Browsing by Author "Faro, Ana"
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- Comparison of a 10 week resistance strength training program, in muscle morphology, electromyography activity and strength gains on prepubescent girls and boysPublication . Monteiro, A.M.; Lopes, Vitor P.; Faro, AnaThe mechanisms that are behind the strength gains, in strength training programs, are not still well evidenced. It seems to exist the certainty that strength training produces greater gains, during puberty and after, in virtue, over all, of the increase of serum testosterone, which allows an increase of muscle hypertrophy. Strength gains gotten before puberty, will be resultant of neurological adaptations, such as, the improvement of inter and intra-muscle coordination and order, the synchronization, the amount of motor units recruited, and the frequency of nervous stimulus, and not so much due to hypertrophy. The purpose of this research was to compare the maximal voluntary isometric force (MVIF), the electromyography activity (EMG) and the muscle thickness between pre-pubertal boys and girls. The results suggested that prepubescent children can increase strength following a strength training program that includes callisthenic exercises. There were no significant differences on the MVIF between boys and girls doing the triceps press exercise. The strength gains were not followed by an increase of muscle mass. In the same way, there were no significant differences according to gender on the thickness of the triceps of the both arm of the triceps. It seems that the elements underlying the increase and strength gains can be related to the increase of the coordination of the movement. The coordination seems to be an element that highly contributes to the increase of strength for more complex exercises.
- Comparison of a 10 week resistance strength training program, in muscle morphology, electromyography activity and strength gains on prepubescent girls and boysPublication . Monteiro, A.M.; Lopes, Vitor P.; Faro, AnaThe mechanisms that are behind the strength gains, in strength training programs, are not still well evidenced. It seems to exist the certainty that strength training produces greater gains, during puberty and after, in virtue, over all, of the increase of serum testosterone, which allows an increase of muscle hypertrophy. Strength gains gotten before puberty, will be resultant of neurological adaptations, such as, the improvement of inter and intra-muscle coordination and order, the synchronization, the amount of motor units recruited, and the frequency of nervous stimulus, and not so much due to hypertrophy. The purpose of this research was to compare the maximal voluntary isometric force (MVIF), the electromyography activity (EMG) and the muscle thickness between pre-pubertal boys and girls. The results suggested that prepubescent children can increase strength following a strength training program that includes callisthenic exercises. There were no significant differences on the MVIF between boys and girls doing the triceps press exercise. The strength gains were not followed by an increase of muscle mass. In the same way, there were no significant differences according to gender on the thickness of the triceps of the both arm of the triceps. It seems that the elements underlying the increase and strength gains can be related to the increase of the coordination of the movement. The coordination seems to be an element that highly contributes to the increase of strength for more complex exercises.
- Comparison of a 10 weeks resistance strength training program on prepubescent girls and boysPublication . Monteiro, A.M.; Faro, Ana; Lopes, Vitor P.; Barbosa, Tiago M.; Magalhães, PedroThe purpose of this study was to investigate the effects of a 10 weeks resistance training program on the development of the maximal isometric strength, muscle thickness, contracted brachial perimeters, relaxed brachial perimeters, the push-ups, the pull-ups and throwing a roller-skate hockey ball in prepusbescents girls and boy. The sample was divided into two different groups, the experimental one (EG, n =17) and the control one (CG, n = 17) and comprises 20 girls (9,44 ± 0,28 years) and 15 boys (9,34 ± 0,30 years) in the maturation stage I according to Tanner’s Scale. The EG group was submitted to a training program with callisthenic exercises three times a week (90 minutes each session) during 10 weeks. The program consisted of training push-ups, modified pull-ups and 2 exercises with elastics (elbows flexion and extension and extension of the arms above the head) until exhaustion. The training volume was gradually adapted from 3 series between the 1st and 3rd week to 4 series between the 4th and 6th week and to 5 series between 7th and 10th week. The maximal voluntary isometric force (MVIF) and the Electromyography signal (EMG) were acquired when the subjects made a single exercise of arm curl. To evaluate the MVIF was use a dynamometer (TSD121C from Biopac Systens Inc.). During the arm curl exercise, one surface electrode (TSD 150A from Biopac System Inc.) was attached in each biceps (MVIFARM). Ground electrode was attached to the elbow. The EMG signals were amplified by a differential amplifier with 2MW, a gain of 1000 and a bandwidth between 15-450Hz. The EMG signals were full-wave rectified and smoothed, allowing to determinate the integral of the EMG signal (iEMG) of right bicep (ARMR) and left bicep (ARML). The iEMG was relativizated according to the duration of the contraction. The muscle thicknesses of the biceps right arm (THICKBR) and left arm (THICKBL); the muscle thicknesses of triceps right arm (THICKTR) and left arm (THICKTL); the triceps skin folds of right arm (SKINTR) and left arm (SKINTL), were measured by B-mode ultrasonography, using real-time electronic scanner with 7.5MHz scanning head (Ecocamera Aloca SSD-500). The right relaxed brachial perimeters (RBPR) and left (RBPL) and the right contracted brachial perimeters (CBPR) and left (CBPL) were measured using the usual anthropometric procedures. We also evaluated the maximal number of push ups (PUSHUP) and modified pull ups (PULLUP) that each child was able to execute. Finally we measured the distance covered by the roller-skate hockey ball after being thrown (THRW). The change between the daily pay-test and after-test in such a way in boys as in girls was analyzed in both groups through the test of Wilcoxon. p≤0,05). Results: In the Wilcoxons’ test the following results had shown that the parameters with significant alterations were: in the male gender EG [(RBPR, p≤0,04; RBPL; p≤0,04; CBPR, p≤0,03; CBPL, p≤0,04; PUSHUP, p≤0,03; PULLUP, 0,03; THRW, p≤0,03)] in the CG [(RBPR, p≤0,71; RBPL; p≤0,74; CBPR, p≤0,89; CBPL, p≤0,58; PUSHUP, p≤0,83; PULLUP, 0,28; THRW, p≤0,50)] and the female EG [(RBPR, p≤0,01; RBPL; p≤0,04; CBPR, p≤0,00; CBPL, p≤0,01; PUSHUP, p≤0,00; PULLUP, 0,00; THRW, p≤0,02)] in the CG [(RBPR, p≤0,11; RBPL; p≤0,07; CBPR, p≤0,03; CBPL, p≤0,07; PUSHUP, p≤0,06; PULLUP, 0,78; THRW, p≤0,09)]. The results suggested that prepubescent children can increase strength following a strength training program that includes callisthenic exercises. This training program does not seem to have a significant effect in the development of the FIMV. The strength gains were not followed by an increase of muscle mass. In this study we only evaluated the neuromuscular factors (EMG) in FIMV and the alterations of the neuromuscular activations, were not significant. It seems that the elements underlying the increase and strength gains can be related to the increase of the coordination of the movement. The coordination seems to be an element that highly contributes to the increase of strength for more complex exercises.
- Comparison of a 10 weeks resistance strength training program on prepubescent girls and boysPublication . Monteiro, A.M.; Faro, Ana; Lopes, Vitor P.; Barbosa, Tiago M.; Magalhães, PedroThe mechanisms that are behind the strength gains, in strength training programs, are not still well evidenced. It seems to exist the certainty that strength training produces greater gains, during puberty and after, in virtue, over all, of the increase of serum testosterone, which allows an increase of muscle hypertrophy (Kraemer and Fleck 1993). Strength gains gotten before puberty, will be resultant of neurological adaptations, such as, the improvement of inter and intra-muscle coordination and order, the synchronization, the