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1.
Spinal Cord ; 53(5): 363-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25266695

RESUMO

STUDY DESIGN: Randomized controlled trial. OBJECTIVES: To evaluate the effectiveness of the physical activity guidelines (PAG) for adults with spinal cord injury (SCI) to improve aspects of physical fitness. SETTING: Community exercise facility. METHODS: Twenty-three participants (age: 40.4±11.6 years, C1-T11, 12.0±10.0 years post injury) were randomized into PAG training (n=12) or active control (CON, n=11) groups. PAG training was 2x per week for 16 weeks and involved 20 min of aerobic exercise at a moderate to vigorous intensity and three sets of 10 repetitions (at 50-70% 1 repetition maximum; 1RM). Pre- and post-testing included peak exercise and aerobic endurance tests on an arm ergometer and 1RM testing. RESULTS: Nineteen participants (PAG, n=11; CON, n=8) completed the 16-week training program and post-testing. There was a significant (P<0.05) increase in peak aerobic capacity (relative VO2peak: 17.2%, absolute VO2peak: 9.9%) and submaximal power output (26.3%) in the PAG group only. Increases in strength ranged from 11.5-38.9% and were significantly (P<0.05) different from CON for vertical bench press, seated row, and rickshaw press. Adherence to the exercise program was 85.2±8.3% for PAG, 44.4±34.3% for CON (P<0.01). CONCLUSION: The PAG for adults with SCI are sufficient to improve aspects of aerobic and muscular fitness and should be promoted as a means to improve physical capacity. SPONSORSHIP: Ontario Neurotrauma Foundation (ONF), Natural Sciences and Engineering Research Council (NSERC) of Canada.


Assuntos
Terapia por Exercício/métodos , Guias como Assunto/normas , Atividade Motora/fisiologia , Avaliação de Resultados em Cuidados de Saúde/normas , Aptidão Física/fisiologia , Traumatismos da Medula Espinal/reabilitação , Adulto , Canadá , Feminino , Humanos , Masculino , Força Muscular , Percepção da Dor , Cooperação do Paciente , Resistência Física
2.
Spinal Cord ; 52(5): 392-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24534780

RESUMO

STUDY DESIGN: Sixteen-week follow-up study. OBJECTIVE: To evaluate the efficacy of referral from a health-care provider to regular exercise combined with 16 weeks of counselling support following discharge from inpatient or outpatient spinal cord injury (SCI) rehabilitation. SETTING: Two rehabilitation centres in Canada. METHODS: Seventeen participants (age 42.1±10.6 years, C3-T12, ASIA impairment score A-C) were recruited at discharge from inpatient (n=9; 5.2±1.3 months post-injury) or outpatient (n=8; 14.2±3.8 months post-injury) rehabilitation and were given a referral for regular exercise. Telephone counselling support was provided and adherence to the prescribed program was monitored for 16 weeks. RESULTS: There was a nonsignificant difference in exercise adherence rates (percentage of available sessions attended) between participants discharged from inpatient (71.4±44.9%) and those from outpatient (39.5±27.2%) rehabilitation programs. The most common barriers to participation were physical health problems (50%) and transportation (36%). An exercise beliefs questionnaire revealed that participants value exercise at discharge from rehabilitation, despite the common report of a relative lack of confidence in their ability to perform or adapt aerobic and resistance exercises to their specific capabilities. CONCLUSION: A system of direct referral and ongoing counselling support following discharge from either inpatient or outpatient SCI rehabilitation appears to encourage sustained participation, although future health promotion strategies should continue to provide specific information about how to adapt and complete aerobic and resistance exercises. SPONSORSHIP: Rick Hansen Institute and Ontario Neurotrauma Foundation.


