Ana Paula da Silva Azevedo | USP (original) (raw)
Papers by Ana Paula da Silva Azevedo
O objetivo deste estudo é analisar a influência de dois modelos distintos de calçado esportivo fa... more O objetivo deste estudo é analisar a influência de dois modelos distintos de calçado esportivo falsificado (indoor e jogging) sobre características dinâmicas e eletromiográficas da locomoção humana. Oito voluntários participaram do estudo, dos quais cinco realizaram os testes com os calçados do modelo indoor e três realizaram os testes com os calçados do modelo jogging, testando a versão original e falsificada de seus respectivos modelos de calçado durante a marcha e a corrida. Foram coletados dados referentes à força de reação do solo (FRS) (esteira com plataformas de força - Sistema GAITWAY) e à atividade eletromiográfica (EMG 1000 Sistema Lynx). Os resultados mostram o aumento de Fy1, Imp50 e Imp75 durante a marcha, e o aumento de Fy1 e GC1 durante a corrida com o uso do calçado falsificado indoor, caracterizando situações de maior sobrecarga e influência negativa deste calçado. Ao usar-se o calçado falsificado indoor, observou-se também alteração no envoltório linear dos músculo...
Bruno Mezêncio, João Gustavo Claudino, Alberto Carlos Amadio, Julio Cerca Serrão, Leszek Antoni S... more Bruno Mezêncio, João Gustavo Claudino, Alberto Carlos Amadio, Julio Cerca Serrão, Leszek Antoni Szmuchrowski and Rudolf Huebner Laboratory of Biomechanics, School of Physical Educ ation and Sport, University of São Paulo, São Paulo , Brazil Laboratory of Load Evaluation, Federal University o f Minas Gerais, Belo Horizonte, Brazil Laboratory of Bioengineering, Department of Mechani c l Engineering, Federal University of Minas Gerai s, Belo Horizonte, Brazil email: mezencio@usp.br
Sports Biomechanics, 2019
Perception of external loads may be a central topic to understand adjustments to the mechanical d... more Perception of external loads may be a central topic to understand adjustments to the mechanical demands during movement. Nevertheless, the association between the perceived and the real load received is still controversial. This study aimed to correlate vertical ground reaction force (vGRF) to the perception of impact in different regimens of stimulus application. Ten physically active men performed drop jumps from four different heights (0.20, 0.40, 0.60 and 0.80 m). A force plate measured the vGRF, while perception of impact was evaluated through Borg's Ratings of Perceived Exertion. Higher values of maximum vGRF (Fy_max) and impulse of the first 50 ms (I_50), and reduced time to reach Fy_max indicate increased external forces as drop jump height raised. Perception of impact increased gradually with increasing jump height for I_50. Fy_max and I_50 showed moderate to strong correlations to perceived load for 70% and 90% of participants, respectively. Higher and different intensity of stimulus facilitated the perception of impact, presenting moderate to strong correlations to kinetic parameters related to external load during landing from drop jump. Perception of higher impacts could be used as a surrogate to monitor 'real' impacts and possibly also for managing impact-related injury risk.
Cytokine, 2020
The study investigated the immediate effect of a moderate interval-running training session on ci... more The study investigated the immediate effect of a moderate interval-running training session on circulating inflammatory cytokines concentration at real conditions of training. Nine recreational runners (5 women and 4 men; 68,33 ± 10,20 kg; 1,65 ± 0,07 m; 28,67 ± 4,24 years) had blood samples collected from antecubital vein before and immediately after a moderate interval-running training session without fasting. Cytokine levels were obtained from blood samples through Multiplex Analysis of Sample Protein Content, performed by Magpix® instrument. The assay detected the cytokines and calculated the plasma cytokine concentrations. Reduced concentration was observed after training session for all cytokines (p < 0.05), except for IP-10. Moderate effect sizes were identified in IL-6, IL-8, TNF-α, IP-10, MCP1 and GM-CSF. In summary, a single moderate intervalrunning training session at real conditions of training seems not to be stressing enough to increase cytokine levels as a response to the exercise. Results reinforce that immediate biochemical response and inflammatory modulation related to exercise is dose-dependent and may be influenced by other variables.
