Thesis (M.S.)--Brock University, 2004. / Includes bibliographical references (leaves 69-77).

Thesis (M.S.)--University of Memphis, 2002. / Includes bibliographical references (leaves 29-32).

The primary objective of the present study was to examine the effects of three resistance training programs that varied in either inter-set rest interval length or volume of training on the development of strength and muscle fiber size. Male subjects with a minimum of 1- year of regular resistance training experience were randomly assigned to one of three, 8- week training groups. The first set of all three programs was similar in that 10 repetitions to failure were performed. In program A (n=5) the load (78% 1-RM) remained constant for all subsequent sets. Program B (n=7) also used a constant load (80% 1-RM), however the rest interval was reduced from 3 minutes (as in Program A) to 1 minute. Subjects in this group performed additional sets to equate training volume with Program A. The training load for Program C (n=7) was progressively reduced (80% to 70% 1-RM) before each subsequent set to ensure the completion of 10 repetitions. Therefore, the volume performed was greater than that of Programs A and B. Single arm elbow flexion 1-RM increased by 12.3 +/- 3.5% in Program A, 16.5 +/-3.5% in Program B, and 14.1 +/- 4.7% in Program C. Gains in 10-RM equaled 16.3 +/-4.1%, 18.0 +/- 5.0% and 13.9 +/- 3.1% for Programs A, B and C, respectively. Although these increases in strength were significant (p<.05), there were no differences in the magnitude of change between the three groups. Increases in the cross-sectional area of type I and type II muscle fibers were similar after all three training programs. The second objective of this investigation was to measure the acute neuromuscular fatigue produced during a single session of each of the training protocols incorporated in the longitudinal part of this study. Force and IEMG during maximal isometric voluntary contractions (MVIC) along with blood lactate were assessed prior to and upon the completion of each protocol. Subjects performed 3 sets of single-arm elbow flexion to failure using a training load of approximately 77.3% 1-RM in Protocol A. During Protocol B, subjects utilized the same constant resistance but the rest-intervals between each set were 1 minute. Protocol C was designed to maintain the repetitions completed per set at 10 while utilizing 3-minute rest interval. During Protocol C, the load used during the first set was equal to that used during Protocol A and was then reduced by about approximately 5% for each of the two subsequent sets. Protocol A and Protocol B resulted in similar reductions in MVIC, whereas Protocol C (24.8 +/- 7.2%) resulted in a significantly (p<.05) greater reduction in MVIC than Protocol A (20.2 +/- 7.7%). Protocols A and B elicited similar reductions in the force-time curve of the MVIC. A significantly greater reduction in the final 300ms of the force-time curve was observed following Protocol C (in comparison to Protocol A) (p<.05). There were no significant changes in IEMG after subjects performed protocols A and B. A significant time effect (with no interaction effect) in IEMG was observed following the comparison of Protocol A with Protocol C. Blood lactate increased significantly in response to all three protocols with no differences between the protocols. The third objective of this study was to compare the magnitude of resistance training-induced acute fatigue before and after the completion of 8 weeks of resistance training specific to the fatigue protocols used. The magnitude of resistance training-induced acute neuromuscular fatigue remained unchanged following the resistance training programs. The results appear to indicate that acute neuromuscular fatigue produced during resistance training may not be associated with the chronic increases in muscle strength and size. / Graduate

