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1.
Adv Physiol Educ ; 48(3): 512-517, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38721651

RESUMO

Internationalization in higher education is essential, and although active learning methodologies are increasing and allow students to develop transversal skills, most still have a very local scope. In this context, the Collaborative Online International Learning (COIL) methodology is an interesting approach to benefit the students' development. It consists of an online program that involves creating multicultural teams to develop a specific learning project. Although this methodology is expanding, its use in physiology is still scarce. This paper aims to show an example of applying COIL methodology in physiology topics to enhance higher-education students' innovation and business skills. Our example project developed a sports-assessment service concept focused on physiology and biomechanics assessments. The program involved teams from Brazil, Germany, and Spain, comprising undergraduate and master students. Over 7 weeks, these teams, mentored by professors and researchers, engaged in workshops covering COIL methodology, business model design, executive summary planning, economic analyses, and communication techniques. Key outcomes included learning new concepts, developing soft skills, building confidence in innovative solution proposals, and experiencing diverse cultures. Challenges faced were language barriers, scheduling, task complexity, and logistical issues. This experience confirms the effectiveness of incorporating programs using COIL methodology into educational curriculums. Doing so exposes physiology students to innovation, entrepreneurship, and business creation while strengthening their professional connections and opening up postgraduation opportunities.NEW & NOTEWORTHY Although the Collaborative Online International Learning (COIL) methodology is expanding, its use in physiology is still scarce. Our example COIL project of 7 weeks developed a sports-assessment service concept focused on physiology and biomechanics assessments. The program involved teams from Brazil, Germany, and Spain, comprising undergraduate and master's students. Students perceived extracurricular activities in this format as beneficial. Coaches also expressed positive views about such initiatives, noting benefits for students and their development.


Assuntos
Fisiologia , Humanos , Fisiologia/educação , Educação a Distância/métodos , Internacionalidade , Currículo , Comportamento Cooperativo
2.
J Therm Biol ; 123: 103923, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39067196

RESUMO

Skin temperature responses have been advocated to indicate exercise-induced muscle soreness and recovery status. While the evidence is contradictory, we hypothesize that the presence of muscle damage and the time window of measurement are confounding factors in the skin temperature response. The objective was to determine whether skin temperature is influenced by different workloads and the time course of temperature measurements over the following 24 h. 24 trained male military were assigned to one of three groups: GC group (n = 8) serving as control not performing exercises, GE group (n = 8) performing a simulated military combat protocol in an exercise track with different obstacles but designed not to elicit muscle damage, and the GEMD group (n = 8) performing the simulated military combat protocol plus 5 sets of 20 drop jumps, with 10-sec between repetitions and with 2-min of rest between sets aiming to induce muscle damage. Skin temperature was measured using infrared thermography before exercise (Pre) and 4 (Post4h), 8 (Post8h) and 24h (Post24h) post-exercise. Perception of pain (DOMS) was evaluated Pre, Post24h, and Post48h, and countermovement jump height was evaluated at Pre and Post24h. DOMS did not differ between groups in the Pre and Post24h measures but GEMD presented higher DOMS than the other groups at Post48h (p < 0.001 and large effect size). Jump height did not differ for GEMD and GC, and GE presented higher jump height at Post24h than GC (p = 0.02 and large effect size). Skin temperature responses of GEMD and GG were similar in all measurement moments (p > 0.22), and GE presented higher skin temperature than the GC and the GEMD groups at Post24h (p < 0.01 and large effect sizes). In conclusion, although physical exercise elicits higher skin temperature that lasts up to 24 h following the efforts, muscle soreness depresses this response.