Revista corpoconsciência, Jul 28, 2021
Resumo Este estudo investigou o efeito agudo da corrida descalço sobre parâmetros selecionados da... more Resumo Este estudo investigou o efeito agudo da corrida descalço sobre parâmetros selecionados das componentes anteroposterior e mediolateral da Força de Reação do Solo (FRS) em corredores habituados ao uso do calçado esportivo. Setenta e um corredores recreacionais, inexperientes em corrida descalço, correram em velocidade autoselecionada por uma distância de 9 metros em piso fixo equipado com plataformas de força, sob duas condições: calçados e descalços. Os picos de frenagem e aceleração da componente anteroposterior, bem como os picos Azevedo e colaboradores
Revista corpoconsciência, Jul 28, 2021
Resumo A corrida é uma prática largamente utilizada por aqueles que almejam manter ou aprimorar a... more Resumo A corrida é uma prática largamente utilizada por aqueles que almejam manter ou aprimorar a aptidão física. O treinamento de força tem sido recomendado como forma de aumentar o desempenho e reduzir o risco de lesão em praticantes de corrida, no entanto, a relação entre força muscular e mecânica da corrida ainda necessita de Lima e colaboradores
Many studies have investigated the infl uence of running shoes on motion pattern (CLARKE, FREDERI... more Many studies have investigated the infl uence of running shoes on motion pattern (CLARKE, FREDERICK & COOPER, 1983; LUETHI, DENOTH, KAELIN, STACOFF & STUESSI, 1987; NIGG, BAHLSEN, LUETHI & STOKES, 1987; WIEGERINCK, BOYD, YODER, ABBEY, NUNLEY & QUEE, 2009), but it is yet not clear when the running shoes loses its ability to reduce impact forces during running and therefore leading to the replacement of the running shoe by a new one. There is evidence that long distance running lead to repeated compressions on the shoes structure that can cause ruptures on EVA air cells and damage the midsole’s foam (VERDEJO & MILLS, 2004). Apparently, these damages reduce its capacity to damp the impact forces (COOK, KESTER & BRUNET, 1985; DIXON, 2008). The usage imposed by runners wearing the shoes resulted in a decrease in impact attenuation of 20% after 150 miles (241 km) and of 30% at the end of 500 miles (805 km) of running (COOK, KESTER & BRUNET, 1985). This reduction in impact attenuation was ...
O futebol vem se tornando cada vez mais competitivo, consequentemente o rendimento dos clubes aum... more O futebol vem se tornando cada vez mais competitivo, consequentemente o rendimento dos clubes aumentaram na mesma proporcao. O objetivo do presente estudo foi identificar os modelos que melhor explicam as relacoes entre as diferentes variaveis do scout dos jogos da Copa Libertadores da America realizada em 2014. Foi considerado para analise o scout dos 126 jogos da competicao. Os dados foram extraidos do site oficial da CONMEMBOL e do site Footstats. Os resultados indicaram que os modelos para as variaveis gols feitos (r 2 =0,754), finalizacoes (r 2 =0,707), posse de bola (r 2 =0,528) e saldo de gols (r 2 =0,500) foram significativos (p<0,05). Conclui-se que a comissao tecnica poderia dar mais enfase para os GF, FI, PB e SG, de forma a facilitar o entendimento dos scouts e sua aplicacao no planejamento da equipe. PALAVRAS-CHAVE: Futebol; Copa Libertadores da America; analise de jogo; scout.
