Can group exercise programs improve health outcomes in pregnant women? A systematic review

Current scientific evidence supports the recommendation to initiate or continue the practice of physical exercise in healthy pregnant women. Group exercise programs have positive effects in improving health and well-being, as well as social support. In order to understand the scientific evidence in this field, and the outcomes in maternal health, it has generated wide interest in exploring the studies carried out with more relevant group exercise programs. The aim of this systematic review was to evaluate the available evidence on the effectiveness of group exercise programs in improving women’s and newborns health outcomes during pregnancy. Three databases were used to conduct literature searches and strict inclusion and exclusion criteria were employed. Seventeen studies were selected for analysis. All studies were randomized control trials conducted with pregnant women that evaluated the effect of group exercise programs on the health outcomes of mother and newborn. Most studies followed a supervised structured exercise program including a main aerobic part, resistance training, pelvic floor training and stretching and relaxation sections. The significant effects of the programs are related with improved maternal perception of health status, lower maternal weight gain, improved levels of maternal glucose tolerance, improved aerobic fitness and muscular strength, lower frequency of urinary incontinence, improved sick leave due to lumbopelvic pain, fewer cesarean and instrumental deliveries, higher newborn Apgar score and faster postpartum recovery. Exercise and health professionals should advise pregnant women that aerobic group exercise during pregnancy improves a wide range of health outcomes for the women and newborn

Influence of a lifestyle intervention in preschool children on physiological and psychological parameters (Ballabeina): study design of a cluster randomized controlled trial.

Childhood obesity and physical inactivity are increasing dramatically worldwide. Children of low socioeconomic status and/or children of migrant background are especially at risk. In general, the overall effectiveness of school-based programs on health-related outcomes has been disappointing. A special gap exists for younger children and in high risk groups. This paper describes the rationale, design, curriculum, and evaluation of a multicenter preschool randomized intervention study conducted in areas with a high migrant population in two out of 26 Swiss cantons. Twenty preschool classes in the German (canton St. Gallen) and another 20 in the French (canton Vaud) part of Switzerland were separately selected and randomized to an intervention and a control arm by the use of opaque envelopes. The multidisciplinary lifestyle intervention aimed to increase physical activity and sleep duration, to reinforce healthy nutrition and eating behaviour, and to reduce media use. According to the ecological model, it included children, their parents and the teachers. The regular teachers performed the majority of the intervention and were supported by a local health promoter. The intervention included physical activity lessons, adaptation of the built infrastructure; promotion of regional extracurricular physical activity; playful lessons about nutrition, media use and sleep, funny homework cards and information materials for teachers and parents. It lasted one school year. Baseline and post-intervention evaluations were performed in both arms. Primary outcome measures included BMI and aerobic fitness (20 m shuttle run test). Secondary outcomes included total (skinfolds, bioelectrical impedance) and central (waist circumference) body fat, motor abilities (obstacle course, static and dynamic balance), physical activity and sleep duration (accelerometry and questionnaires), nutritional behaviour and food intake, media use, quality of life and signs of hyperactivity (questionnaires), attention and spatial working memory ability (two validated tests). Researchers were blinded to group allocation. The purpose of this paper is to outline the design of a school-based multicenter cluster randomized, controlled trial aiming to reduce body mass index and to increase aerobic fitness in preschool children in culturally different parts of Switzerland with a high migrant population. Trial Registration: (clinicaltrials.gov) NCT00674544.

An international investigation on the validity of the CSAPPA scale in screening for developmental coordination disorder /

The main objective of the present investigation was to continue the research initiated by Hay and colleagues (2004) in examining the efficacy of the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA) scale as a proxy for the short form of the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP-SF) in screening for Developmental Coordination Disorder (DCD) in children. To better appreciate DCD knowledge outside Canada, the measurements of this investigation were expanded in Greece. A translated Greek CSAPP A scale and the BOTMP-SF were administered for the first time in Greek children. A second objective was to investigate the relationship between DCD and various risk factors of coronary artery disease (CAD) in Canadian and Greek children. A sample of 591 (Ms=322; Fs=269) Canadian and 392 (Ms=211; Fs=181) Greek children, aged 9 to 13 years, consented to the BOTMP-SF, CSAPP A Scale, participation in physical activity questionnaire, Leger 20-meter Multistage Shuttle Run test, and body fat using bioelectric impedance. Prevalence of DCD in Canada and Greece was 8% and 19%, respectively. Significant agreement (paerobic fitness levels and BOTMP-SF compared to their Greek peers. Clumsiness was associated with increased percent body fat and low aerobic fitness values. Physical activity was a significant mediator in the clumsiness-aerobic fitness relationship. It is concluded that the CSAPPA scale is an accurate, practical, and inexpensive screening tool for DCD, and that motoric competence is associated with aerobic fitness through physical activity participation.