amount of motor units recruited, and the frequency of nervous stimulus, and not so much due to hypertrophy (Ramsay et al.,1990; Ozmun et al.,1993; Falk and Mor, 1996). The purpose of this study was to investigate the effects of a 10 weeks resistance training program on the development of the maximal isometric strength, muscle thickness, contracted brachial perimeters, relaxed brachial perimeters, the push-ups, the pull-ups and throwing a roller-skate hockey ball in prepusbescents girls and boy. Methods: The sample was divided into two different groups, the experimental one (EG, n =17) and the control one (CG, n = 17) and comprises 20 girls (9,44 ± 0,28 years) and 15 boys (9,34 ± 0,30 years) in the maturation stage I according to Tanner’s Scale. The EG group was submitted to a training program with callisthenic exercises three times a week (90 minutes each session) during 10 weeks. The program consisted of training push-ups, modified pull-ups and 2 exercises with elastics (elbows flexion and extension and extension of the arms above the head) until exhaustion. The training volume was gradually adapted from 3 series between the 1st and 3rd week to 4 series between the 4th and 6th week and to 5 series between 7th and 10th week. The maximal voluntary isometric force (MVIF) and the Electromyography signal (EMG) were acquired when the subjects made a single exercise of arm curl. To evaluate the MVIF was use a dynamometer (TSD121C from Biopac Systens Inc.). During the arm curl exercise, one surface electrode (TSD 150A from Biopac System Inc.) was attached in each biceps (MVIFARM). Ground electrode was attached to the elbow. The EMG signals were amplified by a differential amplifier with 2MW, a gain of 1000 and a bandwidth between 15-450Hz. The EMG signals were full-wave rectified and smoothed, allowing to determinate the integral of the EMG signal (iEMG) of right bicep (ARMR) and left bicep (ARML). The iEMG was relativizated according to the duration of the contraction. The muscle thicknesses of the biceps right arm (THICKBR) and left arm (THICKBL); the muscle thicknesses of triceps right arm (THICKTR) and left arm (THICKTL); the triceps skin folds of right arm (SKINTR) and left arm (SKINTL), were measured by B-mode ultrasonography, using real-time electronic scanner with 7.5MHz scanning head (Ecocamera Aloca SSD-500). The right relaxed brachial perimeters (RBPR) and left (RBPL) and the right contracted brachial perimeters (CBPR) and left (CBPL) were measured using the usual anthropometric procedures. We also evaluated the maximal number of push ups (PUSHUP) and modified pull ups (PULLUP) that each child was able to execute. Finally we measured the distance covered by the roller-skate hockey ball after being thrown (THRW). The change between the daily pay-test and after-test in such a way in boys as in girls was analyzed in both groups through the test of Wilcoxon. p≤0,05). Results: In the Wilcoxons’ test the following results had shown that the parameters with significant alterations were: in the male gender EG [(RBPR, p≤0,04; RBPL; p≤0,04; CBPR, p≤0,03; CBPL, p≤0,04; PUSHUP, p≤0,03; PULLUP, 0,03; THRW, p≤0,03)] in the CG [(RBPR, p≤0,71; RBPL; p≤0,74; CBPR, p≤0,89; CBPL, p≤0,58; PUSHUP, p≤0,83; PULLUP, 0,28; THRW, p≤0,50)] and the female EG [(RBPR, p≤0,01; RBPL; p≤0,04; CBPR, p≤0,00; CBPL, p≤0,01; PUSHUP, p≤0,00; PULLUP, 0,00; THRW, p≤0,02)] in the CG [(RBPR, p≤0,11; RBPL; p≤0,07; CBPR, p≤0,03; CBPL, p≤0,07; PUSHUP, p≤0,06; PULLUP, 0,78; THRW, p≤0,09)]. Discussion/Conclusion: The results suggested that prepubescent children can increase strength following a strength training program that includes callisthenic exercises. This training program does not seem to have a significant effect in the development of the FIMV. The strength gains were not followed by an increase of muscle mass. In this study we only evaluated the neuromuscular factors (EMG) in FIMV and the alterations of the neuromuscular activations, were not significant. It seems that the elements underlying the increase and strength gains can be related to the increase of the coordination of the movement. The coordination seems to be an element that highly contributes to the increase of strength for more complex exercises.