Medicine & Science in Sports & Exercise
Human Movement
Purpose. Excessive external load is a likely cause of running injuries. Although minimal running ... more Purpose. Excessive external load is a likely cause of running injuries. Although minimal running has been suggested as a possible approach to reduce impact and injury risk, an abrupt transition from conventional shoes to minimal running is also related to injuries. therefore, the partial minimalist shoe has been suggested as a training strategy for a safe transition to minimal running. the study investigated if 8 weeks of training in partial minimalist shoe could improve impact control of shod and barefoot running. Methods. recreational runners (12 men, 2 women), inexperienced in minimal running, performed 3 training sessions/week in partial minimalist shoes for 8 weeks. Before and after the intervention, the participants ran on a treadmill at 2.5 m/s under two conditions: in their habitual shoes and barefoot. Vertical ground reaction force (VGrF) was recorded. Results. After the intervention, reduced values of the first peak (16.7% for shod, 36.7% for barefoot), time to reach the first peak (7.7% for shod, 30.2% for barefoot), and the load rate of the first peak (9.8% for shod, 9.5% for barefoot) were observed for both conditions (p < 0.001). Six subjects dropped out from the intervention. Conclusions. Partial minimalist training improved VGrF variables related to shock attenuation. thus, the 8-week running training program with partial minimalist shoes was an effective approach to increase impact control. the intervention reduced the impact force in both shod and barefoot running, arising as a feasible option to progressively transition to minimal running.
Nutrition
OBJECTIVES This study aimed to investigate the effects of creatine (Cr) supplementation on biomec... more OBJECTIVES This study aimed to investigate the effects of creatine (Cr) supplementation on biomechanical parameters related to shock attenuation during a session of high-intensity interval training (HIIT). METHODS A single-blinded, placebo-controlled, crossover design was adopted to test eight male elite soccer players during HIIT sessions under two conditions: after placebo supplementation and after Cr supplementation. HIIT test sessions consisted of an intermittent test (five bouts of running) with a constant load applied until exhaustion was reached. The vertical component of ground reaction force and electromyography data were recorded by Gaitway and Lynx-EMG Systems, respectively. Heart rate, rated perceived exertion (Borg's Scale) and lactate concentration information were also obtained. RESULTS Cr supplementation did not affect heart rate, rated perceived exertion, and lactate concentration. Decreased values of magnitude of the first peak of the vertical component of ground reaction force (17.2-24.2%) and impulse of the first 50 ms (Imp50; 34.3%) were observed for Cr, but higher values of time to reach the first peak were detected for Cr compared with placebo. Significant modifications in muscle activation were also observed, mainly in the pre-activation phase, and changes were observed in intermediary bouts. CONCLUSIONS Cr supplementation has the potential to influence biomechanical parameters related to impact control during a single session of HIIT based on running. In particular, the findings of the current study indicate possible improvements in shock attenuation and a safer practice of HIIT under Cr supplementation.
PloS one, 2016
Short-term effects of barefoot and simulated barefoot running have been widely discussed in recen... more Short-term effects of barefoot and simulated barefoot running have been widely discussed in recent years. Consequences of adopting barefoot running for a long period, including as a training approach, still remain unknown. The present study evaluated the influence of 16 weeks of progressive barefoot running training on impact force and muscle activation in habitual shod runners. Six habitual shod runners (3 men and 3 women, 29.5 ± 7.3 years) were tested barefoot (BF) and shod (SH), before and after 16 weeks of progressive barefoot running training. Tests consisted of running on instrumented treadmill at 9 km/h, for 10 minutes in each experimental condition. Nine data acquisitions (10 s) of vertical ground reaction force (VGRF) and electromyographic (EMG) signal were conducted in each experimental condition for each test. BF training was effective to alter VGRF and EMG parameters of running in habitual shod runners, regardless of footwear condition (SH or BF). The magnitude of first ...
Journal of Strength and Conditioning Research, 2015
The purpose of this study was to investigate the effects of running drills during an interval tra... more The purpose of this study was to investigate the effects of running drills during an interval training program on biomechanical parameters of running. Thirty recreational runners, divided into 2 groups (control group and experimental group [EG]), were submitted to a 15-week interval training, but only EG performed running drills in the training. The test sessions were accomplished before and after intervention. Spatiotemporal and kinetic variables were analyzed at 2 speeds: maximum (Smax) and comfortable (Scomf). For moment effect, significant increases were observed for Scomf (8.9%) and Smax (10.7%) after training. Variables related to mechanical load were also higher after training for both speeds (LR1: 16.4% and Imp75: 7.8% at Scomf; LR1: 21.4% and Imp75: 8.1% at Smax). For training approach effect, higher value of Imp75 was observed in EG (10.1% at Scomf and 11.9% at Smax, without performance improvements). Also, EG presented higher values of Fy2 (6.7% at Scomf and 6.1% at Smax) and FT (13.3% at Scomf), variables related to the center of mass oscillation. As a conclusion, including running drills in a 15-week interval running training seems not to be an efficient procedure to improve parameters related to mechanical load and performance.