Comprehensive school health, the social determinants of health, and the health status of children

As children are becoming increasingly inactive and obese, there is an urgent need for effective early prevention and intervention programs. One solution is a comprehensive school health (CSH) program, a health promotion initiative aimed at educating students about healthy behaviours and lifestyles, which also provides a link between the school, students, families, and the surrounding community. The purpose of this study was to explore the relationship between different components of CSH programs, as well as three determinants of health (gender, social support, socio-economic status), and physical activity, on the aerobic fitness and body mass index (BMI) of children. A newly developed and pilot-tested survey derived from Health Canada's fourpart CSH model (instruction, social support, support services, and a healthy physical environment) was sent to elementary school principals. Data on the gender, physical activity, parental education, and social support levels of students from these schools were gathered from a previous study. Multiple regression procedures were conducted to estimate the relationships between CSH components, the social determinants of health, physical activity, and BMI and aerobic fitness. Results showed that three CSH components were significantly associated with both BMI and aerobic fitness values in children, but accounted for less than 5% of the variance in both variables. Physical activity partially mediated the relationship between the significant CSH components, BMI, and particularly aerobic fitness. Furthermore, the social determinant and physical activity variables played independent roles in aerobic fitness values. No moderating effects of the social determinants were discovered.

The influence of recreational ball hockey play on cardiovascular risk factors in sedentary males

