Fluent performance has been described as the retention, endurance, stability, and application of the material learned. Fluent performers not only respond quickly during training, they also make many correct responses during training. The current study used a within-subject design to analyze the effects of increased response rates on Retention, Endurance, Stability, and Application tests. Number of correct responses and number of unprompted, correct responses in error correction procedures were yoked for individual participants across an Accuracy-plus-Rate training condition and an Accuracy-Only training condition. One participant scored better in tests that followed the Accuracy-Only condition. One participant showed results that slightly favor the Accuracy-plus-Rate training condition. The two participants whose response rates were successfully reduced in the Accuracy-Only condition performed better on all tests that followed the Accuracy-plus-Rate condition.

A literatura recente sugere que a fadiga mental piora o desempenho de atletas durante testes contrarrelógio (TT) de ciclismo. Assim o objetivo deste estudo foi verificar se a cafeína poderia reverter ou bloquear os efeitos negativos da fadiga mental em um contrarrelógio de 20km (TT20km). Métodos: Doze ciclistas treinados, com experiência em TT há pelo menos 2 anos, e nível de performance > 3 (34.3 ± 6.2 anos; 179.3 ± 5.1 cm; 77.6 ± 6.8 kg; 13.8 ± 4.5 % de gordura corporal; 58.9 ± 6.2 ml.kg-1.min-1; 367.0 ± 32.5 WPEAK), realizaram cinco visitas ao laboratório: 1) PRELIMINAR: para seleção dos sujeitos e familiarização com os instrumentos; 2) CONTROLE: foram realizadas três contrações voluntárias isométrica máxima (CVM), cujo maior torque encontrado entre elas definirá o valor de 70% para contração voluntária isométrica submáxima (CVIS) nas sessões seguintes. Posteriormente a CVIS, foi realizado o TT20km sem manipulação cognitiva ou suplementação; 3) FADIGA MENTAL (FM): execução do teste de atenção sustentada (RVIP), CVIS e TT20km respectivamente; 4) PLACEBO: ingestão da cápsula de placebo (FM + PLA) em seguida teste de RVIP, CVIS e TT20km; 5) CAFEÍNA: ingestão de cafeína (FM + CAF), consequentemente realizaram o teste de RVIP, CVIS e o TT20km). A atividade cerebral do córtex pré-frontal e córtex motor primário foi analisada por meio de eletroencefalografia (EEG) registrada antes e depois do teste RVIP. Igualmente, EEG do córtex pré-frontal e motor primário foi registrada durante uma contração voluntária isométrica submáxima, realizada antes do TT20km. Para as análises de comparações entre pré e pós tarefa cognitiva de atenção sustentada utilizou-se um teste T-student. Para as comparações múltiplas analisou-se por modelo misto entre a condição e a distância no TT20km, quando necessário o teste de Bonferroni foi utilizado. Resultados: CAF melhorou o desempenho em ciclistas mentalmente fatigados em ~ 1.8 % para FM e ~ 1.7 % para PLA (p = 0.00) e aumentou ~ 4.4 % para FM e ~ 3.6 % do que o placebo de WMEAN em FM + CAF (p = 0,00). A ativação cortical aumentou em ~ 4.8 % nas ondas teta de EEG após teste RVIP em FM e reduziu em FM + CAF ~ 8.8 % e FM + PLA ~ 4.8%. A razão entre PSE e WMEAN foi menor em FM + CAF do que nas outras condições (p = 0.01). Os ciclistas apresentaram maior motivação nos primeiros 2 km em FM + CAF comparado a FM e FM + PLA (p = 0.02) e maior afeto nos últimos 2 km em FM e FM + CAF do que FM + PLA (p = 0.01). Uma menor ativação cortical durante a CVIS e uma maior eficiência neuromuscular foi identificada na condição FM + CAF (p = 0.03). Conclusão: A CAF bloqueou os efeitos negativos da fadiga mental no CPF, melhorou o desempenho, diminuiu a PSE durante TT20km e aumentou a eficiência neuromuscular / Recent literature suggests that mental fatigue worsens the performance of athletes during time trial (TT) cycling tests. Thus, the aim of this study was to verify if caffeine could reverse or block the negative effects of mental fatigue in a TT of 20km (TT20km). Methods: Twelve trained cyclists with experience in TT for at least 2 years, and performance level > 3 (34.3 ± 6.2 years, 179.3 ± 5.1 cm, 77.6 ± 6.8 kg, 13.8 ± 4.5 % body fat 58.9 ± 6.2 ml .kg-1.min-1; 367.0 ± 32.5 WPEAK), carried out five visits at laboratory: 1) PRELIMINARY: for selection of subjects and familiarization with the instruments; 2) CONTROL: three maximal isometric voluntary contractions (CVM) were performed, the highest torque found between them will define the value of 70% for voluntary isometric submaximal contraction (CVIS) in the following sessions. After the CVIS, the TT20km will be performed without cognitive manipulation or supplementation; 3) MENTAL FATIGUE (FM): execution of the sustained attention test (RVIP), CVIS and TT20km respectively; 4) PLACEBO: placebo capsule intake (FM + PLA) then RVIP, CVIS and TT20km test; 5) CAFFEINE: caffeine intake (FM + CAF), consequently performed the RVIP, CVIS and TT20km tests). Brain activity of the prefrontal cortex and primary motor cortex will be analyzed by electroencephalography (EEG) recorded before and after the RVIP test. Likewise, EEG of the prefrontal cortex and primary motor will be recorded during a submaximal isometric voluntary contraction, performed before TT20km. For the analysis of comparisons between pre and post cognitive task of sustained attention was used a T-student test. For the multiple comparisons, the mixed model was analyzed for the condition and the distance in the TT20km, and the best matrix was identified for each case, when necessary the Bonferroni test was used. Results: CAF improved performance in mentally fatigued cyclists at ~ 1.8 % for FM and ~ 1.7 % for PLA (p = 0.00) and increased ~ 4.4% for FM and ~ 3.6% than WMEAN on FM + CAF (p = 0.00). Cortical activation increased by ~ 4.8 % in the theta EEG waves after RVIP test in FM and reduced in FM + CAF ~ 8.8 % and FM + PLA ~ 4.8 %. The ratio of RPE to WMEAN was lower in FM + CAF than in other conditions (p = 0.01). The ciclists started the TT20km more motivated in first 2 km (p = 0.02) and finished with more pleasure in the last 2km in FM and FM + CAF than in FM + PLA (p = 0.01). Lower cortical activation during CVIS and greater neuromuscular efficiency was identified in the FM + CAF condition (p = 0.03). Conclusion: CAF blocked the negative effects of mental fatigue on CPF, improved performance, decreased PSE over TT20km and increased neuromuscular efficiency