Short-term effects of barefoot and simulated barefoot running have been widely discussed in recen... more Short-term effects of barefoot and simulated barefoot running have been widely discussed in recent years. Consequences of adopting barefoot running for a long period, including as a training approach, still remain unknown. The present study evaluated the influence of 16 weeks of progressive barefoot running training on impact force and muscle activation in habitual shod runners. Six habitual shod runners (3 men and 3 women, 29.5 ± 7.3 years) were tested barefoot (BF) and shod (SH), before and after 16 weeks of progressive barefoot running training. Tests consisted of running on instrumented treadmill at 9 km/h, for 10 minutes in each experimental condition. Nine data acquisitions (10 s) of vertical ground reaction force (VGRF) and electromyographic (EMG) signal were conducted in each experimental condition for each test. BF training was effective to alter VGRF and EMG parameters of running in habitual shod runners, regardless of footwear condition (SH or BF). The magnitude of first peak of VGRF (Fy1) and the impulse of the first 50 ms decreased after training for BF and SH (p<0.01). The activation reduced from PRE to POST training for four muscles in BF running (p<0.001), whereas only muscle gastrocnemius lateralis decreased significantly its activation (p<0.01) in SH running. A 16-week progressive barefoot running training seems to be an effective training strategy to reduce impact force, improve shock attenuation and to decrease muscle activation intensity, not only in BF running, but also in SH running, although BF condition seems to be more influenced by BF training.
Revista Brasileira de Medicina do Esporte, 2016
Revista Brasileira De Educacao Fisica E Esporte, Dec 1, 2013
The purpose of this study was to analyze the kinetic responses of running shoes submitted to prol... more The purpose of this study was to analyze the kinetic responses of running shoes submitted to prolonged use. Four shoes (R1, R2, T1 and T2) were used for 500 km except for T1 which was used for 1000 km. At every 100 km, Ground Reaction Force (GRF) and plantar pressure measurements were collected. In T2, there was a slight trend of increase in Loading Rate of the fi rst peak of GRF with increasing distance. R1, R2 and T1 showed no trend of increase in Loading Rate values. Shoe T1 showed a slight tendency of increase in Loading Rate values when the distance was considered up to 1000 km. All running shoes showed a high variability in peak pressure values, but no trend of increase was observed. On the contrary, T1, T2 and R2 showed a trend of decrease in peak pressure values with increasing use. Therefore, there is no consistent evidence or trend of increase in Loading Rate and Peak Pressure values that would suggest worsening in external load attenuation.
Revista Brasileira De Educacao Fisica E Esporte, Dec 1, 2013
The purpose of this study was to analyze the kinetic responses of running shoes submitted to prol... more The purpose of this study was to analyze the kinetic responses of running shoes submitted to prolonged use. Four shoes (R1, R2, T1 and T2) were used for 500 km except for T1 which was used for 1000 km. At every 100 km, Ground Reaction Force (GRF) and plantar pressure measurements were collected. In T2, there was a slight trend of increase in Loading Rate of the fi rst peak of GRF with increasing distance. R1, R2 and T1 showed no trend of increase in Loading Rate values. Shoe T1 showed a slight tendency of increase in Loading Rate values when the distance was considered up to 1000 km. All running shoes showed a high variability in peak pressure values, but no trend of increase was observed. On the contrary, T1, T2 and R2 showed a trend of decrease in peak pressure values with increasing use. Therefore, there is no consistent evidence or trend of increase in Loading Rate and Peak Pressure values that would suggest worsening in external load attenuation.