Introduction: The prevalence of coronary artery disease (CAD) is ever increasing in western industrialized societies. An individuals overall risk for CAD may be quantified by integrating a number of factors including, but not limited to, cardiorespiratory fitness, body composition, blood lipid profile and blood pressure. It might be expected that interventions aimed at improving any or all of these independent factors might improve an individual 's overall risk. To this end, the influence of standard endurance type exercise on cardiorespiratory fitness, body composition, blood lipids and blood pressure, and by extension the reduction of coronary risk factors, is well documented. On the other hand, interval training (IT) has been shown to provide an extremely powerful stimulus for improving indices of cardiorespiratory function but the influence of this training type on coronary risk factors is unknown. Moreover, the vast majority of studies investigating the effects of IT on fitness have used laboratory type training protocols. As a result of this, the influence of participation in interval-type recreational sports on cardiorespiratory fitness and coronary risk factors is unknown. Aims: The aim of the present study was to evaluate the effectiveness of recreational ball hockey, a sport associated with interval-type activity patterns, on indices of aerobic function and coronary risk factors in sedentary men in the approximate age range of 30 - 60 years. Individual risk factors were compiled into an overall coronary risk factor score using the Framingham Point Scale (FPS). Methods: Twenty-four sedentary males (age range 30 - 60) participated in the study. Subject activity level was assessed apriori using questionnaire responses. All subjects (experimental and control) were assessed to have been inactive and sedentary prior to participation in the study. The experimental group (43 ± 3 years; 90 ± 3 kg) (n = 11) participated in one season of recreational ball hockey (our surrogate for IT). Member of this group played a total of 16 games during an 11 week span. During this time, the control group (43 ± 2 years; 89 ± 2 kg) (n = 11) performed no training and continued with their sedentary lifestyle. Prior to and following the ball hockey season, experimental and control subjects were tested for the following variables: 1) cardiorespiratory fitness (as V02 Max) 2) blood lipid profile 3) body composition 5) waist to hip ratio 6) blood glucose levels and 7) blood pressure. Subject V02 Max was assessed using the Rockport submaximal walking test on an indoor track. To assess body composition we determined body mass ratio (BMI), % body fat, % lean body mass and waist to hip ratio. The blood lipid profile included high density lipoprotein, low density lipoprotein and total cholesterol levels; in addition, the ratio of total cholesterol to high density was calculated. Blood triglycerides were also assessed. All data were analyzed using independent t - tests and all data are expressed as mean ± standard error. Statistical significance was accepted at p :S 0.05. Results: Pre-test values for all variables were similar between the experimental and control group. Moreover, although the intervention used in this study was associated with changes in some variables for subjects in the experimental group, subjects in the control group did not exhibit any changes over the same time period. BODY COMPOSITION: The % body fat of experimental subjects decreased by 4.6 ± 0.5%, from 28.1 ± 2.6 to 26.9 ± 2.5 % while that of the control group was unchanged at 22.7 ± 1.4 and 22.2 ± 1.3 %. However, lean body mass of experimental and control subjects did not change at 64.3 ± 1.3 versus 66.1 ± 1.3 kg and 65.5 ± 0.8 versus 64.7 ± 0.8 kg, respectively. In terms of body mass index and waist to hip ratio, neither the experimental nor the control group showed any significant change. Respective values for the waist to hip ratio and body mass index (pre and post) were as follows: 1 ± 0.1 vs 0.9 ± 0.1 (experimental) and 0.9 ± 0.1 versus 0.9 ± 0.1 (controls) while for BMI they were 29 ± 1.4 versus 29 ± 1.2 (experimental) and 26 ± 0.7 vs. 26 ± 0.7 (controls). CARDIORESPIRATORY FITNESS: In the experimental group, predicted values for absolute V02 Max increased by 10 ± 3% (i.e. 3.3 ± 0.1 to 3.6 ± 0.1 liters min -1 while that of control subjects did not change (3.4 ± 0.2 and 3.4 ± 0.2 liters min-I). In terms of relative values for V02 Max, the experimental group increased by 11 ± 2% (37 ± 1.4 to 41 ± 1.4 ml kg-l min-I) while that of control subjects did not change (41 ± 1.4 and 40 ± 1.4 ml kg-l min-I). BLOOD LIPIDS: Compared to pre-test values, post-test values for HDL were decreased by 14 ± 5 % in the experiment group (from 52.4 ± 4.4 to 45.2 ± 4.3 mg dl-l) while HDL data for the control group was unchanged (49.7 ± 3.6 and 48.3 ± 4.1 mg dl-l, respectively. On the other hand, LDL levels did not change for either the experimental or control group (110.2 ± 10.4 versus 112.3 ± 7.1 mg dl-1 and 106.1 ± 11.3 versus 127 ± 15.1 mg dl-1, respectively). Further, total cholesterol did not change in either the experimental or control group (181.3 ± 8.7 mg dl-1 versus 178.7± 4.9 mg dl-l) and 190.7 ± 12.2 versus 197.1 ± 16.1 mg dl-1, respectively). Similarly, the ratio of TC/HDL did not change for either the experimental or control group (3.8 ± 0.4 versus 4.5 ± 0.5 and 4 ± 0.4 versus 4.2 ± 0.4, respectively). Blood triglyceride levels were also not altered in either the experimental or control group (100.3 ± 19.6 versus 114.8 ± 15.3 mg dl-1 and 140 ± 23.5 versus 137.3 ± 17.9 mg dl-l, respectively). BLOOD GLUCOSE: Fasted blood glucose levels did not change in either the experimental or control group. Pre- and post-values for experimental and control groups were 92.5 ± 4.8 versus 93.3 ± 4.3 mg dl-l and 92.3 ± 11.3 versus 93.2 ± 2.6 mg dl-1 , respectively. BLOOD PRESSURE: No aspect of blood pressure was altered in either the experimental or control group. For example, pre- and post-test systolic blood pressures were 131 ± 2 versus 129 ± 2 mmHg (experimental) and 123 ± 2 and 125 ± 2 mmHg (controls), respectively. Pre- and post-test diastolic blood pressures were 84 ± 2 and 83 ± 2 mmHg (experimental) and 81 ± 1 versus 82 ± 1 mmHg, respectively. Similarly, calculated pulse pressure was not altered in the experimental or control as pre- and post-test values were 47 ± 1 versus 47 ± 2 mmlHg and 42 ± 2 versus 43 ± 2 mmHg, respectively. FRAMINGHAM POINT SCORE: The concerted changes reported above produced an increased risk in the Framingham Point Score for the subjects in the experimental group. For example, the pre- and post-test FPS increased from 1.4 ± 0.9 to 2.7 ± 0.7. On the other hand, pre- and post-test scores for the control group were 1.8 ± 1 versus 1.8 ± 0.9. Conclusions: Our data confirms previous studies showing that interval-type exercise is a useful intervention for increasing aerobic fitness. Moreover, the increase in V02 Max we found in response to limited participation in ball hockey (i.e. 16 games) suggests that recreational sport may help reduce this aspect of coronary risk in previously sedentary individual. On the other hand, our results showing little or no positive change in body composition, blood lipids or blood pressures suggest that one season of recreational sport in not in of itself a powerful enough stimulus to reduce the overall risk of coronary artery disease. In light of this, it is recommended that, in addition to participation in recreational sport, the performance of regular physical activity is used as an adjunct to provide a more powerful overall stimulus for decreasing coronary risk factors. LIMITATIONS: The increase in the FPS we found for the experimental group, indicative of an increased risk for coronary disease, was largely due to the large decrease in HDL we observed after compared to above one season of ball hockey. In light of the fact that cardiorespiratory fitness was increased and % body fat was decreased, as well as the fact that other parameters such as blood pressure showed positive (but non statistically significant) trends, the possibility that the decrease in HDL showed by our data was anomalous should be considered. FUTURE DIRECTIONS: The results of this study suggesting that recreational sport may be a potentially useful intervention in the reduction of CAD require to be corroborated by future studies specifically employing 1) more rigorous assessment of fitness and fitness change and 2) more prolonged or frequent participants.