Assuntos
Terapia por Exercício/métodos , Atividade Motora/fisiologia , Encaminhamento e Consulta , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação , Adulto , Canadá , Aconselhamento , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Alta do Paciente , Centros de Reabilitação , Inquéritos e Questionários
3.
Spinal Cord ; 52(12): 874-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25179653

RESUMO

STUDY DESIGN: Cross-sectional. OBJECTIVES: To evaluate exercise equipment preferences and compare cardiometabolic demand for passive hybrid and arm-only exercise among adults with paraplegia (PP) and those with tetraplegia (TP). SETTING: Four community exercise programmes. METHODS: Thirty-six adults (mean age: 41.1±12.1 years) with chronic (11.4±10.7 years post injury) TP (C3-C8; n=17) or PP (T3-T12; n=19) were recruited. Participants completed 20 min of submaximal aerobic exercise at moderate to vigorous intensity on four types of aerobic exercise equipment: arm cycle ergometer (ACE), arm glider (AG), arm-leg recumbent stepper (ALRS), and arm-leg cycle ergometer (ALCE). Participants also completed 3 sets of 10 repetitions of resistance exercise using wall pulleys (WP) and weight stack (WS) equipment. A questionnaire was administered to evaluate equipment preference. Heart rate (HR) and oxygen uptake (VO2) were measured in a subset of participants (n=9) during submaximal aerobic exercise. RESULTS: Arm-only exercise modes were perceived as being safer than passive hybrid exercise modes. There were no differences in perceived enjoyment between equipment types and groups. There were significant group but not equipment differences in HR (TP: 101.4 bpm; PP: 124.9 bpm) and VO2 (TP: 6.5 ml•kg(-1)•min(-1); PP: 10.5 mL•kg(-1)•min(-1)) during submaximal aerobic exercise. CONCLUSION: In this cross-community assessment of exercise equipment preferences after spinal cord injury (SCI), arm-only exercise modes were perceived as safer than hybrid exercise modes and there were no differences between equipment types in physiological responses.


Assuntos
Terapia por Exercício/instrumentação , Preferência do Paciente/estatística & dados numéricos , Traumatismos da Medula Espinal/reabilitação , Adolescente , Adulto , Idoso , Braço/fisiologia , Estudos Transversais , Exercício Físico , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Paraplegia/reabilitação , Quadriplegia/reabilitação , Treinamento Resistido , Inquéritos e Questionários , Adulto Jovem
4.
Spinal Cord ; 51(6): 491-500, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23608809

RESUMO

OBJECTIVES: To systematically develop an evidence-informed leisure time physical activity (LTPA) resource for adults with spinal cord injury (SCI). SETTING: Canada. METHODS: The Appraisal of Guidelines, Research and Evaluation (AGREE) II protocol was used to develop a toolkit to teach and encourage adults with SCI how to make smart and informed choices about being physically active. A multidisciplinary expert panel appraised the evidence and generated specific recommendations for the content of the toolkit. Pilot testing was conducted to refine the toolkit's presentation. RESULTS: Recommendations emanating from the consultation process were that the toolkit be a brief, evidence-based resource that contains images of adults with tetraplegia and paraplegia, and links to more detailed online information. The content of the toolkit should include the physical activity guidelines (PAGs) for adults with SCI, activities tailored to manual and power chair users, the benefits of LTPA, and strategies to overcome common LTPA barriers for adults with SCI. The inclusion of action plans and safety tips was also recommended. CONCLUSION: These recommendations have resulted in the development of an evidence-informed LTPA resource to assist adults with SCI in meeting the PAGs. This toolkit will have important implications for consumers, health care professionals and policy makers for encouraging LTPA in the SCI community.


Assuntos
Atividades de Lazer , Atividade Motora , Educação de Pacientes como Assunto/métodos , Traumatismos da Medula Espinal/reabilitação , Canadá , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paraplegia/etiologia , Paraplegia/reabilitação , Projetos Piloto , Quadriplegia/etiologia , Quadriplegia/reabilitação , Traumatismos da Medula Espinal/complicações
5.
Spinal Cord ; 49(1): 125-30, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20531355