O objetivo deste estudo é analisar a influência de dois modelos distintos de calçado esportivo fa... more O objetivo deste estudo é analisar a influência de dois modelos distintos de calçado esportivo falsificado (indoor e jogging) sobre características dinâmicas e eletromiográficas da locomoção humana. Oito voluntários participaram do estudo, dos quais cinco realizaram os testes com os calçados do modelo indoor e três realizaram os testes com os calçados do modelo jogging, testando a versão original e falsificada de seus respectivos modelos de calçado durante a marcha e a corrida. Foram coletados dados referentes à força de reação do solo (FRS) (esteira com plataformas de força - Sistema GAITWAY) e à atividade eletromiográfica (EMG 1000 Sistema Lynx). Os resultados mostram o aumento de Fy1, Imp50 e Imp75 durante a marcha, e o aumento de Fy1 e GC1 durante a corrida com o uso do calçado falsificado indoor, caracterizando situações de maior sobrecarga e influência negativa deste calçado. Ao usar-se o calçado falsificado indoor, observou-se também alteração no envoltório linear dos músculo...
Bruno Mezêncio, João Gustavo Claudino, Alberto Carlos Amadio, Julio Cerca Serrão, Leszek Antoni S... more Bruno Mezêncio, João Gustavo Claudino, Alberto Carlos Amadio, Julio Cerca Serrão, Leszek Antoni Szmuchrowski and Rudolf Huebner Laboratory of Biomechanics, School of Physical Educ ation and Sport, University of São Paulo, São Paulo , Brazil Laboratory of Load Evaluation, Federal University o f Minas Gerais, Belo Horizonte, Brazil Laboratory of Bioengineering, Department of Mechani c l Engineering, Federal University of Minas Gerai s, Belo Horizonte, Brazil email: mezencio@usp.br
Sports Biomechanics, 2019
Perception of external loads may be a central topic to understand adjustments to the mechanical d... more Perception of external loads may be a central topic to understand adjustments to the mechanical demands during movement. Nevertheless, the association between the perceived and the real load received is still controversial. This study aimed to correlate vertical ground reaction force (vGRF) to the perception of impact in different regimens of stimulus application. Ten physically active men performed drop jumps from four different heights (0.20, 0.40, 0.60 and 0.80 m). A force plate measured the vGRF, while perception of impact was evaluated through Borg's Ratings of Perceived Exertion. Higher values of maximum vGRF (Fy_max) and impulse of the first 50 ms (I_50), and reduced time to reach Fy_max indicate increased external forces as drop jump height raised. Perception of impact increased gradually with increasing jump height for I_50. Fy_max and I_50 showed moderate to strong correlations to perceived load for 70% and 90% of participants, respectively. Higher and different intensity of stimulus facilitated the perception of impact, presenting moderate to strong correlations to kinetic parameters related to external load during landing from drop jump. Perception of higher impacts could be used as a surrogate to monitor 'real' impacts and possibly also for managing impact-related injury risk.
Cytokine, 2020
The study investigated the immediate effect of a moderate interval-running training session on ci... more The study investigated the immediate effect of a moderate interval-running training session on circulating inflammatory cytokines concentration at real conditions of training. Nine recreational runners (5 women and 4 men; 68,33 ± 10,20 kg; 1,65 ± 0,07 m; 28,67 ± 4,24 years) had blood samples collected from antecubital vein before and immediately after a moderate interval-running training session without fasting. Cytokine levels were obtained from blood samples through Multiplex Analysis of Sample Protein Content, performed by Magpix® instrument. The assay detected the cytokines and calculated the plasma cytokine concentrations. Reduced concentration was observed after training session for all cytokines (p < 0.05), except for IP-10. Moderate effect sizes were identified in IL-6, IL-8, TNF-α, IP-10, MCP1 and GM-CSF. In summary, a single moderate intervalrunning training session at real conditions of training seems not to be stressing enough to increase cytokine levels as a response to the exercise. Results reinforce that immediate biochemical response and inflammatory modulation related to exercise is dose-dependent and may be influenced by other variables.