Capacidad aeróbica de bomberos aeronáuticos

Los bomberos aeronáuticos son los encargados de atender todas las emergencias en los aeropuertos y sus cercanías. Estas emergencias incluyen emergencias aéreas, en tierra, eventos con materiales peligros e incendios, entre otros. Su trabajo tiene como características la realización de actividades durante periodos largos de baja intensidad y periodos cortos de alta intensidad. De acuerdo con estas características, es necesario que los bomberos aeronáuticos tengan una buena condición física. El consumo máximo de oxígeno (VO2 máx) como indicador de capacidad aeróbica resulta indispensable para conocer el desempeño de los bomberos en su trabajo. El objetivo de este estudio es determinar la capacidad aeróbica de los bomberos aeronáuticos y sus factores determinantes. Por tanto se desarrolló un estudio transversal de tipo descriptivo en una muestra de 23 hombres bomberos aeronáuticos. Se obtuvo información acerca de sus variables socio-demográficas, se determinó el VO2 máx y umbral ventilatorio mediante análisis de gases espirados durante un protocolo de ejercicio máximo sobre tapiz rodante, se evaluó la composición corporal mediante adipometría y se determinó el nivel de actividad física mediante el cuestionario internacional de actividad física IPAQ. Se encontró que la muestra tenia una edad de 32,6 ± 4,8 años, peso de 78,4 ± 9,8 kg, porcentaje de grasa de 14,8 ± 3,8 %, índice de masa corporal de 25,7 ± 2,7 y VO2máx de 44,6 ± 6. No se encontraron cambios significativos del VO2máx con la edad, pero si con la actividad física, porcentaje de grasa e índice de masa corporal. Se sugiere que el entrenamiento de los bomberos aeronáuticos durante su jornada laboral sea de intervalos de alta intensidad y que se monitorice su nivel de actividad física y composición corporal.

Revisión sistemática: programas de ejercicio en rehabilitación cardiaca intrahospitalaria versus rehabilitación cardiaca en casa para pacientes con evento coronario agudo

El objetivo de la rehabilitación cardiaca es lograr que los pacientes con enfermedades cardiacas, reanuden su vida activa y productiva; logrando un óptimo estado físico, psicosocial y vocacional. Los programas de ejercicio, son parte básica de la rehabilitación cardiaca. Existen muchos tipos de programas de actividad física, que varían entre programas de ejercicio en casa no supervisados, hasta programas intrahospitalarios altamente supervisados.

Niveles de actividad física, condición física y tiempo en pantallas en escolares de Bogotá, Colombia: Estudio FUPRECOL

Examina la relación entre los niveles de actividad física (AF) de forma objetiva, la condición física (CF) y el tiempo de exposición a pantallas en niños y adolescentes de Bogotá, Colombia.