Orientador: Fausto Bérzin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-21T07:47:29Z (GMT). No. of bitstreams: 1 Marques_CristhyanoPimenta_M.pdf: 1436980 bytes, checksum: e41a9812f77cbf93a7e9225b7fd352c6 (MD5) Previous issue date: 2012 / Resumo: O objetivo deste trabalho foi analisar a atividade eletromiográfica da parte descendente do músculo trapézio, submetidos à aplicação da acupuntura sistêmica nos pontos o LI4 (Hegu), LI11 (Quchi), ST36 (Zusanli), LR3 (Taichong), no repouso e durante a contração isométrica voluntária máxima (CIVM), antes e imediatamente após a aplicação da acupuntura. Amostra foi composta por 26 voluntários (10 do gênero masculino e 16 do gênero feminino) assintomáticos (obtido através de um questionário e exame físico) com idade entre 18 e 30 anos, divididos em três grupos: G1MS que recebeu acupuntura nos pontos o LI4 (Hegu), LI11 (Quchi), composta de 8 voluntários, G2MI recebeu acupuntura nos pontos ST36 (Zusanli), LR3 (Taichong), composta por 8 voluntários e o G3MSI que recebeu acupuntura nos pontos o LI4 (Hegu), LI11 (Quchi), ST36 (Zusanli ), LR3 (Taichong), com 10 voluntários. Este estudo foi aprovado pelo Comitê de Ética e Pesquisa (CEP) da Faculdade Atenas com protocolo 004/2011. A coleta de dados foi realizada utilizando-se eletrodo de superfície diferencial simples com ganho de 20 vezes e registrada através de um eletromiógrafo. O sinal eletromiográfico bruto foi quantificado pela Raiz Quadrada da Média (Root Mean Square - RMS) e a FMED (Frequência Mediana). Os sinais eletromiográficos foram submetidos a um filtro passa-alta de 20 Hz e passa-baixa de 500 Hz e a frequência de amostragem utilizada foi de 2000 Hz por canal. Os dados foram submetidos a análise estatística não paramétrica, empregando-se teste Wilcoxon. Comparando os valores médios de RMS bruto do músculo trapézio parte descendente foram observadas reduções significativas (p<0,05) entre situações de repouso para o trapézio parte descendente direito (TD) do G1MS e para o trapézio parte descendente esquerdo (TE) do G2MI, para a CIVM no trapézio parte descendente direito (TD) do G1MS. A FMED se mostrou significativa para o repouso do (TE) do G2MI apresentando -se aumentada e para a CIVM do (TE) como uma redução, não houve diferenças significativas (p>0,05) entre as demais variáveis estudadas. De acordo com a metodologia empregada e análise dos resultados deste estudo, conclui-se que a acupuntura sistêmica é capaz de provocar alterações da atividade eletromiográfica do músculo trapézio parte descendente na condição de repouso e CIMV para as combinações de pontos investigados neste estudo / Abstract: The objective of this study was to analyze the electromyographic activity of the descending part of the trapezius muscle undergoing systemic application of acupuncture points in the LI4 (Hegu), LI11 (Quchi), ST36 (Zusanli), LR3 (Taichong), at rest and during voluntary isometric contraction (MVIC) before and immediately after application of acupuncture. Sample consisted of 26 volunteers (10 males and 16 females) were asymptomatic (obtained through a questionnaire and physical examination) aged between 18 and 30 years, divided into three groups: G1MS the acupuncture points in the LI4 (Hegu), LI11 (Quchi), composed of eight volunteers, G2MI acupuncture points ST36 (Zusanli), LR3 (Taichong), composed of eight volunteers and G3MSI the acupuncture points in the LI4 (Hegu), LI11 (Quchi) ST36 (Zusanli), LR3 (Taichong), with 10 volunteers. This study was approved by the Ethics and Research (CER), School Athens Protocol 004/2011. Data collection was performed using a single differential surface electrode with a gain of 20 times and recorded by an electromyograph. The raw electromyographic signal was quantified by the Root Mean Square (Root Mean Square - RMS) and MF (median frequency). The signals were subjected to a high-pass filter of 20 Hz and low-pass and 500 Hz sampling frequency used was 2000 Hz per channel. The data were analyzed using nonparametric statistics, using the Wilcoxon test. Comparing the mean values of RMS rough descending part of the trapezius muscle were significant reductions (p <0.05) both at rest for the descending part of the right trapezius (TD) of G1MS and the descending part of the left trapezius (TE) of G2MI to the trapeze MVIC right descending part (TD) G1MS. The MF was significant for the home (TE) of G2MI presenting increased and the MVIC (TE) as a reduction, no significant differences (p> 0.05) among other variables. According to the methodology and analysis of the results of this study, it is concluded that acupuncture is capable of causing systemic changes electromyographic activity of the descending part of trapezius muscle at rest and CIMV for combinations of points investigated in this study / Mestrado / Anatomia / Mestre em Biologia Buco-Dental