3.
J Sports Sci ; 41(6): 526-535, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37379499

RESUMO

The aim of the present study was to determine whether fatigue affects internal and external load variables determining power profile in cyclists. Ten cyclists performed outdoor power profile tests (lasting 1-, 5 and 20-min) on two consecutive days, subject either to a fatigued condition or not. Fatigue was induced by undertaking an effort (10-min at 95% of average power output obtained in a 20-min effort followed by 1-min maximum effort) until the power output decreased by 20% compared to the 1-min power output. Fatigued condition decreased power output (p < 0.05, 1-min: 9.0 ± 3.8%; 5-min: 5.9 ± 2.5%; 20-min: 4.1 ± 1.9%) and cadence in all test durations, without differences in torque. Lactate decreased in longer efforts when a fatigue protocol had previously been conducted (e.g., 20-min: 8.6 ± 3.0 vs. 10.9 ± 2.7, p < 0.05). Regression models (r2 ≥ 0.95, p < 0.001) indicated that a lower variation in load variables of 20-min in fatigued condition compared with the non-fatigued state resulted in a lower decrease in critical power after the fatigue protocol. The results suggest that fatigued condition on power was more evident in shorter efforts and seemed to rely more on a decrease in cadence than on torque.


Assuntos
Fadiga , Ácido Láctico , Humanos , Tempo , Ciclismo , Consumo de Oxigênio , Teste de Esforço
4.
J Therm Biol ; 115: 103612, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37379651

RESUMO

Muscle fatigue can limit performance both in sports and daily life activities. Consecutive days of exercise without a proper recovery time may elicit cumulative fatigue. Although it has been speculated that skin temperature could serve as an indirect indicator of exercise-induced adaptations, it is unclear if skin temperature measured by infrared thermography (IRT) could be an outcome related to the effects of cumulative fatigue. In this study, we recruited 21 untrained women and induced cumulative fatigue in biceps brachii over two consecutive days of exercise. We measured delayed onset muscle soreness (DOMS, using a numeric rate scale), maximal strength (using a dynamometer), and skin temperature (using IRT) in exercise and non-exercise muscles. Cumulative fatigue reduced muscle strength and increased DOMS. Skin temperature in the arm submitted to cumulative fatigue was higher for minimum and mean temperature, being asymmetrical in relation to the control arm. We also observed that the variations in the minimum and mean temperatures correlated with the strength losses. In summary, skin temperature measured by IRT seems promising to help detect cumulative fatigue in untrained women, being useful to explain strength losses. Future studies should provide additional evidence for the potential applications not only in trained participants but also in patients that may not be able to report outcomes of scales or precisely report DOMS.


Assuntos
Músculo Esquelético , Termografia , Humanos , Feminino , Músculo Esquelético/fisiologia , Mialgia/diagnóstico , Fadiga Muscular/fisiologia , Exercício Físico/fisiologia
5.
J Sport Rehabil ; 32(1): 40-45, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35961646

RESUMO

CONTEXT: Comfort and pain in cyclists are often discussed as a result of the posture on the bike, and bike fit, including motion analysis, is advocated as a strategy to minimize these conditions. The relationship between cycling kinematics, comfort, and pain is still debatable. OBJECTIVES: To investigate the association of ankle, knee, and trunk kinematics with the occurrence of anterior knee pain (AKP) in mountain bike cyclists. DESIGN: Cross-sectional study. METHODS: Fifty cross-country mountain bike cyclists (26 with AKP and 24 without AKP) had their pedaling kinematics assessed. Linear and angular data from trunk, hip, knee, ankle, and foot from cyclists with and without AKP were recorded using Retül motion analysis system. RESULTS: The binary logistic regression model showed that kinematic variables such as peak ankle plantar flexion, peak knee flexion, and forward trunk lean were significant predictors of AKP. Both larger peak plantar flexion and knee flexion decreased the probability of reporting AKP. On the other hand, larger forward trunk lean increased the probability of reporting AKP. CONCLUSIONS: Ankle, knee, and trunk sagittal kinematics may predict AKP in cross-country mountain bike cyclists, whereas hip, knee, and ankle alignment in the frontal plane showed no association with occurrence of AKP. In other words, cyclists with larger ankle plantar flexion and knee flexion are less likely to have AKP, whereas those with increased trunk forward lean are more likely to have AKP.