Factores de riesgo del comportamiento y readiness de aficionados inscritos a carreras atléticas de fondo de 18-64 años en Bogotá D.C., 2014”

La participación en carreras atléticas de calle ha aumentado; esto requiere detectar riesgos previos al esfuerzo físico. Objetivo. Identificar factores de riesgo del comportamiento y readiness de inscritos a una carrera. Método. Estudio transversal en aficionados de 18-64 años. Encuesta digital con módulos de IPAQ, PARQ+ y STEP. Muestreo aleatorio sistemático con n=510, para una inactividad física esperada de 35% (±5%). Se evaluó nivel de actividad física, consumo de alcohol (peligroso), de fruta, verdura, tabaco y sal, y readiness. Resultados. El cumplimiento de actividad física fue 97,4%; 2,4% consume nivel óptimo de fruta o verdura (diferencias por edad, sexo y estrato), 3,7% fuma y 44,1% consumo peligroso de alcohol. El 19,8% reportó PARQ+ positivo y 5,7% requiere supervisión. Hay diferencias por trabajo y estudio. Discusión. Los aficionados cumplen el nivel de actividad física; pero no de otros factores. Una estrategia de seguridad en el atletismo de calle es evaluar los factores de riesgo relacionados con el estilo de vida así como el readiness.

Relação das actividades desportivas não lectivas e a aptidão física nos alunos do Ensino Secundário (estudo efectuado em 4 escolas da rede de Estágios da ULHT 2010/211)

RESUMO: Actividade Física, é qualquer movimento corporal produzido pelos músculos esqueléticos que resultam em energia despendida, acima do nível de repouso (Caspersen et al1985; Baranowski et al 1992). Um indivíduo sedentário que comece uma Actividade Física regular desencadeia um conjunto de adaptações ao esforço, em que algumas destas adaptações serão benéficas em termos de saúde, ajudando na prevenção inicial de várias doenças (Haskell et al 1965; Barata et al 1997). A Aptidão Física é um conjunto de atributos que as pessoas têm ou alcançam, que estão relacionados com os movimentos que as pessoas desempenham (Caspersen et al 1985; Baranowski et al 1992). O objectivo central do presente estudo consistiu em verificar se existem diferenças significativas entre os Praticantes e Não Praticantes de ADEC e a Aptidão Física dos alunos. A amostra foi constituída por 310 sujeitos, 165 rapazes e 145 raparigas pertencentes ao Ensino Secundário de 4 escolas da rede de estágios da ULHT 2010/2011. As Capacidades Físicas foram avaliadas através dos testes do Fitnessgram, a Prática de ADEC e o Índice de Actividade Física foram obtidos através do Questionário de Actividade Desportiva. Conclusões: Os alunos que praticam ADEC são mais aptos do que os alunos que não praticam ADEC. Estes Praticantes apresentam valores mais elevados na Aptidão Aeróbia e no VO2máx., quando comparados com os Não Praticantes. Nas restantes Capacidades Físicas analisadas (Força de Braços, Força Abdominal e Flexibilidade) não foram encontradas diferenças significativas. Não foram encontradas diferenças significativas entre a Prática de ADEC e o IMC. Os Praticantes de ADEC demonstraram ter um IAF superior aos Não Praticantes de ADEC. O Género Feminino apresenta melhores resultados do que o Género Masculino para a Força de Braços. Nas restantes Capacidades Físicas não foram encontradas diferenças significativas entre Géneros. Quando analisado o IMC, o Género Feminino apresenta percentagens superiores de Peso Normal relativamente ao Género Masculino. Não foram encontradas diferenças significativas entre o Género e a Aptidão Física. Verificou-se que existe diferenças significativas na relação entre o Género e o IAF, o Género Masculino tem um IAF superior ao Género Feminino. Os alunos mais aptos fisicamente são os alunos com maior IAF. Não foram encontradas diferenças significativas entre as Modalidades praticadas pelos alunos e o desenvolvimento qualquer das Capacidades Físicas estudadas. ABSTRACT: Physical Activity is any body movement produced by skeletal muscles resulting in energy expenditure above the resting level (Caspersen et al1985; Baranowski et al 1992). A sedentary individual, who starts a regular Physical Activity, triggers a set of adaptations to stress, in which some of these changes will be helpful in terms of health, aiding in primary prevention of several diseases (Haskell et al 1965; Barata et al 1997). Physical Fitness is a set of attributes that people have or achieve, and are related with the movements that people perform (Caspersen et al 1985; Baranowski et al 1992). The main purpose of this study was to determine whether there are significant differences between Practicing and Non-practitioners of ADEC and Physical Fitness of students. The sample consisted of 310 subjects, 165 boys and 145 girls belonging to high school students of 4 schools integrated in the ULHT 2010/2011. The Physical Abilities were assessed through Fitnessgram tests, ADEC practice and the Index of Physical Activity were obtained through the Physical Activity Questionnaire. Conclusions: Students that practice ADEC are more able than students who do not practice ADEC. These students that practice ADEC have higher values in Aerobic Fitness and VO2max when compared to non-practicing students. In the remaining Physical Abilities analyzed (Arm Strength, Abdominal Strength and Flexibility) were not considered significant differences. No significant differences were found between ADEC practice and the BMI. The students that practice ADEC showed higher Physical Activity levels than students who do not practice. Female gender presents better results than the male gender in Arms strength. In the remaining components of Physical Fitness were not found significant differences between genders. When analyzed BMI, female gender has higher percentages of normal weight compared to male gender. No significant differences were found between Gender and Physical Fitness. It was verified that there are significant differences in the relation between gender and Physical Activity levels, the male gender have a higher level of Physical Activity than female gender. The most able students are the ones with higher levels of Physical Activity. There were no significant differences between the sports practiced by students and the development of the studied components of physical fitness.