The purpose of this study was to investigate the changes in cardiovascular dynamics as depicted by systolic time intervals, blood pressure and heart rate during a 50% MVC and 100% MVC isometric contraction of the forearm in a control and heated environment. Fourteen normal male volunteers aged 20 to 31 were used as subjects. Simultaneous recordings of the phonocardiogram, electrocardiogram, carotid pulse wave and blood pressure were conducted for each subject at rest and during exercise in a seated position. Subjects were tested, in room temperature and in a sauna where the skin temperature was raised to 40°C -41°C. Testing took place on two separate days with one day of rest in between. Half of the subjects experienced the heated conditions first, while the other half was tested in room conditions first. The results from two of the subjects were discarded because of poor quality reproduction of the time interval recordings. For each recording only the three clearest cycles closest to the termination of the contraction period were used for statistical analysis. The data were treated with a two-way ANOVA for each dependent variable. In some cases a post-hoc analysis (Newman-Keuls method) was used to determine specific differences between workload or environment effects. The fourteen dependent variables studied were divided into the following groups: a) Systole related variables left ventricular ejection time (LVET) mechanical systole (MS) total systole (TS) ejection time index (ETI) Diastole related variables cycle time (CT) diastole (DIAS) Sympathoadrenergic Activity (Contractility) pre-ejection period (PEP) isovolumetric contraction period (ICP) PEP/LVET (ratio) Afterload systolic blood pressure (BPs) diastolic blood pressure (BPd) Electromechanical Lag (EML) Heart Rate (HR) Myocardial Oxygen Consumption (Index) triple product (TRIP) -CONCLUSIONS The oxygen consumption of the myocardium as depicted by the triple product significantly increased during submaximal and maximal isometric handgrip contraction. This increase was evident at room temperature and during body heating. There was no significant change in the myocardial oxygen consumption as depicted by TRIP at rest or during isometric forearm contraction between the control and heated environments. This suggests that the heat stress did not significantly increase the myocardial oxygen requirements. 3. In a state of rest, increasing the skin temperature to between 40°C -41°C did not significantly alter either BPs or BPd when compared to a resting state at room temperature. However, BPs and BPd were substantially lower during isometric work in the heat than during isometric work at room temperature. 4. BPs and BPd significantly increased during 50% MVC and 100% MVC static contractions of the forearm. This increase was demonstrated in both environmental conditions. 5. All variables depicting changes in left ventricular systole (LVET; MS; TS) and ventricular diastole (diastole and CT) were found to become significantly reduced with submaximal and maximal static contractions of the forearm. These changes were evident in both environments. 6. A strong inverse correlation was found between HR and LVET, CT and diastole. HR significantly increased from rest to 100% MVC in both environmental conditions. Consequently, it is suggested that alterations in LVET, CT and diastole are largely determined by the rate of myocardial contraction. 7. The ejection time index significantly increased in both environmental conditions with a 50% MVC and 100% MVC static contraction of the forearm. The electromechanical lag showed a general tendency to decrease during an isometric handgrip contraction. However, subsequent post-hoc analysis (Newman-Keuls) demonstrated that EML did not significantly decrease during a submaximal or maximal isometric contraction of the forearm. It is suggested that care be taken to choose a proper statistical procedure for analysis of EML. The contractility of the heart as depicted by changes in LCP, PEP and PEP/LVET increases in response to a pressure load produced by static exertion but is not significantly altered by an augmented volume load associated with heat stress. HR, LVET, MS, TS, PEP, ICP, PEP/LVET and EML changed in an additive fashion from rest to 100% MVC during subjection to a volume load and pressure load simultaneously. In contrast alterations in BPs, BPd, ETI, CT, diastole, and TRIP displayed interactive characteristics during the same test conditions . / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

No description available.

The purpose of this investigation is to propose a method for determining resultant joint moments from a Biodex System 3 isokinetic dynamometer. Previous investigations using a dynamometers determined that measured moments from a dynamometer do not equate to the moment applied by the joint. Using Biodex System 3 dimensions and equipment, the proposed method corrects for gravity, acceleration and inertia moments, and relative angular movement between the dynamometer and the joint axis of rotation for the knee and ankle. The current method includes gravitations correction using a 3rd order polyfit method to a 4°/s passive trial, and inclusion of inertial moments from the dynamometer arm and limb segment. A method is also proposed to correct for gravitational moments, acceleration and inertia moments, and distal joint moments while testing the hip. Previously proposed methods are then compared to the proposed method in isometric and isokinetic exertions. The comparison to a known moment concluded that the results for the isometric exertion are accurate for the proposed method. If the torque measurements from the dynamometer are independent of the velocity, as reported by the manufacturer, the validation of the proposed method for isometric testing holds true for isokinetic as well. The results from isokinetic testing show reasonable results for determining the resultant joint moments. The proposed method can be simplified for clinical or experimental testing. If inertial and acceleration moments are not of concern, than using the propsed gravitational correction will account for the COM (Center of Mass). No additional measurements of the limb segement and dynamometer attachment are needed. The proposed method is recommended for Biodex System 3 isokinetic dynamometer correction in obtaining resultant joint moments at the knee, ankle, and hip. / Master of Science