Assuntos
Ciclismo , Joelho , Humanos , Fenômenos Biomecânicos , Estudos Transversais , Articulação do Joelho , Dor
6.
Int J Sports Med ; 43(6): 545-552, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34729731

RESUMO

Physical and cognitive exercises have positive long-term effects on cognitive capacities. However, acute effects still are controversial. Here we determine the acute effects of physical exercise combined with concurrent cognitive exercise on cognitive performance in young adults. Simple reaction time, selective attention, and memory were evaluated in 23 young men before and after 30 min of stationary cycling exercise, 30 min of stationary cycling exercise combined with cognitive exercise, and 30 min of rest. Exercise intensity was continuously controlled to ensure exercise at moderate intensity. We found that physical exercise combined with cognitive dual-task improves selective attention. Both exercise conditions showed similar effects on simple reaction time, and memory was not affected by the different exercise conditions. We conclude that the combination of cycling exercise at moderate intensity with a cognitive exercise acutely improves selective attention in young adults. These results can be of particular interest for interventions aiming at improving selective attention in sports and for older adults and individuals with difficulty to suppress and filter out task-irrelevant information, like when receiving instruction or learning a new task or concept.


Assuntos
Atenção , Ciclismo , Idoso , Cognição , Exercício Físico/psicologia , Terapia por Exercício/métodos , Humanos , Masculino , Adulto Jovem
7.
J Therm Biol ; 110: 103345, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36462854

RESUMO

Infrared thermography (IRT) has become popular in several areas of knowledge. However, the analyses of thermal images often request manual actions, and little is known about the effect of the evaluator's experience on analysis thermal images. Here, we determine the reproducibility of IRT images analysis performed by evaluators with different levels of experience. Eight evaluators (GE, group experienced, n = 4; GN, group novice, n = 4) analyzed thermograms from 40 healthy participants recorded before and after exercise to determine the mean, minimum, maximum, standard deviation, and range of skin temperature in the anterior thigh and posterior leg. Before and after exercise, mean temperature showed excellent reproducibility for both groups for the anterior thigh (ICC >0.98) and posterior leg (ICC >0.94), and maximum temperature showed excellent reproducibility for both groups in the posterior leg (ICC >0.91). The influence of experience level was not significant considering the anterior thigh. Similarly, experience level did not affect the mean, maximum, and standard deviation temperature determined for the posterior leg. For the posterior leg, minimum temperature presented lower values and the range was higher among novice evaluators. Mean skin temperature showed narrower 95% limits of agreement than minimum and maximum for both regions and moments. Caution is advised when temperature ranges and minimums are determined by different evaluators. We conclude that for IRT analysis by evaluators with different levels of experience, the mean and maximum temperatures should be prioritized due to their better reproducibility.


Assuntos
Temperatura Cutânea , Termografia , Humanos , Reprodutibilidade dos Testes , Processamento de Imagem Assistida por Computador , Exercício Físico
8.
Foot Ankle Surg ; 28(1): 37-43, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33509663

RESUMO

BACKGROUND: Achilles' tendon ruptures result in impaired plantar flexion strength and endurance. It is interesting to know the plantar flexion strength, the number of heel-rise repetitions, and the maximal calf circumference following Achilles' tendon ruptures repair. METHODS: Both the injured and non-injured legs of thirty male patients with Achilles' tendon ruptures treated with the percutaneous Dresden technique were compared with the ankle function of 30 healthy participants. Rehabilitation involved partial weight-bearing for three weeks and then increased to full weight-bearing and ankle exercises. RESULTS: The injured legs had weaker plantar flexion strength (1.64 ± 0.17 Nm/kg) compared with the non-injured legs (1.91 ± 0.24 Nm/kg; p = 0.002) and the healthy participants' legs (1.93 ± 0.32 Nm/kg; p < 0.001). The non-injured leg had greater ability in doing heel-rise repetitions (39.4 ± 6.1 rep.) compared with the injured legs (37.2 ± 5.7 rep.; p < 0.023) and the healthy participants' legs (31.0 ± 13.0 rep.; p < 0.001). CONCLUSIONS: The injured leg had not recovered full isometric strength but had improved heel-rise repetition.