PPARGC1A sequence variation and cardiovascular risk-factor levels: a study of the main genetic effects and gene x environment interactions in children from the European Youth Heart Study.

AIMS/HYPOTHESIS: The PPARGC1A gene coactivates multiple nuclear transcription factors involved in cellular energy metabolism and vascular stasis. In the present study, we genotyped 35 tagging polymorphisms to capture all common PPARGC1A nucleotide sequence variations and tested for association with metabolic and cardiovascular traits in 2,101 Danish and Estonian boys and girls from the European Youth Heart Study, a multicentre school-based cross-sectional cohort study. METHODS: Fasting plasma glucose concentrations, anthropometric variables and blood pressure were measured. Habitual physical activity and aerobic fitness were objectively assessed using uniaxial accelerometry and a maximal aerobic exercise stress test on a bicycle ergometer, respectively. RESULTS: In adjusted models, nominally significant associations were observed for BMI (rs10018239, p = 0.039), waist circumference (rs7656250, p = 0.012; rs8192678 [Gly482Ser], p = 0.015; rs3755863, p = 0.02; rs10018239, beta = -0.01 cm per minor allele copy, p = 0.043), systolic blood pressure (rs2970869, p = 0.018) and fasting glucose concentrations (rs11724368, p = 0.045). Stronger associations were observed for aerobic fitness (rs7656250, p = 0.005; rs13117172, p = 0.008) and fasting glucose concentrations (rs7657071, p = 0.002). None remained significant after correcting for the number of statistical comparisons. We proceeded by testing for gene x physical activity interactions for the polymorphisms that showed nominal evidence of association in the main effect models. None of these tests was statistically significant. CONCLUSIONS/INTERPRETATION: Variants at PPARGC1A may influence several metabolic traits in this European paediatric cohort. However, variation at PPARGC1A is unlikely to have a major impact on cardiovascular or metabolic health in these children.

Slow component of VO2 kinetics: the effect of training status, fibre type, UCP3 mRNA and citrate synthase activity

Examines the relationship between the magnitude of the relative slow component (SC) of pulmonary oxygen uptake VO[sub 2], citrate synthase activity, UCP2 and UCP3 mRNA levels and muscle fiber composition in both endurance-trained and recreationally active subjects. Magnitude of the relative SC of the Tr group; Indicators of aerobic fitness; High negative correlations between the magnitude of the relative SC and citrate synthase activity and VO[sub 2] peak.

