. However, the effects of tDCS on the performance of the choice reaction time task are not fully understood. We examined the effects of anodal tDCS over the left primary motor cortex (M1) on the retention of a 4-choice visual-motor reaction time task (4-ChRT). Right-handed healthy participants (n = 100) were randomly assigned to five groups: three groups received anodal tDCS: before (tDCSbefore), during (tDCSduring), or after (tDCSafter) motor practice. In addition, there were two control groups: with (CONmp) and without (CON) motor practice. We evaluated the speed and precision of the 4-ChRT task before (PRE), during, and 24 h (POST) after the interventions. All groups, including the non-stimulation (CONmp) and non-practice groups (CON), improved (p < 0.05) motor retention (Δ4-ChRT: 35.8 ± 36.0 ms). These findings suggest that the tDCS effects over M1 may differ for serial versus choice RT tasks, perhaps due to the different brain areas involved in each motor task.


Assuntos
Córtex Motor , Estimulação Transcraniana por Corrente Contínua , Humanos , Aprendizagem/fisiologia , Córtex Motor/fisiologia , Destreza Motora/fisiologia , Tempo de Reação/fisiologia
20.
PeerJ ; 10: e14035, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36217384

RESUMO

Background: Maximal aerobic speed (MAS) is a useful parameter to assess aerobic capacity and estimate training intensity in middle- and long-distance runners. However, whether middle- and long-distance runners reach different levels of MAS compared to other endurance athletes with similar V̇O2max has not been previously studied. Therefore, we aimed to compare V̇O2max, MAS and spatiotemporal parameters between sub-elite middle- and long-distance runners (n = 6) and endurance non-runners (n = 6). In addition, we aimed to compare the maximal blood lactate concentration [BLa] experienced by participants after conducting these tests. Methods: Telemetric portable respiratory gas analysis, contact and flight time, and stride length and rate were measured using a 5-m contact platform during an incremental test at a synthetic athletics track. V̇O2, heart rate, respiratory quotient values in any 15 s average period during the test were measured. [BLa] was analyzed after the test . Running spatiotemporal parameters were recorded at the last two steps of each 400 m lap. A coefficient of variation (%CV) was calculated for each spatiotemporal variable in each participant from 8 km h-1 onwards. Results: Whereas runners reported faster MAS (21.0 vs. 18.2 km h-1) than non-runners (p  =  0.0001, ES = 3.0), no differences were found for V̇O2max and maximum blood lactate concentration during the running tests (p > 0.05). While significant increases in flight time and stride length and frequency (p < 0.001, 0.52 ≤ η p 2 ≤ 0.8) were observed throughout the tests, decreases in contact time (p < 0.001, η p 2 = 0 . 9 ) were reported. Runners displayed a greater %CV (p = 0.015) in stride length than non-runners. We conclude that middle- and long-distance runners can achieve a faster MAS compared to non-running endurance athletes despite exhibiting a similar V̇O2max. This superior performance may be associated to a greater mechanical efficiency. Overall, runners displayed a greater ability to modify stride length to achieve fast speeds, which may be related to a more mechanically efficient pattern of spatiotemporal parameters than non-runners.


Assuntos
Consumo de Oxigênio , Resistência Física , Humanos , Resistência Física/fisiologia , Consumo de Oxigênio/fisiologia , Testes de Função Respiratória , Atletas , Lactatos
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