High intensity cycle ergometer exercise tests are designed to measure power outputs. Most of the tests utilise resistive forces that are based on total-body mass values (TBM). Conceptually, selecting an optimal resistive force based on total-body mass may not be the best approach. Resistive forces that reflect the mass of the lean tissue specifically involved in the performance of the diagnostic task may be more appropriate. To investigate this theory the following studies were proposed. STUDY ONE. To identify the upper body contribution to a cycle ergometer test via the handgrip. STUDY TWO. To examine any differences in power profiles, when loading procedures were based on total-body mass (TBM) or fat-free mass (FFM). STUDY THREE. To investigate the sympathoadrenergic and blood lactate responses, when loading procedures were based on total-bodymass (TBM) or fat-free mass (FFM).STUDY FOUR. To measure blood concentrations of, lipidhydroperoxides (LH), malondialdehyde (MDA), creatine kinase (CK)and myoglobin (Mb) that may occur when resistive forces were based on total-body mass (TBM) or fat-free mass (FFM). STUDY ONEIndices of mechanical power output were obtained from twelve subjects during high intensity leg cycle ergometry tests (20 second duration; 75 grams per kilogram total-body mass) using two protocols:one with a standard handle-bar grip (with - grip), and one with supinated wrists (without - grip). Peak mechanical power, mean mechanical power, fatigue index and total mechanical work values were calculated for each subject during each test, and the sample mean differences associated with the two protocols were compared using paired Student t-tests. The with-grip protocol yielded significantly greater peak mechanical power output and greater fatigue index than the without - grip protocol(886 ± 124 W vs 815 ± 151 W, respectively; and 35 ± 10% vs 25 ±8%, respectively ; P < 0.05}. The electrical activity of the anterior forearm musculature was measured in the twelfth subject during the performance of each of the test protocol in an initial attempt to quantify any differences in muscular activity between protocols. While peak mechanical power output was greater during the with - grip protocol,than during the without - grip protocol, the electromyographs showed much greater forearm muscle activity during the with - grip protocol. Thus the protocol which allowed for the greatest measure of peak leg power output was also associated with considerable arm muscle activity. These findings should be considered when blood samples are taken from the arm for the biochemical analysis of cycling tasks. STUDY TWOStudy two compared the maximal exercise performance of 10 men during friction braked cycle ergometry of 20 s duration when resistive forces reflected total-body mass (TBM) or fat-free mass (FFM). Fat mass was calculated from the sum of skinfold thicknesses. Increases(P < 0.05) in peak power output (PPO) were found between TBM and FFM (1015 ± 165 W TBM vs 1099 ± 172 W FFM). Decreases (P <0.05) were observed for the time taken to reach PPO (3.8 ± 1.4 s TBMvs 2.9 ± 1 s FFM). Pedal velocity increased (P < 0.05) during the FFM protocol (129.4 ± 8.2 rpm TBM vs 136.3 ± SrpmFFM). Rating of perceived exertion (RPE) was also (P < 0.05) greater for FFM (18.4 ± 1.6 TBM vs 19.8 ± 0.4 FFM). No changes were found for Mean Power Output (MPO), fatigue index (FI) or Work Done(WD) between trials. These findings suggest that high intensity resistive force loading protocols may need to be reconsidered. Results from this study indicate that the active tissue component of body composition needs consideration in resistive force selection when ascertaining maximal cycle ergometer power profiles. STUDY THREEThe purpose of study three was to compare the sympathoadrenergic and blood lactate responses to maximal exercise performance during 30s cycle ergometry when resistive forces were dependent on total-bodymass (TBM) and fat-free mass (FFM). Correlations (P < 0.05) were recorded between PPOs, and immediate post-exercise noradrenaline concentrations for both the TBM and FFM protocols. Increases (P < 0.05) in the concentrations of adrenaline, noradrenaline and lactate from rest to immediately post exercise were observed for both the TBM and FFM protocols, with decreases in concentration noted (P < 0.05) immediately post to 24 h post exercise (see table 6.3). There were no differences (P > 0.05) recorded between TBM and FFM during any of the blood sampling stages. These results are interesting when