Assuntos
Tendão do Calcâneo , Traumatismos dos Tendões , Tendão do Calcâneo/cirurgia , Calcanhar/cirurgia , Humanos , Masculino , Ruptura/cirurgia , Traumatismos dos Tendões/cirurgia , Resultado do Tratamento
9.
Proc Natl Acad Sci U S A ; 115(10): E2403-E2409, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29463708

RESUMO

Recently, nongenetic animal models to study the onset and development of Alzheimer's disease (AD) have appeared, such as the intrahippocampal infusion of peptides present in Alzheimer amyloid plaques [i.e., amyloid-ß (Aß)]. Nonpharmacological approaches to AD treatment also have been advanced recently, which involve combinations of behavioral interventions whose specific effects are often difficult to determine. Here we isolate the neuroprotective effects of three of these interventions-environmental enrichment (EE), anaerobic physical exercise (AnPE), and social enrichment (SE)-on Aß-induced oxidative stress and on impairments in learning and memory induced by Aß. Wistar rats were submitted to 8 wk of EE, AnPE, or SE, followed by Aß infusion in the dorsal hippocampus. Short-term memory (STM) and long-term memory (LTM) of object recognition (OR) and social recognition (SR) were evaluated. Biochemical assays determined hippocampal oxidative status: reactive oxygen species, lipid peroxidation by thiobarbituric acid reactive substance (TBARS) test, and total antioxidant capacity by ferric reducing/antioxidant power (FRAP), as well as acetylcholinesterase activity. Aß infusion resulted in memory deficits and hippocampal oxidative damage. EE and AnPE prevented all memory deficits (STM and LTM of OR and SR) and lipid peroxidation (i.e., TBARS). SE prevented only the SR memory deficits and the decrease of total antioxidant capacity decrease (i.e., FRAP). Traditionally, findings obtained with EE protocols do not allow discrimination of the roles of the three individual factors involved. Here we demonstrate that EE and physical exercise have better neuroprotective effects than SE in memory deficits related to Aß neurotoxicity in the AD model tested.


Assuntos
Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/toxicidade , Terapia por Exercício , Transtornos da Memória/terapia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/metabolismo , Animais , Exercício Físico , Hipocampo/metabolismo , Humanos , Peroxidação de Lipídeos , Masculino , Aprendizagem em Labirinto , Memória , Transtornos da Memória/metabolismo , Transtornos da Memória/psicologia , Estresse Oxidativo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Meio Social
10.
Adv Physiol Educ ; 45(4): 715-719, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34498937

RESUMO

Remote teaching can be both challenging and motivating. Professors and lecturers have developed innovative strategies to improve students' education and engage students in synchronous and asynchronous classes. In this Illuminations paper, we describe BodyWorks, online tools to support courses in physiology, motor control, and biomechanics. The tools are interactive and easy to use, have low computer and internet demands, and can be used in many conditions and topics of study. All resources are freely available online in three different languages. We hope our initiative can help professors and students worldwide promote more interactive and engaging motor control and related topics classes for both synchronous and asynchronous formats.


Assuntos
Manipulações Musculoesqueléticas , Estudantes , Fenômenos Biomecânicos , Humanos , Internet , Ensino
11.
Adv Physiol Educ ; 45(1): 53-58, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33464193

RESUMO

Programming is an important skill for different areas of knowledge. While in the past, programming skills were much more related to fields of computer sciences and engineering, today, professionals from different areas benefit from the ability to write codes for different applications. Furthermore, programming stimulates logical thinking, which impacts other personal abilities. Health science students have limited exposure to programming during their studies. Aware of this and considering the prolonged time in social distancing in Brazil due to the SARS-COV2 pandemic in 2020, we organized an outreach course dedicated to teaching introductory concepts of programming for health science students. The activity was developed fully online using the Zoom web conference agent, lasting 12 wk (8 synchronous classes, 15 synchronous hours in total), and attended by 27 undergraduate and graduate students from two different universities. A collaborative problem-based learning and group-learning methodology were developed through asynchronous homework and mainly online synchronous activities. In this article, we describe our approach and provide some suggestions for replicating the course in other universities. We observed that the activities of the outreach course improved programming skills and confidence for most of the students. More importantly, it piqued their interest enough to motivate them to continue to practice writing and testing their programs. We concluded that an outreach course dedicated to programming promoted improvements in programming skills in health science students. Furthermore, the program was an opportunity to keep the students active in science while working from their homes during the pandemic.