- O efeito de um programa de treino de força em raparigas e rapazes pré-púberesPublication . Monteiro, A.M.; Faro, Ana; Lopes, Vitor P.; Barbosa, Tiago M.Introdução e objectivos: Parece que os ganhos de força obtidos antes da puberdade serão resultantes de adaptações neuromusculares e não tanto devidos à hipertrofia. O objectivo deste estudo foi o de investigar os efeitos de um programa de treino de força-resistência durante 10 semanas, no desenvolvimento da Força Máxima Isométrica Voluntária (FMIV), nas alterações da espessura muscular e na actividade neuromuscular. Material e métodos: A amostra foi constituída pelo grupo experimental (GE, n =17) e o grupo de controlo (GC, n = 17), que compreendia 20 raparigas (9,44 ± 0,28 anos) e 15 rapazes (9,34 ± 0,30 anos), no estádio I de maturação sexual. O GE foi submetido a um programa de treino de exercícios calisténicos 3 PEDAGOGIA DO DESPORTO E DA EDUCAÇÃO FÍSICA Revista Portuguesa de Ciências do Desporto, 2004, vol. 4, nº 2 (suplemento) [171–193] 193 vezes por semana (90 minutos cada sessão), durante 10 semanas, consistindo em treinos de push-ups e pull-ups modificados e 2 exercícios com elásticos (flexão e extensão dos cotovelos e extensões dos braços acima da cabeça) até à exaustão. O volume foi gradualmente adaptado de 3 séries, entre a 1ª semana e a 3ª semana, para 4 séries entre a 4ª semana e a 6ª semana, para 5 séries entre a 7ª semana e a 10ª semana. A FMIV (dinamómetro TSD121C da Biopac Systems Inc) e o sinal electromiográfico (EMG) foram registados quando os sujeitos realizaram um único exercício de arm curl. Durante o arm curl foi colocado um eléctrodo de superfície (TSD 150A da Biopac System Inc.) em cada bícep (FMIVARM). O eléctrodo de terra estava preso ao olecrâneo direito. Os sinais EMG foram ampliados por um amplificador diferencial (impedância de entrada de 2 MW), um ganho de 1000 e com uma banda passante (entre os 15 e os 450Hz). Os sinais EMG foram rectificados e suavizados, permitindo determinar o integral do sinal de EMG (iEMG) em ambos os bíceps (ARMD e ARME). O iEMG foi relativizado de acordo com a duração da contracção. A espessura muscular de ambos os bíceps (ESPMBD e ESPMBE) e de ambos os triceps (ESPMTD e ESPMTE), e as pregas de ambos os tríceps (SKINTD e SKINTE), foram medidos pela ultrasonografia Bmode, (scanning head de 7.5MHz; Ecocamera Aloca SSD-500). Os perímetros braquiais relaxados (PBRD e PBRE) e braquiais contraídos (PBCD e PBCE) de ambos os bíceps foram também medidos (procedimentos antropométricos); avaliámos ainda o número máximo de push ups (PUSHUP) e pull-ups modificados (PULLUP) e a distância percorrida pela bola de hóquei (LANÇ). A alteração entre o pré-teste e o pós-teste, em ambos os sexos, foi analisada, em ambos os grupos, através do teste de Wilcoxon (p<=0,05). As alterações significantes foram: no GE masculino [(PBRD, p<=0,04; PBRE; p<= 0,04; PBCD, p<= 0,03; PBCE, p<= 0,04; PUSHUP, p<= 0,03; PULLUP, p<= 0,03; LANÇ, p<= 0,03)] e no GC [(PBRD, p<= 0,71; PBRE, p<= 0,74; PBCD, p<= 0,89; PBCE, p<= 0,58; PUSHUP, p<= 0,83; PULLUP, p<= 0,28; LANÇ, p<= 0,50)]; e no GE feminino: [(PBRD, p<= 0,01; PBRE; p<= 0,04; PBCD, p<= 0,00; PBCE, p<= 0,01; PUSHUP, p<= 0,00; PULLUP, p<= 0,00; LANÇ, p<= 0,02)] e no GC [(PBRD, p<= 0,11; PBRE; p<= 0,07; PBCD, p<= 0,03; PBCE, p<= 0,07; PUSHUP, p<= 0,06; PULLUP, p<= 0,78; LANÇ, p<= 0,09)]. Os pré-púberes podem aumentar a força, seguindo um programa de treino que inclua exercícios calisténicos. Este não aparenta ter efeitos significantes no desenvolvimento da FMIV. Os ganhos de força não foram acompanhados por um aumento da espessura muscular e nem da actividade neuromuscular. Parece que os elementos que sustentam os aumentos e ganhos de força podem ser relacionados ao aumento da coordenação do movimento.