we consider that with increases in PPO recorded for the FFM protocol there were no differences between protocols in the estimation of neurophysiological and metabolic stress as determined by plasmaadrenaline, noradrenaline and blood lactate concentrations. STUDY FOUR. Study four compared power outputs, and blood levels of, lipidhydroperoxides (LH), malondialdehyde (MDA), creatine kinase (CK), myoglobin (Mb) and lactate ([La-]g) following 30 s of maximal cycleergometry exercise when resistive forces were dependent on total-bodymass (TBM) or fat-free mass (FFM). Alpha-tocopherol, Retinol and uric acid concentrations were also measured to quantify the activity of selected antioxidants. Cardiac troponin concentrations (cTnl) were also determined to exclude protein leakage from the myocardium. Increases in CK activity was recorded from rest to immediately post exercise during both the TBM and FFM protocols (P < 0.05 ; P < 0.05 respectively) and decreased from immediately post to 24 h post exercise during the FFM protocol only. LH increased from rest to immediately post exercise for both the TBM and FFM protocol (P < 0.05 ; P < 0.05 respectively) and decreased 24 h post exercise for both protocols. Differences in LH concentrations were also observed immediately post exercise between the TBM and FFM protocols (P < 0.05). Increases in MDA concentrations were recorded from rest to immediately post exercise for TBM (P < 0.05), with a decrease recorded from immediate post to 24 h post exercise. Differences in MDA concentrations were recorded between the TBM and FFM protocol immediately post exercise. Differences in TBM and FFM concentrations were also recorded immediately post exercise for Mb (P < 0.05). Blood lactate values([La~]B) increased (P < 0.05) from rest, to immediately post exercise,and returned to resting values 24 h post exercise for both the TBM and FFM. Alpha-tocopherol and uric acid concentrations decreased from rest to immediately post exercise for both TBM and FFM protocols (P < 0.05 ; P < 0.05 respectively) and increased 24 h post exercise. There were no changes observed in Retinol concentrations for any of the blood sampling stages. The results of the study suggest that greater power outputs are obtainable with significantly less muscle damage and oxidative stress when resistive forces reflect FFM mass during loading procedures. This finding may also be related to better force velocity relationships observed for the FFM protocol, ie more efficient mechanics of movement which may result in less strain, and therefore less internal damage. Findings from the study indicate that procedures that produce greater power values, with no difference in stress response, that are less damaging to muscle tissue and relate to the active tissue during this type of exercise, may need to be explored in preference to loading procedures that include both lean and fat masses.

München, Techn. Univ., Diss., 2000.

BACKGROUND: Maximal oxygen uptake (VO2max) is an important predictor for cardiovascular health. VO2max is often calculated using submaximal tests in clinic. Ekblom-Bak (EB-test) test is a new submaximal cycle ergometer test for calculating VO2max based on differences in heart frequency between two different workloads. OBJECTIVES: The aim of the study was to examine the correlation and agreement between the two methods for calculating VO2max; Åstrand cycle test (Å-test) and EB-test. A secondary aim was also to examine VO2max of physiotherapy students in Uppsala. METHODS: The study design was descriptive and comparative. 30 subjects aged 20-30 were recruited by convenience sampling. Both tests were performed during the same session. Agreement and correlation between the two tests was calculated through paired t-tests and Pearson’s correlation coefficients respectively. RESULTS: Calculated VO2max for the subjects was on average 3.65 L/min, 52.03 ml/kg/min (EB-test) and 3.38 L/min, 47.97 ml/kg/min (Å-test). The differences between the two tests were statistically significant for both L/min (p = 0.01) and ml/kg/min (p = 0.009). The correlation between the two tests was r = 0.76 (L/min) and r = 0.59 (ml/kg/min) respectively. CONCLUSION: This study shows a statistically significant difference between the two submaximal cycle ergometer tests for calculating VO2max. The difference between the two tests is clinically significant and should be considered upon use. Both tests should be used consistently upon evaluating different treatments. Further research in the area is needed.