Assuntos
Disciplinas das Ciências Biológicas/educação , COVID-19 , Educação a Distância , Informática/educação , Pandemias , SARS-CoV-2 , Software , Estudantes/psicologia , Comunicação por Videoconferência , Adulto , Brasil , Currículo , Feminino , Humanos , Masculino , Aprendizagem Baseada em Problemas , Interface Usuário-Computador , Adulto Jovem
12.
Adv Physiol Educ ; 45(1): 34-36, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33464189

RESUMO

The "Biomechanics without Borders: Teaching Biomechanics in Brazil and South Africa" involved academics from different countries combining efforts to improve remote education. In addition to the live discussions, the event resulted in the availability of online content to help academic staffs improve teaching strategies in the field of human movement sciences.


Assuntos
Ensino , Fenômenos Biomecânicos , Brasil , Humanos , África do Sul
13.
J Therm Biol ; 100: 103051, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34503798

RESUMO

Infrared thermography (IRT) has gained popularity in sports medicine for determining whether changes in skin temperature relate to pain and muscle damage. Such a relationship would support IRT as a non-invasive method to monitor these physiological responses. However, the literature remains controversial. Here, we determine the relationship between exercise-induced muscle soreness (DOMS), pain, and skin temperature in men and women before and after exercise. Twenty-two physically active adults (10 men and 12 women) completed a squat exercise protocol to induce muscle damage. Skin temperature, DOMS, and pressure pain threshold (PPT) were assessed in the quadriceps pre, post-exercise, and 48 h post-exercise. DOMS increased similarly in men and women post-exercise and 48 h post-exercise. PPT was lower in women compared to men. PPT decreased 48 h post-exercise for men but did not differ between the moments for women. Skin temperature responses were sex-dependent. Mean and maximum temperatures increased post-exercise for men, and maximum temperature reduced 48 h post-exercise. In women, the minimum temperature increased 48 h post-exercise. DOMS was not predicted by skin temperature but showed a direct association between pre and 48 h post-exercise variation of maximum skin temperature and PPT. We conclude that there is a sex-dependent effect in analyzing skin temperature changes in response to exercise, something that seems to not have been addressed in previous studies. To date, inferences are generally assumed as similar for both men and women, which we show may not be the case.


Assuntos
Exercício Físico/efeitos adversos , Mialgia/fisiopatologia , Limiar da Dor , Temperatura Cutânea , Adulto , Feminino , Humanos , Masculino , Fadiga Muscular , Mialgia/etiologia , Fatores Sexuais
14.
Int J Sports Med ; 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32599640

RESUMO

Intense exercise promotes long-term gains in cognitive functions. On the other hand, intense exercise may result in acute effects not clearly determined for cognitive performance. A condition of stochastic intensity ranging from moderate to maximal efforts is part of sports like cycling, in which cognitive integrity is also important for fast decision making and information processing especially during high-speed performances. In this study we investigate the acute effect of cycling at intensities corresponding to 60%, 80% and 95% of the maximal power output (MP) on selective attention, reaction time and short-term memory in amateur trained cyclists. In this cross sectional study 20 male cyclists performed maximal and submaximal cycling tests under different exercise intensities. Cognitive measures were conducted before and after exercise. We found that short duration high intensity cycling (95%) improves selective attention but increases variability in simple reaction time responses, without significant effects on short-term memory. The high intensity exercise improves ability to manage more complex cognitive task especially when the variability in the task does not increase.

15.
J Manipulative Physiol Ther ; 43(8): 816-823, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32893026

RESUMO

OBJECTIVE: The purpose of this study was to compare changes in thickness of the transverse abdominis during performance of the hollowing exercise guided by feedback using ultrasonography images together with verbal guidance and using verbal guidance alone. We also determined the minimal detectable change and agreement between normalized pressures and muscle thickness. METHODS: Twenty participants without lumbar pain performed the hollowing exercises with or without ultrasonography feedback: 7 men and 13 women, mean (SD) age = 25 (5) years, height = 166 (10) cm, body mass = 64 (6) kg, body mass index = 22.2 (5.8) kg/m2. The thickness of the transverse abdominis was quantified during the exercise using musculoskeletal ultrasonography. Basal and 3 repetitions guided by an evaluator were performed. Pressure was determined using a lumbar cushion. Data were compared with a mixed-model analysis of variance and Bonferroni post hoc test (P < .05). Minimal detectable changes were identified and Bland-Altman analysis performed considering normalized thickness and pressure. RESULTS: Ultrasonography feedback resulted in larger thickness changes (P < .05). The lowest minimal detectable changes were achieved using ultrasonography feedback. Nonagreement was found between normalized thickness and pressure. CONCLUSION: Contraction of the transverse abdominis is improved using real-time ultrasonography together with verbal feedback. Low changes in muscle contraction estimated by thickness showed nonagreement with a pressure cushion.