The effective prescription of resistance exercise for strength and power development has been a source of debate amongst practitioners and sport scientist alike. One of the key issues in this area relates to the training load that would best facilitate strength and power adaptation. Heavy loads (>60-70% 1RM) have been traditionally used for maximal strength development by facilitating changes in neural function (strength) and muscle size (hypertrophy). However, many studies have now found lighter load (>45%1RM) training equally effective in improving both strength and hypertrophy. Similarly, many studies have found heavy load training effective in enhancing various measures of power though lighter loads (e.g. 45% 1RM) are thought to maximise the mechanical power output of muscle. Realising that adaptation depends upon some interaction between the mechanical, hormonal and metabolic stimuli, examining these responses would enhance our understanding of the underlying determinants of strength and power, and thereby improve strength and conditioning practice. Therefore, the purpose of this study was to examine the mechanical, hormonal and metabolic responses to equal volume light and heavy loading schemes. Eleven males (mean 26.6 ± 6.7 years; mean 79.0 ± 8.1 kg) with a minimum of 12 months weight training experience each performed two exercises (Smith squat and supine squat) at a light (45% 1RM) and heavy (88% 1RM) intensity. The light scheme consisted of eight sets of six repetitions, with six sets of four repetitions performed in the heavy scheme. Rest periods of three and four minutes respectively were used. Saliva sampling was used to determine the hormonal (cortisol and testosterone) and metabolic (lactate) responses. Samples were collected at rest (pre-), immediately after the first exercise (mid-), at the conclusion of the second exercise (P0) and every 15 minutes thereafter for one hour (P15, P30, P45, P60). Mean values for all variables were analysed with a paired sample T-test. Chances that the true effects were substantial (% and qualitative) were also calculated. No significant (P>0.05) difference in total forces was found between schemes; however, the light scheme produced significantly greater total time under tension (36%), total work (37%) and total power output (115%). Total impulse (38%) was the only variable found to be greater in the heavy scheme. A decrease in testosterone (TST) was observed in the heavy scheme (-4 to -29%) with no significant changes found across the light scheme (1 to 12%). Cortisol decreased in the light (-6 to -30%) and heavy (-14 to -44%) schemes until P45. An increase in the TST/cortisol ratio was observed in both the light (17 to 49%) and heavy (2 to 44%) schemes. Both loading schemes resulted in similar increases in lactate (0.3 to 1.0nmol/l). Equating two schemes by volume resulted in differential responses, many of which favoured the lighter scheme in terms of mechanical, hormonal and metabolic outputs. These findings suggest that load or intensity employed may be not as important as initially proposed and that other factors (e.g. volume, technique) may explain the similar strength and hypertrophy adaptation reported in studies comparing light and heavy schemes.

Thesis (M App Sc) -- University of South Australia, 1992

The effective prescription of resistance exercise for strength and power development has been a source of debate amongst practitioners and sport scientist alike. One of the key issues in this area relates to the training load that would best facilitate strength and power adaptation. Heavy loads (>60-70% 1RM) have been traditionally used for maximal strength development by facilitating changes in neural function (strength) and muscle size (hypertrophy). However, many studies have now found lighter load (>45%1RM) training equally effective in improving both strength and hypertrophy. Similarly, many studies have found heavy load training effective in enhancing various measures of power though lighter loads (e.g. 45% 1RM) are thought to maximise the mechanical power output of muscle. Realising that adaptation depends upon some interaction between the mechanical, hormonal and metabolic stimuli, examining these responses would enhance our understanding of the underlying determinants of strength and power, and thereby improve strength and conditioning practice. Therefore, the purpose of this study was to examine the mechanical, hormonal and metabolic responses to equal volume light and heavy loading schemes. Eleven males (mean 26.6 ± 6.7 years; mean 79.0 ± 8.1 kg) with a minimum of 12 months weight training experience each performed two exercises (Smith squat and supine squat) at a light (45% 1RM) and heavy (88% 1RM) intensity. The light scheme consisted of eight sets of six repetitions, with six sets of four repetitions performed in the heavy scheme. Rest periods of three and four minutes respectively were used. Saliva sampling was used to determine the hormonal (cortisol and testosterone) and metabolic (lactate) responses. Samples were collected at rest (pre-), immediately after the first exercise (mid-), at the conclusion of the second exercise (P0) and every 15 minutes thereafter for one hour (P15, P30, P45, P60). Mean values for all variables were analysed with a paired sample T-test. Chances that the true effects were substantial (% and qualitative) were also calculated. No significant (P>0.05) difference in total forces was found between schemes; however, the light scheme produced significantly greater total time under tension (36%), total work (37%) and total power output (115%). Total impulse (38%) was the only variable found to be greater in the heavy scheme. A decrease in testosterone (TST) was observed in the heavy scheme (-4 to -29%) with no significant changes found across the light scheme (1 to 12%). Cortisol decreased in the light (-6 to -30%) and heavy (-14 to -44%) schemes until P45. An increase in the TST/cortisol ratio was observed in both the light (17 to 49%) and heavy (2 to 44%) schemes. Both loading schemes resulted in similar increases in lactate (0.3 to 1.0nmol/l). Equating two schemes by volume resulted in differential responses, many of which favoured the lighter scheme in terms of mechanical, hormonal and metabolic outputs. These findings suggest that load or intensity employed may be not as important as initially proposed and that other factors (e.g. volume, technique) may explain the similar strength and hypertrophy adaptation reported in studies comparing light and heavy schemes.