Considerando que a maioria das clínicas de reabilitação física possui um ciclo ergômetro de uso restrito a membros inferiores, e que o ciclo ergômetro para membros superiores é ainda pouco comercializado e de alto custo, longe do alcance de muitos profissionais envolvidos na reabilitação em nosso país, avaliou-se a necessidade de desenvolver um equipamento que suprisse ambas necessidades. No presente estudo, um aparelho relativamente simples e de baixo custo, capaz de proporcionar meios para o exercício rotativo dos membros superiores e inferiores simultaneamente, foi projetado e construído com materiais de fácil obtenção e preço acessível. O ciclo ergômetro foi confeccionado e calibrado após a adaptação de um torquímetro, onde as medidas foram registradas por um sistema para medição de torque em eixos rotativos por meio de telemetria. Foram realizadas a calibração estática e avaliação dinâmica dos pedais e manípulos, onde os resultados demonstraram que o equipamento desenvolvido é capaz de realizar movimentos independentes de rotação dos membros inferiores ou superiores, isoladamente ou de forma conjunta, permitindo potencializar e ampliar o leque de benefícios gerados pelos aparelhos isolados. Este equipamento poderá ser útil na reabilitação de pacientes com patologias diversas como também para a realização de testes de esforços físicos nos departamentos de reabilitação e academias de ginástica / Considering that most of the physical rehabilitation clinics has a cycle ergometer which use is restrict to the lower limbs and that the cycle ergometer for upper limbs is still a little commercialized and high cost, out of the possibilities of many professionals involved in rehabilitation in our country, it was evaluated the necessity of developing equipment that supplied both necessities. In the present study, a relatively simple and low cost device able to provide ways to the rotatory exercise of both upper and lower limbs simultaneously was projected and constructed with easily obtained accessible price materials. The cycle ergometer was built and gauged after the adaptation of a torquimeter, where the measures were recorded by a rotatory axis torque measure system through telemetry. It was accomplished a static and dynamic calibration on pedals and handles, which results showed that the developed equipment is able to accomplish independent rotation movements for both upper and lower limbs, isolately or entirely, allowing to pontentialize and amplify the list of benefits generated by the isolate devices. This equipment may be useful to rehabilitate patients bearing diverse pathologies as well as to the accomplishment of physical effort tests in rehabilitation departments and gyms

Laboratory-based rowing tests are the established standard for assessing fitness traits among elite rowers, and for prescribing individualised exercise intensities for training. But because tests occur on a rowing ergometer, the specificity of laboratory testing has been questioned compared with the criterion of on-water rowing. This project validated equipment required to replicate a laboratory-based rowing test in the field and evaluated the feasibility of on-water tests. Ergometer and on-water test results were compared to assess the validity of ergometer-derived training prescriptions and to establish the effectiveness of on-water tests for monitoring longitudinal fitness changes and for predicting rowing performance. Concept2 rowing ergometers (Morrisville, USA) have frequently been used for rowing tests. Although subtle design variations exist between the different models of Concept2 ergometer, there were no substantial differences between the results from incremental rowing tests using Model C and Model D ergometers. The Concept2 Model D was therefore accepted as the standard ergometer for subsequent laboratory tests. Typical error (TE) results from duplicate Concept2 Model D tests conducted 2-4 d apart showed that laboratory tests were highly reliable (TE: maximal power = 2.8%, peak oxygen consumption = 2.5%). As oxygen consumption (VO2) is measured routinely during laboratory rowing tests, it is necessary to obtain similar measurements during any on-water protocol. The MetaMax 3B portable indirect calorimetry system (Cortex, Leipzig, Germany) was therefore validated against a first-principles, laboratory-based indirect calorimetry system (MOUSe, Australian Institute of Sport, Canberra, Australia). VO2 from the MetaMax was significantly higher during submaximal exercise (p=0.03), although results were within 0.16 L.min-1 (4.1%) across all exercise intensities. There was good agreement between duplicate MetaMax trials separated by ~2 d; mean VO2 was within 0.11 L.min-1 (2.5%) and TE was ¡Ü2.3%. The specificity of rowing testing was improved using an On-water incremental test that replicated a laboratory-based Ergometer protocol. However, the individual variation in physiological responses between-tests meant that training intensity recommendations from the Ergometer test were not always applicable to on-water training. Furthermore, measurements from the On-water protocol displayed similar or lesser reliability (TE=1.9-19.2%) compared with the Ergometer test (TE=0.1-11.0%). As an effective fitness test must also be sensitive to longitudinal changes, the responses to 6 wks training were compared between the Ergometer and On-water methods. The magnitude of On-water training effects were usually greater (small Cohen¡¯s effect size) compared with the Ergometer test (trivial effect), although On-water and Ergometer tests both indicated that training responses were negligible because virtually all changes were less than one of their respective TEs. Correlations between test results and rowing performance were largest when rowing mode was matched between conditions, but Ergometer results provided the highest correlations (Ergometer vs. 2000-m ergometer time-trial: R= -0.92 to -0.97 compared with On-water vs. On-water maximal power output: R=0.52 to 0.92). Although On-water tests improved the specificity of on-water training prescriptions, these tests provided no obvious benefits for monitoring longitudinal fitness changes or performance compared with Ergometer tests. Given that On-water tests are also more time consuming and logistically challenging, their practical application is limited.

O objetivo deste estudo foi verificar se a mudança no posicionamento das pedaleiras da posição padrão chamada de posição usual para uma posição 10 cm superior a esta (sem alteração do ângulo 45º) chamada de posição modificada, interfere nas variáveis dependentes das relações entre força X tempo (potência e impulso). Como objetivos específicos pretendem-se avaliar as forças externas nos membros superiores e inferiores durante testes no remo ergômetro, relacionar os impulsos encontrados na manopla e nas pedaleiras à mudança do posicionamento das pedaleiras e verificar em qual posição das pedaleiras os remadores atingem a potência máxima. Foram construídas duas plataformas de força para mensuração das forças (perpendicular e paralela) aplicadas nas pedaleiras do remo ergômetro. Foi medida também a força exercida na manopla do remo ergômetro, sendo os testes filmados para obtenção das informações cinemáticas. O protocolo consistiu em remar durante 1 min nas potências nominais de 100, 200, 300, 400 watts e máxima subjetiva de cada atleta. O protocolo foi repetido para cada uma das posições das pedaleiras, com a ordem de execução aleatorizada. Foram calculadas curvas médias de força representativas de cada situação e os impulsos da manopla e pedaleiras. Dos oito atletas avaliados cinco atingiram maiores valores de potência máxima na posição modificada, um atleta obteve menores valores nessa posição, e outros dois não tiveram diferenças entre os posicionamentos. Para a fase de propulsão o impulso na direção horizontal, apresentou diferença apenas quando positivo, e nas potências 100 e 200 W, favorável na posição usual. O impulso na direção vertical diferiu, quando negativo, nas potências de 100, 300, 400 e máx, favorável na posição modificada. Considerando a falta de tempo de ambientação dos remadores a nova posição, pode-se inferir que a posição modificada foi melhor, e testes envolvendo modificações no barco são indicados para uma avaliação mais definitiva. / The objective of this study was to verify if the change in the positioning footstrechers in the standard position to 10 centimeters above called modified position interfere with the dependent variable of the relations between force X time (power and impulse). As objective specific it is intended to evaluate the external forces in the superior and inferior limbs during tests in the rowing ergometer, to relate the impulses found in handle and in the footstrechers to the change of the positioning of the footstrechers and to verify which position of the footstrechers the rowers reach the maximum power. Two platforms of force were to construct for measure of the forces (perpendicular and parallel) applied in the footstrechers of the rowing ergometer. The force exerted in handle was also measured, being the tests filmed for attainment of the kinematic information. The protocol consisted of rowing during 1 min in the normal rated powers of 100, 200, 300, 400 watts and subjective maximal of each athlete. The protocol was repeated for each one of the positions of the footstrechers, with the randomized order. An average curve of force of each situation was to calculate representative and the impulses of handle and footstrechers. Of eight evaluated athletes five they had reached greater values of maximum power in the modified position, only one athlete showed smaller values in the modified position, and others two had not differences between the positioning. For the propulsive phase the impulse in the horizontal direction showed only difference when positive, and in the powers 100 and 200 W, favorable in the standard position. The impulse in the vertical direction differed, when negative, in the powers of 100, 300, 400 and max, favorable in the modified position. Considering the lack of time of environment of the rowers the new position, it can be inferred that the modified position was better, and tests involving modifications in the boat are indicated for a more definitive evaluation.