O treinamento concorrente (TC) é frequentemente utilizado por praticantes de atividades físicas e atletas com o intuito de desenvolver a força muscular e o condicionamento aeróbio. No entanto, essa estratégia de treinamento pode atenuar os ganhos de força e hipertrofia muscular em longo prazo, efeito este conhecido como fenômeno da interferência. Há indícios na literatura de que a magnitude da interferência pode ser dependente do volume em que o exercício aeróbio é realizado. Assim, o objetivo do presente estudo foi verificar o efeito do exercício aeróbio realizado com diferentes volumes no desempenho agudo de força máxima e de resistência de força dos membros inferiores. Homens fisicamente ativos (n=21) foram submetidos a seis condições experimentais realizadas em ordem aleatória, sendo três sessões de exercício aeróbio com volumes distintos (3km, 5km e 7km) seguidas pelo teste de força dinâmica máxima (1RM) e outras três sessões de exercício aeróbio com os volumes distintos seguidas pelo teste de resistência de força (4 séries de repetições máximas a 80% 1RM). Para o exercício aeróbio foi realizada a corrida contínua em esteira rolante a 90% do limiar anaeróbio (Lan) e os testes de força foram realizados no exercício leg press 45o. Para a comparação dos valores de 1RM, volume total (VT) e número de repetições máximas (NRM) da sessão de treinamento de força (TF) foi realizada uma análise de modelo misto tendo os volumes do exercício aeróbio como fator fixo e sujeitos como fator aleatório. Testes post-hoc com ajustamento de Tukey foram utilizados para comparações múltiplas. O nível de significância adotado foi de 5%. Não foram observadas diferenças nos valores de 1RM entre as condições. O VT e NRM das condições de 5km e 7km foram menores quando comparados com a condição controle. Ao passo que, o VT da condição de 7km foi menor em relação ao VT das condições de 3km e 5km; e o NRM da condição de 7km foi menor em relação ao NRM da condição de 3km. Não foram observadas diferenças no VT e NRM entre as condições de 3km e controle e entre as condições de 3km e 5km. Em conclusão, o desempenho da resistência de força foi prejudicado após a realização do exercício aeróbio e a ocorrência e a magnitude desta interferência dependeram do volume em que o exercício aeróbio foi realizado. Adicionalmente, o desempenho da força dinâmica máxima não foi prejudicado pela realização prévia do exercício aeróbio / Concurrent training (CT) is frequently utilized by physically active individuals and athletes in order to develop muscle strength and aerobic fitness. However, this training strategy may result in attenuation of the gains on strength and muscle hypertrophy in long term. This effect has been referred to as the interference phenomenon. There are indications that the magnitude of this interference may be dependent on the volume that aerobic exercise is performed. Thus, the aim of the present study was to verify the effect of aerobic exercise performed with different volumes on the acute performance of lower limbs maximum strength and strength endurance. Physically active men (n=21) were submitted to six experimental conditions performed in random order, three aerobic exercise sessions with different volumes (3km, 5km and 7km) followed by the maximum dynamic strength (1RM) test and three aerobic exercise sessions with different volumes followed by strength endurance test (4 sets of maximum repetitions at 80% 1RM). The aerobic exercise was a continuous treadmill run at 90% of the anaerobic threshold (AT) and all strength tests were performed in the leg press 45o. A mixed-model analysis with the volumes of aerobic exercise as a fixed factor and subject as a random factor was performed to compare 1RM values, total volume (TV) and maximum number of repetitions (MNR) of the strength training (ST) session. Post-hoc tests with Tukey adjustments were used for multiple comparisons. The significance level adopted was 5%. No differences were observed in 1RM values among conditions. The TV and MNR of the 5km and 7km conditions were lower when compared to the control condition. The TV of the 7km condition was lower than the 3km and 5km conditions; and the MNR of the 7km condition was lower than the 3km condition. No differences were observed in TV and MNR between the 3km and control conditions and between the 3km and 5km conditions. In conclusion, strength endurance performance was impaired when performed after aerobic exercise and the magnitude of this interference depended on the volume of the aerobic exercise. In addition, maximum dynamic strength performance was not affected by prior execution of aerobic exercise