RESUMO

STUDY DESIGN: The study design used is cross-sectional. OBJECTIVES: The aim of this study is to examine muscle contractile and excitability characteristics during fatigue of the tibialis anterior in six individuals with chronic spinal cord injury (SCI) and matched able-bodied (AB) controls. SETTING: McMaster University, Hamilton, ON, Canada. METHODS: Muscle compound action potential (M-wave) characteristics, muscle twitch properties, and summated force were examined during a 2 min fatigue protocol of intermittent bursts at 30 Hz (4 s tetanus, 2 s rest) or maximal voluntary contraction (MVC). Evoked twitch responses were followed during a recovery period. RESULTS: M-wave amplitude was smaller in SCI (2.5 ± 1.6 mV in SCI, 5.7 ± 3.2 mV in AB) at baseline, but there was no change in M-wave amplitude or area during fatigue in either group. There was an increase in M-wave duration toward the end of recovery in the SCI group. Peak torque (PT) was not different between groups at baseline (3.8 ± 1.8 Nm in SCI, 3.7 ± 0.6 Nm in AB); PT potentiated significantly during fatigue in the AB, but not SCI group. There was significantly greater fatigue of both PT (43% decline) and summated force (57% decline) in the SCI group compared with the AB group (13% increase and 22% decline for PT and MVC, respectively). CONCLUSION: The dorsiflexor muscles in people with SCI are significantly more fatiguable than those in AB controls, but decreases in muscle excitability do not seem to be an important contributor to the increased fatiguability. The mechanisms behind the increased fatigue must lie distal to the muscle membrane.


Assuntos
Fadiga Muscular/fisiologia , Debilidade Muscular/diagnóstico , Músculo Esquelético/fisiopatologia , Paralisia/etiologia , Traumatismos da Medula Espinal/complicações , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Debilidade Muscular/etiologia , Músculo Esquelético/inervação
6.
Spinal Cord ; 49(11): 1103-27, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21647163

RESUMO

STUDY DESIGN: Systematic review. OBJECTIVES: To conduct a systematic review of evidence surrounding the effects of exercise on physical fitness in people with spinal cord injury (SCI). SETTING: Canada. METHODS: The review was limited to English-language studies (published prior to March 2010) of people with SCI that evaluated the effects of an exercise intervention on at least one of the four main components of physical fitness (physical capacity, muscular strength, body composition and functional performance). Studies reported at least one of the following outcomes: oxygen uptake/consumption, power output, peak work capacity, muscle strength, body composition, exercise performance or functional performance. A total of 166 studies were identified. After screening, 82 studies (69 chronic SCI; 13 acute SCI) were included in the review. The quality of evidence derived from each study was evaluated using established procedures. RESULTS: Most studies were of low quality; however, the evidence was consistent that exercise is effective in improving aspects of fitness. There is strong evidence that exercise, performed 2-3 times per week at moderate-to-vigorous intensity, increases physical capacity and muscular strength in the chronic SCI population; the evidence is not strong with respect to the effects of exercise on body composition or functional performance. There were insufficient high-quality studies in the acute SCI population to draw any conclusions. CONCLUSIONS: In the chronic SCI population, there is good evidence that exercise is effective in improving both physical capacity and muscular strength, but insufficient quality evidence to draw meaningful conclusions on its effect on body composition or functional capacity.


Assuntos
Composição Corporal/fisiologia , Terapia por Exercício/normas , Atividade Motora/fisiologia , Força Muscular/fisiologia , Traumatismos da Medula Espinal/reabilitação , Adulto , Medicina Baseada em Evidências , Humanos , Traumatismos da Medula Espinal/fisiopatologia
7.
Spinal Cord ; 49(11): 1088-96, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21647164

RESUMO

OBJECTIVES: To systematically develop evidence-informed physical activity guidelines to improve physical fitness in people with spinal cord injury (SCI). SETTING: This study was conducted in Canada. METHODS: The Appraisal of Guidelines, Research and Evaluation II guideline development protocol was used to develop exercise guidelines to improve physical capacity and muscular strength. The evidence base for the guideline development process consisted of a systematic review and quality appraisal of research examining the effects of exercise on physical fitness among people with SCI. A multidisciplinary expert panel deliberated the evidence and generated the guidelines. Pilot testing led to refinement of the wording and presentation of the guidelines. RESULTS: The expert panel generated the following guidelines: for important fitness benefits, adults with a SCI should engage in (a) at least 20 min of moderate to vigorous intensity aerobic activity two times per week and (b) strength training exercises two times per week, consisting of three sets of 8-10 repetitions of each exercise for each major muscle group. CONCLUSION: People with SCI, clinicians, researchers and fitness programmers are encouraged to adopt these rigorously developed guidelines.