O objetivo deste estudo foi verificar se a mudança no posicionamento das pedaleiras da posição padrão chamada de posição usual para uma posição 10 cm superior a esta (sem alteração do ângulo 45º) chamada de posição modificada, interfere nas variáveis dependentes das relações entre força X tempo (potência e impulso). Como objetivos específicos pretendem-se avaliar as forças externas nos membros superiores e inferiores durante testes no remo ergômetro, relacionar os impulsos encontrados na manopla e nas pedaleiras à mudança do posicionamento das pedaleiras e verificar em qual posição das pedaleiras os remadores atingem a potência máxima. Foram construídas duas plataformas de força para mensuração das forças (perpendicular e paralela) aplicadas nas pedaleiras do remo ergômetro. Foi medida também a força exercida na manopla do remo ergômetro, sendo os testes filmados para obtenção das informações cinemáticas. O protocolo consistiu em remar durante 1 min nas potências nominais de 100, 200, 300, 400 watts e máxima subjetiva de cada atleta. O protocolo foi repetido para cada uma das posições das pedaleiras, com a ordem de execução aleatorizada. Foram calculadas curvas médias de força representativas de cada situação e os impulsos da manopla e pedaleiras. Dos oito atletas avaliados cinco atingiram maiores valores de potência máxima na posição modificada, um atleta obteve menores valores nessa posição, e outros dois não tiveram diferenças entre os posicionamentos. Para a fase de propulsão o impulso na direção horizontal, apresentou diferença apenas quando positivo, e nas potências 100 e 200 W, favorável na posição usual. O impulso na direção vertical diferiu, quando negativo, nas potências de 100, 300, 400 e máx, favorável na posição modificada. Considerando a falta de tempo de ambientação dos remadores a nova posição, pode-se inferir que a posição modificada foi melhor, e testes envolvendo modificações no barco são indicados para uma avaliação mais definitiva. / The objective of this study was to verify if the change in the positioning footstrechers in the standard position to 10 centimeters above called modified position interfere with the dependent variable of the relations between force X time (power and impulse). As objective specific it is intended to evaluate the external forces in the superior and inferior limbs during tests in the rowing ergometer, to relate the impulses found in handle and in the footstrechers to the change of the positioning of the footstrechers and to verify which position of the footstrechers the rowers reach the maximum power. Two platforms of force were to construct for measure of the forces (perpendicular and parallel) applied in the footstrechers of the rowing ergometer. The force exerted in handle was also measured, being the tests filmed for attainment of the kinematic information. The protocol consisted of rowing during 1 min in the normal rated powers of 100, 200, 300, 400 watts and subjective maximal of each athlete. The protocol was repeated for each one of the positions of the footstrechers, with the randomized order. An average curve of force of each situation was to calculate representative and the impulses of handle and footstrechers. Of eight evaluated athletes five they had reached greater values of maximum power in the modified position, only one athlete showed smaller values in the modified position, and others two had not differences between the positioning. For the propulsive phase the impulse in the horizontal direction showed only difference when positive, and in the powers 100 and 200 W, favorable in the standard position. The impulse in the vertical direction differed, when negative, in the powers of 100, 300, 400 and max, favorable in the modified position. Considering the lack of time of environment of the rowers the new position, it can be inferred that the modified position was better, and tests involving modifications in the boat are indicated for a more definitive evaluation.