Revista corpoconsciência, Jul 28, 2021
Resumo Este estudo investigou o efeito agudo da corrida descalço sobre parâmetros selecionados da... more Resumo Este estudo investigou o efeito agudo da corrida descalço sobre parâmetros selecionados das componentes anteroposterior e mediolateral da Força de Reação do Solo (FRS) em corredores habituados ao uso do calçado esportivo. Setenta e um corredores recreacionais, inexperientes em corrida descalço, correram em velocidade autoselecionada por uma distância de 9 metros em piso fixo equipado com plataformas de força, sob duas condições: calçados e descalços. Os picos de frenagem e aceleração da componente anteroposterior, bem como os picos Azevedo e colaboradores
Revista corpoconsciência, Jul 28, 2021
Resumo A corrida é uma prática largamente utilizada por aqueles que almejam manter ou aprimorar a... more Resumo A corrida é uma prática largamente utilizada por aqueles que almejam manter ou aprimorar a aptidão física. O treinamento de força tem sido recomendado como forma de aumentar o desempenho e reduzir o risco de lesão em praticantes de corrida, no entanto, a relação entre força muscular e mecânica da corrida ainda necessita de Lima e colaboradores
Many studies have investigated the infl uence of running shoes on motion pattern (CLARKE, FREDERI... more Many studies have investigated the infl uence of running shoes on motion pattern (CLARKE, FREDERICK & COOPER, 1983; LUETHI, DENOTH, KAELIN, STACOFF & STUESSI, 1987; NIGG, BAHLSEN, LUETHI & STOKES, 1987; WIEGERINCK, BOYD, YODER, ABBEY, NUNLEY & QUEE, 2009), but it is yet not clear when the running shoes loses its ability to reduce impact forces during running and therefore leading to the replacement of the running shoe by a new one. There is evidence that long distance running lead to repeated compressions on the shoes structure that can cause ruptures on EVA air cells and damage the midsole’s foam (VERDEJO & MILLS, 2004). Apparently, these damages reduce its capacity to damp the impact forces (COOK, KESTER & BRUNET, 1985; DIXON, 2008). The usage imposed by runners wearing the shoes resulted in a decrease in impact attenuation of 20% after 150 miles (241 km) and of 30% at the end of 500 miles (805 km) of running (COOK, KESTER & BRUNET, 1985). This reduction in impact attenuation was ...
O futebol vem se tornando cada vez mais competitivo, consequentemente o rendimento dos clubes aum... more O futebol vem se tornando cada vez mais competitivo, consequentemente o rendimento dos clubes aumentaram na mesma proporcao. O objetivo do presente estudo foi identificar os modelos que melhor explicam as relacoes entre as diferentes variaveis do scout dos jogos da Copa Libertadores da America realizada em 2014. Foi considerado para analise o scout dos 126 jogos da competicao. Os dados foram extraidos do site oficial da CONMEMBOL e do site Footstats. Os resultados indicaram que os modelos para as variaveis gols feitos (r 2 =0,754), finalizacoes (r 2 =0,707), posse de bola (r 2 =0,528) e saldo de gols (r 2 =0,500) foram significativos (p<0,05). Conclui-se que a comissao tecnica poderia dar mais enfase para os GF, FI, PB e SG, de forma a facilitar o entendimento dos scouts e sua aplicacao no planejamento da equipe. PALAVRAS-CHAVE: Futebol; Copa Libertadores da America; analise de jogo; scout.