Assuntos
Medicina Baseada em Evidências/normas , Atividade Motora , Guias de Prática Clínica como Assunto/normas , Traumatismos da Medula Espinal/reabilitação , Adulto , Humanos , Traumatismos da Medula Espinal/fisiopatologia
8.
Spinal Cord ; 48(3): 202-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19721452

RESUMO

STUDY DESIGN: A cross-sectional design. OBJECTIVES: To examine the length-tension relationship of dorsiflexion (DF) and plantarflexion (PF) muscle groups in seven individuals with chronic spinal cord injury (SCI; C2-T7; age 43+/-10.1 years) and compare it with a group of age and sex-matched able-bodied (AB) controls. SETTING: McMaster University, Hamilton, ON, Canada. METHODS: Isometric single twitch properties, 0.5-s tetanic contractions (SCI) and maximal voluntary contractions (AB) were measured at nine joint angles from 20 degrees DF to 20 degrees PF. RESULTS: In the DF muscles, peak-evoked twitch (PT) torque occurred at 20 degrees PF for SCI (3.4+/-1.1 N m) and AB (3.8+/-1.4 N m) with no difference in peak torque between groups, whereas peak summated force occurred at 10 degrees PF in AB and 20 degrees PF in SCI (P<0.01). In the PF muscles, PT torque occurred at 15 degrees DF in AB (18.6+/-2.6 N m) and at 5 degrees DF (6.8+/-3.3 N m; P<0.01) in SCI, and peak-summated force occurred at 15 degrees DF in AB. The SCI group did not show any change in PF peak-summated force with varying joint angles. Rates of contraction and relaxation were not different between the two groups. CONCLUSIONS: The results suggest a significant change in the length-tension relationship of the PF muscles after SCI, but no change in the DF muscle group. Rehabilitation programs should focus on maintaining PF muscle length in order to optimize muscle strength and function after SCI.


Assuntos
Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Tornozelo/anatomia & histologia , Fenômenos Biomecânicos , Estimulação Elétrica , Pé/patologia , Pé/fisiologia , Humanos , Contração Isométrica/fisiologia , Perna (Membro)/patologia , Perna (Membro)/fisiologia , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Relaxamento Muscular/fisiologia
9.
mBio ; 6(4)2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-26307166

RESUMO

UNLABELLED: Describing the viral diversity of wildlife can provide interesting and useful insights into the natural history of established human pathogens. In this study, we describe a previously unknown picornavirus in harbor seals (tentatively named phopivirus) that is related to human hepatitis A virus (HAV). We show that phopivirus shares several genetic and phenotypic characteristics with HAV, including phylogenetic relatedness across the genome, a specific and seemingly quiescent tropism for hepatocytes, structural conservation in a key functional region of the type III internal ribosomal entry site (IRES), and a codon usage bias consistent with that of HAV. IMPORTANCE: Hepatitis A virus (HAV) is an important viral hepatitis in humans because of the substantial number of cases each year in regions with low socioeconomic status. The origin of HAV is unknown, and no nonprimate HAV-like viruses have been described. Here, we describe the discovery of an HAV-like virus in seals. This finding suggests that the diversity and evolutionary history of these viruses might be far greater than previously thought and may provide insight into the origin and pathogenicity of HAV.


Assuntos
Hepatovirus/genética , Hepatovirus/isolamento & purificação , Filogenia , Focas Verdadeiras/virologia , Animais , Códon , Genoma Viral , Genótipo , Vírus da Hepatite A Humana/genética , Hepatovirus/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fígado/virologia , Pulmão/virologia , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , Baço/virologia , Replicação Viral
10.
J Gerontol A Biol Sci Med Sci ; 50(2): B97-104, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7874586