O objetivo deste estudo foi verificar se a mudança no posicionamento das pedaleiras da posição padrão chamada de posição usual para uma posição 10 cm superior a esta (sem alteração do ângulo 45º) chamada de posição modificada, interfere nas variáveis dependentes das relações entre força X tempo (potência e impulso). Como objetivos específicos pretendem-se avaliar as forças externas nos membros superiores e inferiores durante testes no remo ergômetro, relacionar os impulsos encontrados na manopla e nas pedaleiras à mudança do posicionamento das pedaleiras e verificar em qual posição das pedaleiras os remadores atingem a potência máxima. Foram construídas duas plataformas de força para mensuração das forças (perpendicular e paralela) aplicadas nas pedaleiras do remo ergômetro. Foi medida também a força exercida na manopla do remo ergômetro, sendo os testes filmados para obtenção das informações cinemáticas. O protocolo consistiu em remar durante 1 min nas potências nominais de 100, 200, 300, 400 watts e máxima subjetiva de cada atleta. O protocolo foi repetido para cada uma das posições das pedaleiras, com a ordem de execução aleatorizada. Foram calculadas curvas médias de força representativas de cada situação e os impulsos da manopla e pedaleiras. Dos oito atletas avaliados cinco atingiram maiores valores de potência máxima na posição modificada, um atleta obteve menores valores nessa posição, e outros dois não tiveram diferenças entre os posicionamentos. Para a fase de propulsão o impulso na direção horizontal, apresentou diferença apenas quando positivo, e nas potências 100 e 200 W, favorável na posição usual. O impulso na direção vertical diferiu, quando negativo, nas potências de 100, 300, 400 e máx, favorável na posição modificada. Considerando a falta de tempo de ambientação dos remadores a nova posição, pode-se inferir que a posição modificada foi melhor, e testes envolvendo modificações no barco são indicados para uma avaliação mais definitiva. / The objective of this study was to verify if the change in the positioning footstrechers in the standard position to 10 centimeters above called modified position interfere with the dependent variable of the relations between force X time (power and impulse). As objective specific it is intended to evaluate the external forces in the superior and inferior limbs during tests in the rowing ergometer, to relate the impulses found in handle and in the footstrechers to the change of the positioning of the footstrechers and to verify which position of the footstrechers the rowers reach the maximum power. Two platforms of force were to construct for measure of the forces (perpendicular and parallel) applied in the footstrechers of the rowing ergometer. The force exerted in handle was also measured, being the tests filmed for attainment of the kinematic information. The protocol consisted of rowing during 1 min in the normal rated powers of 100, 200, 300, 400 watts and subjective maximal of each athlete. The protocol was repeated for each one of the positions of the footstrechers, with the randomized order. An average curve of force of each situation was to calculate representative and the impulses of handle and footstrechers. Of eight evaluated athletes five they had reached greater values of maximum power in the modified position, only one athlete showed smaller values in the modified position, and others two had not differences between the positioning. For the propulsive phase the impulse in the horizontal direction showed only difference when positive, and in the powers 100 and 200 W, favorable in the standard position. The impulse in the vertical direction differed, when negative, in the powers of 100, 300, 400 and max, favorable in the modified position. Considering the lack of time of environment of the rowers the new position, it can be inferred that the modified position was better, and tests involving modifications in the boat are indicated for a more definitive evaluation.