No description available.

No description available.

Abstract available in the Medicine & Science in Sports & Exercise.

The objective of this doctoral thesis is to develop, engineer and investigate an amorphous metal tungsten nitride (aWNx) and to study its functionality for applications focused on electromechanical system at the nano-scale. Charge transport based solid state device oriented complementary metal oxide semiconductor (CMOS) electronics have reached a level where they are scaled down to nearly their fundamental limits regarding switching speed, off state power consumption and the on state power consumption due to the fundamental limitation of sub-threshold slope (SS) remains at 60 mV/dec. NEM switch theoretically and practically offers the steepest sub-threshold slope and practically has shown zero static power consumption due to their physical isolation originated from the nature of their mechanical operation. Fundamental challenges remain with NEM switches in context of their performance and reliability: (i) necessity of lower pull-in voltage comparable to CMOS technology; (ii) operation in ambient/air; (iii) increased ON current and decreased ON resistance; (iv) scaling of devices and improved mechanical and electrical contacts; and (v) high endurance. The “perfect” NEM switch should overcome all the above-mentioned challenges. Here, we show such a NEM switch fabricated with aWNx to show (i) sub-0.3-volt operation; (ii) operation in air and vacuum; (iii) ON current as high as 0.5 mA and ON resistance lower than 5 kΩ; (iv) improved mechanical contact; and the most importantly (v) continuous switching of 8 trillion cycles for more than 10 days with the highest switching speed is 30 nanosecond without hysteresis. In addition, tungsten nitride could be the modern life vine by fulfilling the demand of biodegradable material for sustainable life regime. Transient electronics is a form of biodegradable electronics as it is physically disappearing totally or partially after performing the required function. The fabricated aWNx suites this category very well, despite not being a universal bio-element. It has been found that aWNx dissolves in ground water with a rate of ≈ 20-60 nm h-1. This means that a 100 nm thick aWNx disappears in ground water in less than a day and three days are enough to dissolve completely a 300 nm thickness device.

The purpose of this review is twofold: to elucidate the utility of resistance training for endurance athletes, and provide the practitioner with evidenced-based periodization strategies for concurrent strength and endurance training in athletic populations. Both low-intensity exercise endurance (liee) and high-intensity exercise endurance (hiee) have been shown to improve as a result of maximal, high force, low velocity (hflv) and explosive, low-force, high-velocity strength training. Hflv strength training is recommended initially to develop a neuromuscular base for endurance athletes with limited strength training experience. A sequenced approach to strength training involving phases of strength-endurance, basic strength, strength, and power will provide further enhancements in liee and hiee for high-level endurance athletes.

This thesis deals with the design of a crankshaft for a high power racing engine using modern technology. It covers all of the steps from a brief research, design, torsional vibration analysis to fatigue calculation using FEA and MBS models.

Title: Effects of minimal dose of resistance training on body composition and running performance in female recreational runners Objective: The purpose of this study was to analyse the extent to which minimal dose resistance training would elicit improvements in running performance and body composition for female recreational runners. Methods: Forty-one female recreational runners were randomly assigned to one of three groups (endurance running [V] n=14; combined endurance running and resistance training program once [VR30] n=14 and twice a week [VR60] n=13, respectively). During the 10-week training program, the V group completed 3 hours of continuous endurance running per week; VR30 completed 2 ½ hours of continuous endurance running and 1 x 30 min of resistance training per week, while VR60 group completed 2 hours of continuous endurance running and 2x30 min of resistance training per week. Body composition (FM, FFM, ECM/BCM), standing long jump, running economy, ventilatory anaerobic threshold and maximal endurance performance characteristics were assessed using ANOVA with repeated measures. Body composition was assessed via whole-body bio impedance. Performance parameters were determined during running on a treadmill. Results: Thirty-one female recreational runners completed 10-week...