RESUMO

We examined the effects of 42 weeks of progressive weight-lifting training on dynamic muscle strength, peak power output in cycle ergometry, symptom limited endurance during progressive treadmill walking and stair climbing, knee extensor cross-sectional areas, and bone mineral density and content in healthy males and females aged 60-80 years, currently enrolled in a 2-year resistance training program. Subjects were randomized into either exercise (EX) or control (CON) groups (60-70 years: 38 males and 36 females; 70-80 years: 25 males and 43 females). EX trained several muscle groups twice per week for 42 weeks at intensities ranging from 50-80% of the load that they could lift once only (1 RM); CON did usual daily activities. After the 10 months there was no change in 1 RM strength in CON, but significant gains (mean increases up to 65%) in EX (no independent age or gender effects); 30% and 47% of the increase in 1 RM had occurred by 6 and 12 weeks, respectively. In EX, the 7.1% increase in peak cycling power output was significantly greater than in CON (+1.1%). The 17.8% improvement in symptom limited treadmill walking endurance was also greater than in CON (+3.4%), but the difference between groups during stair climbing was not significant (EX + 57%, CON + 33%). The cross-sectional areas of the knee extensors increased significantly by 5.5% in EX but were unchanged in CON. There were no changes in bone mineral density or content in either group. We conclude that long-term resistance training in older people is feasible and results in increases in dynamic muscle strength, muscle size, and functional capacity.


Assuntos
Osso e Ossos/fisiologia , Tolerância ao Exercício/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Levantamento de Peso/fisiologia , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Osso e Ossos/anatomia & histologia , Ergometria , Teste de Esforço , Estudos de Viabilidade , Feminino , Humanos , Vértebras Lombares/anatomia & histologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia , Resistência Física/fisiologia , Caminhada/fisiologia
11.
J Gerontol A Biol Sci Med Sci ; 51(6): B425-33, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8914492

RESUMO

We conducted a 2-year (42 weeks of consecutive training in each year, separated by 10 weeks of testing and vacation time) randomized, controlled trial of weight training in 142 healthy male and female subjects, aged 60 to 80 years. Measurements included dynamic strength, symptom-limited endurance in cycling, treadmill walking and stair climbing, muscle size, and bone mineral density and content of the lumbar spine and whole body. One hundred and thirteen subjects completed the study (57 exercise, 56 control), with a mean attendance of 85% among the exercisers. Muscle strength was unchanged in the control subjects but increased (collapsed across age and gender) from 32% (leg press) to 90% (military press) in the exercisers. Symptom-limited endurance in cycling, treadmill walking, and stair climbing increased in the exercisers by (mean +/- SE) 6.2 +/- 0.8%, 29.2 +/- 7.3%, and 57 +/- 12%, respectively; the only change in the controls was an unanticipated 33% increase in stair climbing performance during the first year. These values were unchanged in the controls. Cross-sectional area of the knee extensors increased by 8.7 +/- 0.9% in the trained subjects and was unchanged in controls. Measures of whole body, lumbar spine bone mineral density, and lumbar spine bone mineral content were unchanged in the exercisers, but whole body bone mineral content decreased by 1%. In contrast, there were small increases (< 4.0%) in bone mineral density among the controls. Long-term weight training proved to be a safe and well-tolerated mode of exercise for the elderly. Increased strength was associated with muscle hypertrophy in each year, and with increased endurance in cycling, walking, and stair climbing. There were no changes in bone mineral density but a small reduction in whole body bone mineral content.


Assuntos
Exercício Físico , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Músculos/fisiologia
12.
J Gerontol A Biol Sci Med Sci ; 52(6): B337-43, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9402935

RESUMO

The purpose of this study was to determine the effect of aging on the muscle length-tension relationship in the plantarflexor muscles of 10 subjects aged 20-30 yr (Mean = 23; 5 males, 5 females), 10 subjects aged 60-80 yr (Mean = 72.3; 5 males, 5 females), and 10 subjects over 80 yr (Mean = 84.1, 5 males, 5 females). Isometric twitch properties, maximum voluntary strength, passive tension, and range of motion were measured at five different joint angles [20 degrees dorsiflexion (DF), 10 degrees DF, 0 degree, 10 degrees plantarflexion (PF), and 20 degrees PF]. Active (evoked and voluntary) and passive torque production were maximal when the ankle was rotated into the DF positions for all three age groups, whereas the lowest values were recorded when the ankle was rotated into 20 degrees PF. Males were stronger than females at all joint angles (p < .01). Also, young adults were stronger than both elderly adult groups (p < .01). These results illustrate that despite the considerable age-associated loss in both voluntary and evoked strength in the plantarflexors, the optimal angle for torque production remains the same for younger and older adults.