- O efeito de um programa de treino de força em raparigas e rapazes pré-púberesPublication . Monteiro, A.M.; Faro, Ana; Lopes, Vitor P.; Barbosa, Tiago M.ntrodução e objectivos: Parece que os ganhos de força obtidos antes da puberdade serão resultantes de adaptações neuromusculares e não tanto devidos à hipertrofia. O objectivo deste estudo foi o de investigar os efeitos de um programa de treino de força-resistência durante 10 semanas, no desenvolvimento da Força Máxima Isométrica Voluntária (FMIV), nas alterações da espessura muscular e na actividade neuromuscular. Material e métodos: A amostra foi constituída pelo grupo experimental (GE, n =17) e o grupo de controlo (GC, n = 17), que compreendia 20 raparigas (9,44 ± 0,28 anos) e 15 rapazes (9,34 ± 0,30 anos), no estádio I de maturação sexual. O GE foi submetido a um programa de treino de exercícios calisténicos 3 PEDAGOGIA DO DESPORTO E DA EDUCAÇÃO FÍSICA Revista Portuguesa de Ciências do Desporto, 2004, vol. 4, nº 2 (suplemento) [171–193] 193 vezes por semana (90 minutos cada sessão), durante 10 semanas, consistindo em treinos de push-ups e pull-ups modificados e 2 exercícios com elásticos (flexão e extensão dos cotovelos e extensões dos braços acima da cabeça) até à exaustão. O volume foi gradualmente adaptado de 3 séries, entre a 1ª semana e a 3ª semana, para 4 séries entre a 4ª semana e a 6ª semana, para 5 séries entre a 7ª semana e a 10ª semana. A FMIV (dinamómetro TSD121C da Biopac Systems Inc) e o sinal electromiográfico (EMG) foram registados quando os sujeitos realizaram um único exercício de arm curl. Durante o arm curl foi colocado um eléctrodo de superfície (TSD 150A da Biopac System Inc.) em cada bícep (FMIVARM). O eléctrodo de terra estava preso ao olecrâneo direito. Os sinais EMG foram ampliados por um amplificador diferencial (impedância de entrada de 2 MW), um ganho de 1000 e com uma banda passante (entre os 15 e os 450Hz). Os sinais EMG foram rectificados e suavizados, permitindo determinar o integral do sinal de EMG (iEMG) em ambos os bíceps (ARMD e ARME). O iEMG foi relativizado de acordo com a duração da contracção. A espessura muscular de ambos os bíceps (ESPMBD e ESPMBE) e de ambos os triceps (ESPMTD e ESPMTE), e as pregas de ambos os tríceps (SKINTD e SKINTE), foram medidos pela ultrasonografia Bmode, (scanning head de 7.5MHz; Ecocamera Aloca SSD-500). Os perímetros braquiais relaxados (PBRD e PBRE) e braquiais contraídos (PBCD e PBCE) de ambos os bíceps foram também medidos (procedimentos antropométricos); avaliámos ainda o número máximo de push ups (PUSHUP) e pull-ups modificados (PULLUP) e a distância percorrida pela bola de hóquei (LANÇ). A alteração entre o pré-teste e o pós-teste, em ambos os sexos, foi analisada, em ambos os grupos, através do teste de Wilcoxon (p<=0,05). As alterações significantes foram: no GE masculino [(PBRD, p<=0,04; PBRE; p<= 0,04; PBCD, p<= 0,03; PBCE, p<= 0,04; PUSHUP, p<= 0,03; PULLUP, p<= 0,03; LANÇ, p<= 0,03)] e no GC [(PBRD, p<= 0,71; PBRE, p<= 0,74; PBCD, p<= 0,89; PBCE, p<= 0,58; PUSHUP, p<= 0,83; PULLUP, p<= 0,28; LANÇ, p<= 0,50)]; e no GE feminino: [(PBRD, p<= 0,01; PBRE; p<= 0,04; PBCD, p<= 0,00; PBCE, p<= 0,01; PUSHUP, p<= 0,00; PULLUP, p<= 0,00; LANÇ, p<= 0,02)] e no GC [(PBRD, p<= 0,11; PBRE; p<= 0,07; PBCD, p<= 0,03; PBCE, p<= 0,07; PUSHUP, p<= 0,06; PULLUP, p<= 0,78; LANÇ, p<= 0,09)]. Os pré-púberes podem aumentar a força, seguindo um programa de treino que inclua exercícios calisténicos. Este não aparenta ter efeitos significantes no desenvolvimento da FMIV. Os ganhos de força não foram acompanhados por um aumento da espessura muscular e nem da actividade neuromuscular. Parece que os elementos que sustentam os aumentos e ganhos de força podem ser relacionados ao aumento da coordenação do movimento.