Assuntos
Músculos Abdominais/fisiologia , Exercício Físico/psicologia , Retroalimentação , Conhecimento Psicológico de Resultados , Contração Muscular/fisiologia , Ultrassonografia/métodos , Adulto , Índice de Massa Corporal , Terapia por Exercício/métodos , Feminino , Humanos , Masculino , Educação Física e Treinamento/métodos , Pressão , Adulto Jovem
16.
J Therm Biol ; 84: 431-438, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466783

RESUMO

There are controversial results in the literature concerning the concept that cumulative training load could affect basal skin temperature in the days following training sessions. The objective was to measure skin temperature in triathletes during a training camp with cumulative training load. Ten male recreational triathletes involved in a training camp underwent measurements of perception of pain and fatigue (visual analogue scale), skin temperature (infrared thermography), and jump performance (counter movement jump test) before, one day, and two days after the beginning of the training camp. All measurements were performed before the breakfast. Jump height did not differ between the days (p > 0.05). Fatigue perception increased after the first and second day of training for most of the body regions (p < 0.05). Pain perception increased after two days of training (p < 0.05). Mean and maximum skin temperature increased after the second day of training for most of the body regions (p < 0.05). Skin temperature in some body regions was directly related with muscle mass, weekly training volume, and inverse related with fatigue perception (p < 0.05 and R2 > 0.4). Possible explanations of these results in comparison with previous studies may include the influence of control of the intrinsic and extrinsic factors related to the skin temperature assessment (for instance, the time of the day, lack of muscle soreness, daily activity control). These preliminary results have important implication on the use of skin basal temperature data to monitor exercise recovery, which claims for further research.


Assuntos
Exercício Físico/fisiologia , Temperatura Cutânea , Adulto , Atletas , Ciclismo/fisiologia , Humanos , Pessoa de Meia-Idade , Fadiga Muscular , Mialgia , Resistência Física/fisiologia
17.
Biol Sport ; 36(3): 209-216, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31624414

RESUMO

This study examined the relationships between vertical jump asymmetries and speed and power performance in elite female soccer athletes. Sixteen professional female soccer players (age: 23.0 ± 3.8 years; body mass: 60.2 ± 7.3 kg; height: 165.1 ± 5.5 cm) from the same professional club participated in this study. Athletes performed unilateral and bilateral squat jumps (SJ) and countermovement jumps (CMJ) on a portable force plate; 30-m sprinting test; Zigzag change-of-direction (COD) test; and muscle power testing using the jump squat (JS) exercise. Asymmetry scores were obtained from the results of the unilateral SJ and CMJ by the percentage difference between the dominant and non-dominant legs. The Pearson product-moment coefficient of correlation was used to analyse the correlations between the bilateral and unilateral vertical jump variables and the physical tests. The bilateral vertical jump performance (in both SJ and CMJ) was closely related to sprinting and JS power performances (r values ranging from 0.50 to 0.73; P< 0.05). In contrast, no significant associations were found between jump asymmetries and performance measures. Our data suggest that asymmetry scores derived from unilateral vertical jumps are not capable of influencing the speed-power performance of professional female soccer players.