Assuntos
Envelhecimento/fisiologia , Contração Muscular , Músculo Esquelético/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia
13.
J Gerontol A Biol Sci Med Sci ; 51(3): B202-7, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8630696

RESUMO

The purpose of this study was to examine changes in strength over time in a cohort of healthy elderly people who underwent assessments of ankle muscle function 12 years earlier. The isometric strength and contractile characteristics of the dorsiflexors and plantarflexors were studied in 11 male and 11 female subjects, ranging from 73-97 yrs (mean age 84 +/- 7.1 yrs). The same footplate apparatus was used as during the original testing. From 1982 to 1994, plantarflexor strength decreased 2.1% per year in females, and 2.5% per year in males (p < .01). The loss was relatively less in the dorsiflexor muscles; strength decreased 0.3% per year in females, and 0.8% per year in male (p > .05). There were no significant changes in evoked twitch torque in either muscle group, which may be due to the fact that passive tension of the connective tissue increased (p < .01) over the 12-year period. We conclude from this longitudinal assessment of ankle muscle function that the rate of loss of voluntary strength can vary considerably between antagonistic muscle groups. Factors influencing this variable loss warrant further investigation.


Assuntos
Envelhecimento/fisiologia , Músculo Esquelético/fisiologia , Idoso , Idoso de 80 Anos ou mais , Tornozelo , Feminino , Humanos , Contração Isométrica , Estudos Longitudinais , Masculino , Contração Muscular
14.
J Appl Physiol (1985) ; 63(5): 1956-60, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3693229

RESUMO

The purpose of this study was to investigate the acute effects of exercise on plasma high-density lipoprotein cholesterol (HDL-C) and to determine whether the magnitude of this response would be affected by the intensity of the exercise. Twelve men (19-41 yr) ran an equivalent distance (9-12 km) on a treadmill on two separate occasions. On one occasion the exercise was performed at a speed that elicited 60% of the subject's maximal O2 uptake (VO2max), and on the other occasion exercise was performed at a speed that elicited 90% of VO2max. Changes in total cholesterol, triglycerides (TG), HDL-C, HDL apoprotein A (HDL-A), HDL saturation, lactate (LA), and free fatty acids (FFA) were measured during the course of each run, and all values were corrected for changes in plasma volume as indicated by hematocrit. There were significant increases (P less than 0.01) in HDL-C, HDL-A, and HDL saturation with exercise at both intensities, but greater increases in HDL-C (25 vs. 14%) and HDL-A (18 vs. 8%) were observed with the higher intensity exercise. Plasma FFA and TG did not differ between conditions, but LA concentrations rose significantly during the high-intensity exercise. These results indicate that increases in HDL components can occur with a relatively moderate exercise session and that the magnitude of these increases are directly related to the exercise intensity.


Assuntos
HDL-Colesterol/sangue , Esforço Físico , Adulto , Apoproteínas/sangue , Colesterol/sangue , Humanos , Masculino , Consumo de Oxigênio , Triglicerídeos/sangue
15.
J Appl Physiol (1985) ; 76(6): 2461-6, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7928871