Considerando que a maioria das clínicas de reabilitação física possui um ciclo ergômetro de uso restrito a membros inferiores, e que o ciclo ergômetro para membros superiores é ainda pouco comercializado e de alto custo, longe do alcance de muitos profissionais envolvidos na reabilitação em nosso país, avaliou-se a necessidade de desenvolver um equipamento que suprisse ambas necessidades. No presente estudo, um aparelho relativamente simples e de baixo custo, capaz de proporcionar meios para o exercício rotativo dos membros superiores e inferiores simultaneamente, foi projetado e construído com materiais de fácil obtenção e preço acessível. O ciclo ergômetro foi confeccionado e calibrado após a adaptação de um torquímetro, onde as medidas foram registradas por um sistema para medição de torque em eixos rotativos por meio de telemetria. Foram realizadas a calibração estática e avaliação dinâmica dos pedais e manípulos, onde os resultados demonstraram que o equipamento desenvolvido é capaz de realizar movimentos independentes de rotação dos membros inferiores ou superiores, isoladamente ou de forma conjunta, permitindo potencializar e ampliar o leque de benefícios gerados pelos aparelhos isolados. Este equipamento poderá ser útil na reabilitação de pacientes com patologias diversas como também para a realização de testes de esforços físicos nos departamentos de reabilitação e academias de ginástica / Considering that most of the physical rehabilitation clinics has a cycle ergometer which use is restrict to the lower limbs and that the cycle ergometer for upper limbs is still a little commercialized and high cost, out of the possibilities of many professionals involved in rehabilitation in our country, it was evaluated the necessity of developing equipment that supplied both necessities. In the present study, a relatively simple and low cost device able to provide ways to the rotatory exercise of both upper and lower limbs simultaneously was projected and constructed with easily obtained accessible price materials. The cycle ergometer was built and gauged after the adaptation of a torquimeter, where the measures were recorded by a rotatory axis torque measure system through telemetry. It was accomplished a static and dynamic calibration on pedals and handles, which results showed that the developed equipment is able to accomplish independent rotation movements for both upper and lower limbs, isolately or entirely, allowing to pontentialize and amplify the list of benefits generated by the isolate devices. This equipment may be useful to rehabilitate patients bearing diverse pathologies as well as to the accomplishment of physical effort tests in rehabilitation departments and gyms

<p> In order to investigate possible negative effects of endurance training on muscle strength and power, 10 healthy young men underwent 10 weeks of endurance training. Subjects trained unilaterally on a cycle ergometer so that their opposite leg served as a control. Training consisted of 30 min per day for 3 days per week and progressed to 60 min per day for 5 days per week by the seventh week of training. This volume of endurance training exceeds the upper limits of that normally performed by athletes who compete in power sports. The exercise intensity was initially ~75% of pre-training maximum power output and was increased over time to maintain a training heart rate of 140-160 beats per minute. Endurance, strength, and power variables were assessed in each leg before and after the training period. Measurements included electrically stimulated twitch characteristics of the quadriceps, single-leg V̇O2peak and lactate threshold (Tlac), single-leg take-off vertical jump power indices from a force platform, and maximal leg press strength at a low-(60°/s) and high-velocity (300°/s). Needle biopsies were taken from the quadriceps femoris before and after the training period, and analyzed for fibre-type proportions, fibre area, oxidative enzyme activity and capillary density. Post-training, subjects increased leg V̇O2peak (7%) and Tlac in the trained leg. Leg press strength was unaffected by training. Vertical jump power was not impaired nor were evoked twitches. Following training, there was a decrease in % type IIb and an increase in % type IIa fibres (p<0.05). There were no significant changes in fibre area. Percent fibre area increased for type I and IIa and decreased for type IIb fibres in the trained leg (p<0.05). These data indicate that a 10-week endurance-training program increases aerobic power but does not impair muscle strength or power.</p> / Thesis / Master of Science (MSc)