18.
Eur J Appl Physiol ; 118(9): 2021-2027, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29987354

RESUMO

PURPOSE: To determine the effects of performing a self-regulated cognitive dual task on time to failure and neuromuscular force control during submaximal isometric contractions. METHODS: Fifteen young sedentary males performed isometric contractions at 50% of each individual's maximal voluntary contraction (MVC) under single-task (without cognitive load) and dual-task (with self-regulated mathematical task) conditions. Force signal complexity and biceps brachialis muscle activity were determined at the start, middle, and end of each trial. The slope of the linear regression of median frequency determined the rate of muscle fatigue. Force-task error was established as any amplitude percentage greater or less than 50% MVC. RESULTS: The dual-task condition resulted in a 42 s longer time to failure than the single-task condition. EMG amplitude did not differ between conditions. The rate of muscle fatigue was higher in the single-task (- 0.35%/s) than the dual-task (- 0.2%/s) condition. Force signal complexity was, on average, 22% lower in the dual-task condition. The dual-task condition, as compared to the single-task condition, elicited a higher rate of force-task error below (6.37 versus 4.76%) and over (2.11 versus 1.68%) the force threshold. CONCLUSION: The dual-task condition resulted in a longer time to failure and decreased motor output complexity and fatigue rate when performing a submaximal force task. As the dual task also increased the force-task error, we suggest cognitive dual tasks as a possible strategy for delaying fatigue in sedentary young males when exerting submaximal isometric force, contributing to neuromuscular training when error in force control can be ignored.


Assuntos
Cognição/fisiologia , Contração Isométrica/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto , Cotovelo/fisiologia , Eletromiografia/métodos , Fadiga/fisiopatologia , Humanos , Masculino , Fadiga Muscular/fisiologia , Resistência Física/fisiologia , Esforço Físico/fisiologia , Torque , Adulto Jovem
19.
J Sports Sci ; 36(17): 2018-2024, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29369014

RESUMO

Sampling bias is an issue for research involving cyclists. The heterogeneity of cyclist populations, on the basis of skill level and riding purpose, can generate incorrect inferences about one specific segment of the population of interest. In addition, a more accurate categorization would be helpful when physiological parameters are not available. This study proposes using self-reported data to categorize amateur cyclist types by varying skill levels and riding purposes, therefore improving sample selection in experimental studies. A total of 986 cyclists completed an online questionnaire between February and October 2016. Two-step cluster analyses were performed to generate distinct groups, and dependent variables of these groups were compared (demographics and characteristics of cycling practice). The cluster analysis relied on 4 descriptors (cycling weekly volume, average cycling speed, riding purpose, and cycling discipline) and yielded five distinct groups: competitive road, recreational road, competitive mountain bike (MTB), recreational MTB and competitive triathlon. Among these groups, averages and distributions for age, height, body mass, body mass index, training volume and intensity, and years of experience varied. This categorization can potentially help researchers recruit specific groups of cyclists based upon self-reported data and therefore better align the sample characteristic with the research aims.


Assuntos
Ciclismo/classificação , Sujeitos da Pesquisa , Antropometria , Análise por Conglomerados , Humanos , Destreza Motora , Projetos de Pesquisa , Estudos Retrospectivos , Viés de Seleção , Autorrelato , Inquéritos e Questionários
20.
J Sports Sci ; 36(11): 1305-1311, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28869740

RESUMO

Walking is one of the preferred exercises among elderly, but could a prolonged walking increase gait variability, a risk factor for a fall in the elderly? Here we determine whether 30 min of treadmill walking increases coefficient of variation of gait in elderly. Because gait responses to exercise depend on fitness level, we included 15 sedentary and 15 active elderly. Sedentary participants preferred a lower gait speed and made smaller steps than the actives. Step length coefficient of variation decreased ~16.9% by the end of the exercise in both the groups. Stride length coefficient of variation decreased ~9% after 10 minutes of walking, and sedentary elderly showed a slightly larger step width coefficient of variation (~2%) at 10 min than active elderly. Active elderly showed higher walk ratio (step length/cadence) than sedentary in all times of walking, but the times did not differ in both the groups. In conclusion, treadmill gait kinematics differ between sedentary and active elderly, but changes over time are similar in sedentary and active elderly. As a practical implication, 30 min of walking might be a good strategy of exercise for elderly, independently of the fitness level, because it did not increase variability in step and stride kinematics, which is considered a risk of fall in this population.


Assuntos
Marcha/fisiologia , Caminhada/fisiologia , Acidentes por Quedas , Idoso , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Aptidão Física/fisiologia , Fatores de Risco , Comportamento Sedentário , Fatores de Tempo
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