RESUMO

The effects of beta-blockade on skeletal muscle excitability and fatiguability during exercise were examined. Ten healthy males (mean age 21.9 +/- 1.1 yr) performed a 4-min fatigue protocol consisting of intermittent isometric voluntary contractions of the knee extensors in one leg. Subjects performed the exercise after treatment with placebo, 100 mg metoprolol, or an equipotent dose of propranolol (60 mg, n = 1; 80 mg, n = 8; 100 mg, n = 1) twice a day for 76 h before testing according to a randomized double-blind design. The evoked twitch torque, maximal voluntary torque, and maximal M-wave amplitude were unaffected by the beta-blockade treatments before fatigue. During the placebo trial, there were significant reductions in the evoked and voluntary torques (77 +/- 15 and 55 +/- 11%, respectively) after the fatigue protocol; however, both the voluntary electromyogram and evoked M waves were well maintained throughout fatigue. The beta-blockade treatments had no significant effect on torque or electromyogram activity over the course of the exercise. Thus, despite evidence for an impairment of dynamic exercise performance with beta 1- and beta 1,2-blockade, there appears to be no effect of these agents on muscle excitability and fatiguability during isometric muscle activity.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Fadiga Muscular/fisiologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Antagonistas de Receptores Adrenérgicos beta 1 , Antagonistas de Receptores Adrenérgicos beta 2 , Adulto , Método Duplo-Cego , Eletromiografia/efeitos dos fármacos , Teste de Esforço , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Contração Isométrica/efeitos dos fármacos , Masculino , Metoprolol/farmacologia , Contração Muscular/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Consumo de Oxigênio/fisiologia , Propranolol/farmacologia , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/fisiologia
16.
J Appl Physiol (1985) ; 84(6): 2138-42, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9609810

RESUMO

Our purpose was to examine the effects of sprint interval training on muscle glycolytic and oxidative enzyme activity and exercise performance. Twelve healthy men (22 +/- 2 yr of age) underwent intense interval training on a cycle ergometer for 7 wk. Training consisted of 30-s maximum sprint efforts (Wingate protocol) interspersed by 2-4 min of recovery, performed three times per week. The program began with four intervals with 4 min of recovery per session in week 1 and progressed to 10 intervals with 2.5 min of recovery per session by week 7. Peak power output and total work over repeated maximal 30-s efforts and maximal oxygen consumption (VO2 max) were measured before and after the training program. Needle biopsies were taken from vastus lateralis of nine subjects before and after the program and assayed for the maximal activity of hexokinase, total glycogen phosphorylase, phosphofructokinase, lactate dehydrogenase, citrate synthase, succinate dehydrogenase, malate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase. The training program resulted in significant increases in peak power output, total work over 30 s, and VO2 max. Maximal enzyme activity of hexokinase, phosphofructokinase, citrate synthase, succinate dehydrogenase, and malate dehydrogenase was also significantly (P < 0.05) higher after training. It was concluded that relatively brief but intense sprint training can result in an increase in both glycolytic and oxidative enzyme activity, maximum short-term power output, and VO2 max.


Assuntos
Adaptação Fisiológica/fisiologia , Músculo Esquelético/fisiologia , Aptidão Física/fisiologia , Corrida/fisiologia , Adulto , Anaerobiose/fisiologia , Metabolismo Energético/fisiologia , Glicogênio/metabolismo , Humanos , Masculino , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Oxirredução , Consumo de Oxigênio/fisiologia
17.
Bioresour Technol ; 77(2): 131-8, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11272019

RESUMO

The yields of char residue, fixed carbon, and inorganic carbonate were measured for oxidized black liquor char residues produced in a laboratory laminar entrained-flow reactor (LEFR) at heating rates of 4000-13,000 degrees C/s. The char residue yields at the end of devolatilization thus obtained decreased nearly linearly with temperature, from 75% at 700 degrees C to 58% at 1100 degrees C. There were explainable differences in the char residue yields from the liquor used in this study and those used in other studies. Char residue yields seemed to depend mainly on the temperature to which the particles or droplets were exposed and were not very sensitive to heating rate. Fixed carbon yields behaved similarly to those of the char residue. The fixed carbon remaining at the end of devolatilization decreased from 67% at 700 degrees C to about 45% at 1100 degrees C. The carbonate content in black liquor changed very little before and after devolatilization.


Assuntos
Carbono/análise , Carbonatos/análise , Resíduos Industriais , Árvores , Temperatura Alta
18.
Spinal Cord ; 46(3): 216-21, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17646838

RESUMO

STUDY DESIGN: Prospective, observational cohort study. OBJECTIVES: This paper describes the rationale and methodology for the Study of Health and Activity in People with Spinal Cord Injury (SHAPE SCI). The study aims to (1) describe physical activity levels of people with different injury levels and completeness, (2) examine the relationship between physical activity, risk and/or presence of secondary health complications and risk of chronic disease, and (3) identify determinants of physical activity in the SCI population. SETTING: Ontario, Canada. METHODS: Seven hundred and twenty men and women who have incurred a traumatic SCI complete self-report measures of physical activity, physical activity determinants, secondary health problems and subjective well-being during a telephone interview. A representative subsample (n=81) participate in chronic disease risk factor testing for obesity, insulin resistance and coronary heart disease. Measures are taken at baseline, 6 and 18 months. CONCLUSION: SHAPE SCI will provide much-needed epidemiological information on physical activity patterns, determinants and health in people with SCI. This information will provide a foundation for the establishment of evidence-based physical activity guidelines and interventions tailored to the SCI community.