Medicine & Science in Sports & Exercise
Human Movement
Purpose. Excessive external load is a likely cause of running injuries. Although minimal running ... more Purpose. Excessive external load is a likely cause of running injuries. Although minimal running has been suggested as a possible approach to reduce impact and injury risk, an abrupt transition from conventional shoes to minimal running is also related to injuries. therefore, the partial minimalist shoe has been suggested as a training strategy for a safe transition to minimal running. the study investigated if 8 weeks of training in partial minimalist shoe could improve impact control of shod and barefoot running. Methods. recreational runners (12 men, 2 women), inexperienced in minimal running, performed 3 training sessions/week in partial minimalist shoes for 8 weeks. Before and after the intervention, the participants ran on a treadmill at 2.5 m/s under two conditions: in their habitual shoes and barefoot. Vertical ground reaction force (VGrF) was recorded. Results. After the intervention, reduced values of the first peak (16.7% for shod, 36.7% for barefoot), time to reach the first peak (7.7% for shod, 30.2% for barefoot), and the load rate of the first peak (9.8% for shod, 9.5% for barefoot) were observed for both conditions (p < 0.001). Six subjects dropped out from the intervention. Conclusions. Partial minimalist training improved VGrF variables related to shock attenuation. thus, the 8-week running training program with partial minimalist shoes was an effective approach to increase impact control. the intervention reduced the impact force in both shod and barefoot running, arising as a feasible option to progressively transition to minimal running.
Nutrition
OBJECTIVES This study aimed to investigate the effects of creatine (Cr) supplementation on biomec... more OBJECTIVES This study aimed to investigate the effects of creatine (Cr) supplementation on biomechanical parameters related to shock attenuation during a session of high-intensity interval training (HIIT). METHODS A single-blinded, placebo-controlled, crossover design was adopted to test eight male elite soccer players during HIIT sessions under two conditions: after placebo supplementation and after Cr supplementation. HIIT test sessions consisted of an intermittent test (five bouts of running) with a constant load applied until exhaustion was reached. The vertical component of ground reaction force and electromyography data were recorded by Gaitway and Lynx-EMG Systems, respectively. Heart rate, rated perceived exertion (Borg's Scale) and lactate concentration information were also obtained. RESULTS Cr supplementation did not affect heart rate, rated perceived exertion, and lactate concentration. Decreased values of magnitude of the first peak of the vertical component of ground reaction force (17.2-24.2%) and impulse of the first 50 ms (Imp50; 34.3%) were observed for Cr, but higher values of time to reach the first peak were detected for Cr compared with placebo. Significant modifications in muscle activation were also observed, mainly in the pre-activation phase, and changes were observed in intermediary bouts. CONCLUSIONS Cr supplementation has the potential to influence biomechanical parameters related to impact control during a single session of HIIT based on running. In particular, the findings of the current study indicate possible improvements in shock attenuation and a safer practice of HIIT under Cr supplementation.
PloS one, 2016
Short-term effects of barefoot and simulated barefoot running have been widely discussed in recen... more Short-term effects of barefoot and simulated barefoot running have been widely discussed in recent years. Consequences of adopting barefoot running for a long period, including as a training approach, still remain unknown. The present study evaluated the influence of 16 weeks of progressive barefoot running training on impact force and muscle activation in habitual shod runners. Six habitual shod runners (3 men and 3 women, 29.5 ± 7.3 years) were tested barefoot (BF) and shod (SH), before and after 16 weeks of progressive barefoot running training. Tests consisted of running on instrumented treadmill at 9 km/h, for 10 minutes in each experimental condition. Nine data acquisitions (10 s) of vertical ground reaction force (VGRF) and electromyographic (EMG) signal were conducted in each experimental condition for each test. BF training was effective to alter VGRF and EMG parameters of running in habitual shod runners, regardless of footwear condition (SH or BF). The magnitude of first ...
Journal of Strength and Conditioning Research, 2015
The purpose of this study was to investigate the effects of running drills during an interval tra... more The purpose of this study was to investigate the effects of running drills during an interval training program on biomechanical parameters of running. Thirty recreational runners, divided into 2 groups (control group and experimental group [EG]), were submitted to a 15-week interval training, but only EG performed running drills in the training. The test sessions were accomplished before and after intervention. Spatiotemporal and kinetic variables were analyzed at 2 speeds: maximum (Smax) and comfortable (Scomf). For moment effect, significant increases were observed for Scomf (8.9%) and Smax (10.7%) after training. Variables related to mechanical load were also higher after training for both speeds (LR1: 16.4% and Imp75: 7.8% at Scomf; LR1: 21.4% and Imp75: 8.1% at Smax). For training approach effect, higher value of Imp75 was observed in EG (10.1% at Scomf and 11.9% at Smax, without performance improvements). Also, EG presented higher values of Fy2 (6.7% at Scomf and 6.1% at Smax) and FT (13.3% at Scomf), variables related to the center of mass oscillation. As a conclusion, including running drills in a 15-week interval running training seems not to be an efficient procedure to improve parameters related to mechanical load and performance.