Assuntos
Medicina Baseada em Evidências/métodos , Guias como Assunto , Atividade Motora/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Estudos de Coortes , Doença das Coronárias/etiologia , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Resistência à Insulina/fisiologia , Entrevistas como Assunto , Masculino , Obesidade/etiologia , Obesidade/fisiopatologia , Ontário , Estudos Prospectivos , Fatores de Risco , Traumatismos da Medula Espinal/complicações
19.
Spinal Cord ; 43(10): 577-86, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15838527

RESUMO

Symptoms of spasticity are often experienced by individuals with spinal cord injury (SCI) following a period of spinal shock and, in many cases, these symptoms negatively affect quality of life. Despite its prevalence, spasticity as a syndrome in the SCI population is not always managed effectively. This is likely due to the fact that the syndrome can have various presentations, each with their own specific etiology. This overview summarizes the symptoms and pathophysiology of the various presentations of spasticity in the SCI population and discusses the currently accepted management techniques. There is a need for a better understanding of the syndrome of spasticity as well as the development of a valid and reliable assessment tool.


Assuntos
Espasticidade Muscular/etiologia , Traumatismos da Medula Espinal/complicações , Baclofeno/uso terapêutico , Humanos , Injeções Espinhais , Relaxantes Musculares Centrais/uso terapêutico , Espasticidade Muscular/terapia
20.
Spinal Cord ; 43(5): 291-8, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15685260

RESUMO

STUDY DESIGN: Longitudinal, prospective within-subject design. OBJECTIVES: (1) To determine the effects of long-term body-weight-supported treadmill training (BWSTT) on functional walking ability and perceived quality of life in persons with chronic incomplete spinal cord injury (SCI), and (2) to investigate whether training adaptations are maintained following cessation of the BWSTT programme. SETTING: Hamilton, Ontario, Canada. METHODS: A group of 14 individuals with chronic (mean 7.4 years postinjury) incomplete SCI (ASIA B & C) participated in thrice-weekly sessions of BWSTT for a period of approximately 12 months (144 sessions). Functional walking ability and indices of subjective well-being were evaluated during the training programme and over an 8-month follow-up. RESULTS: In total, 13 subjects successfully completed the 144 training sessions in the required study period (max. 15 months). Adherence to the thrice-weekly training frequency was 78.8%. All subjects improved in treadmill walking ability (54% reduction in required external body-weight support (BWS), 180% increase in treadmill walking speed, 335% increase in distance walked/session), and six subjects improved their capacity to walk over ground. There were accompanying increases in satisfaction with life and satisfaction with physical function, both of which were significantly correlated with improvements in treadmill walking ability. All but one subject returned for follow-up assessment 8 months post-training; while there was a slight decline in treadmill walking performance, over ground walking scores remained relatively stable. The only change in subjective well-being in the follow-up was a slight decrease in satisfaction with physical function. CONCLUSION: Thrice-weekly BWSTT for 12 months was an effective stimulus to improve treadmill walking ability and indices of subjective well-being in persons with chronic incomplete SCI, and most of these improvements were maintained for up to 8 months following the cessation of training.


Assuntos
Modalidades de Fisioterapia , Traumatismos da Medula Espinal , Tempo , Caminhada , Suporte de Carga/fisiologia , Atividades Cotidianas , Adulto , Análise de Variância , Doença Crônica , Avaliação da Deficiência , Teste de Esforço/métodos , Feminino , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Autoimagem , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/psicologia , Traumatismos da Medula Espinal/reabilitação , Fatores de Tempo , Resultado do Tratamento
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