Short-term effects of barefoot and simulated barefoot running have been widely discussed in recen... more Short-term effects of barefoot and simulated barefoot running have been widely discussed in recent years. Consequences of adopting barefoot running for a long period, including as a training approach, still remain unknown. The present study evaluated the influence of 16 weeks of progressive barefoot running training on impact force and muscle activation in habitual shod runners. Six habitual shod runners (3 men and 3 women, 29.5 ± 7.3 years) were tested barefoot (BF) and shod (SH), before and after 16 weeks of progressive barefoot running training. Tests consisted of running on instrumented treadmill at 9 km/h, for 10 minutes in each experimental condition. Nine data acquisitions (10 s) of vertical ground reaction force (VGRF) and electromyographic (EMG) signal were conducted in each experimental condition for each test. BF training was effective to alter VGRF and EMG parameters of running in habitual shod runners, regardless of footwear condition (SH or BF). The magnitude of first peak of VGRF (Fy1) and the impulse of the first 50 ms decreased after training for BF and SH (p<0.01). The activation reduced from PRE to POST training for four muscles in BF running (p<0.001), whereas only muscle gastrocnemius lateralis decreased significantly its activation (p<0.01) in SH running. A 16-week progressive barefoot running training seems to be an effective training strategy to reduce impact force, improve shock attenuation and to decrease muscle activation intensity, not only in BF running, but also in SH running, although BF condition seems to be more influenced by BF training.
Revista Brasileira de Medicina do Esporte, 2016
Revista Brasileira De Educacao Fisica E Esporte, Dec 1, 2013
The purpose of this study was to analyze the kinetic responses of running shoes submitted to prol... more The purpose of this study was to analyze the kinetic responses of running shoes submitted to prolonged use. Four shoes (R1, R2, T1 and T2) were used for 500 km except for T1 which was used for 1000 km. At every 100 km, Ground Reaction Force (GRF) and plantar pressure measurements were collected. In T2, there was a slight trend of increase in Loading Rate of the fi rst peak of GRF with increasing distance. R1, R2 and T1 showed no trend of increase in Loading Rate values. Shoe T1 showed a slight tendency of increase in Loading Rate values when the distance was considered up to 1000 km. All running shoes showed a high variability in peak pressure values, but no trend of increase was observed. On the contrary, T1, T2 and R2 showed a trend of decrease in peak pressure values with increasing use. Therefore, there is no consistent evidence or trend of increase in Loading Rate and Peak Pressure values that would suggest worsening in external load attenuation.
Revista Brasileira De Educacao Fisica E Esporte, Dec 1, 2013
The purpose of this study was to analyze the kinetic responses of running shoes submitted to prol... more The purpose of this study was to analyze the kinetic responses of running shoes submitted to prolonged use. Four shoes (R1, R2, T1 and T2) were used for 500 km except for T1 which was used for 1000 km. At every 100 km, Ground Reaction Force (GRF) and plantar pressure measurements were collected. In T2, there was a slight trend of increase in Loading Rate of the fi rst peak of GRF with increasing distance. R1, R2 and T1 showed no trend of increase in Loading Rate values. Shoe T1 showed a slight tendency of increase in Loading Rate values when the distance was considered up to 1000 km. All running shoes showed a high variability in peak pressure values, but no trend of increase was observed. On the contrary, T1, T2 and R2 showed a trend of decrease in peak pressure values with increasing use. Therefore, there is no consistent evidence or trend of increase in Loading Rate and Peak Pressure values that would suggest worsening in external load attenuation.