Máxima fase estável de lactato sanguíneo e potência crítica em ciclistas bem treinados

O principal objetivo deste estudo foi comparar a intensidade correspondente à máxima fase estável de lactato (MLSS) e a potência crítica (PC) durante o ciclismo em indivíduos bem treinados. Seis ciclistas do sexo masculino (25,5 ± 4,4 anos, 68,8 ± 3,0kg, 173,0 ± 4,0cm) realizaram em diferentes dias os seguintes testes: exercício incremental até a exaustão para a determinação do pico de consumo de oxigênio (VO2pico) e sua respectiva intensidade (IVO2pico); cinco a sete testes de carga constante para a determinação da MLSS e da PC; e um exercício até a exaustão na PC. A MLSS foi considerada com a maior intensidade de exercício onde a concentração de lactato não aumentou mais do que 1mM entre o 10º e o 30º min de exercício. Os valores individuais de potência (95, 100 e 110% IVO2pico) e seu respectivo tempo máximo de exercício (Tlim) foram ajustados a partir do modelo hiperbólico de dois parâmetros para a determinação da PC. Embora altamente correlacionadas (r = 0,99; p = 0,0001), a PC (313,5 ± 32,3W) foi significantemente maior do que a MLLS (287,0 ± 37,8W) (p = 0,0002). A diferença percentual da PC em relação à MLSS foi de 9,5 ± 3,1%. No exercício realizado na PC, embora tenha existido componente lento do VO2 (CL = 400,8 ± 267,0 ml.min-1), o VO2pico não foi alcançado (91,1 ± 3,3 %). Com base nesses resultados pode-se concluir que a PC e a MLSS identificam diferentes intensidades de exercício, mesmo em atletas com elevada aptidão aeróbia. Entretanto, o percentual da diferença entre a MLLS e PC (9%) indica que relação entre esses dois índices pode depender da aptidão aeróbia. Durante o exercício realizado até a exaustão na PC, o CL que é desenvolvido não permite que o VO2pico seja alcançado.

Utilização da relação potência-tempo até exaustão em testes de caminhada para avaliação da aptidão aeróbia

O objetivo do presente estudo foi avaliar a aptidão aeróbia em testes de caminhada com carga externa aplicada por meio da inclinação da esteira, a partir da relação não linear entre inclinação da esteira e tempo até a exaustão em velocidade fixa. Doze indivíduos do gênero masculino com 23,2 ± 2,7 anos de idade, 74,0 ± 7,9kg de massa corporal e 23,7 ± 2,5kg·(m²)-1 de IMC, realizaram duas etapas de testes de caminhada em esteira ergométrica com velocidade fixa de 5,5km·h-1 em todos os testes e sobrecarga de intensidade aplicada por meio de inclinação da esteira (%). A etapa 1 consistiu de três testes retangulares até a exaustão voluntária, nas intensidades de 18%, 20% e 22% de inclinação, para determinação dos parâmetros do modelo de potência crítica por dois modelos lineares e um hiperbólico. A etapa 2 consistiu na determinação da intensidade correspondente ao máximo estado estável de lactato sanguíneo (MEEL). ANOVA demonstrou que o modelo hiperbólico (15,4 ± 1,1%) resultou em estimativa significativamente menor que os outros dois modelos lineares inclinação-tempo-1 (16,0 ± 1,0%) e hiperbólico linearizado tempo-1-inclinação (15,9 ± 1,0%), porém, houve alta correlação entre os modelos. Os dois modelos lineares superestimaram a intensidade do MEEL (14,1 ± 1,4%), e o modelo hiperbólico, mesmo sem diferença estatística, apresentou fraca correlação, com baixa concordância em relação ao MEEL. Conclui-se que a relação inclinação-tempo até a exaustão, em testes de caminhada, não permitem a estimativa de intensidade de exercício suportável por longo período de tempo.

Exercício contínuo e intermitente: Efeitos do treinamento e do destreinamento sobre a gordura corporal de ratos obesos

Exercise training is often recommended in prevention and treatment of obesity. The present study was designed to compare the effects of intermittent and continuous exercise on weight loss and carcass composition in obese rats. Obese male Wistar rats (monosodium glutamate [MSG] administration, 4 mg/g of body weight every other day from birth to 14 days old) were used. After drug administration, the rats were separated into three groups: MSG-SED (sedentary), MSG-CONT (continuous, swimming, 45 min/day, 5 days/week, with and overload of 5% body weight for 12 weeks) and MSG-INT (intermittent, 15s swimming intermitted by 15s rest, during 45 min, 5 days/week, with and overload of 15% body weight for 12 weeks). Rats of the same age and strain, administered with saline were used as control (SAL), and subdivided into three groups: SAL-SED, SAL-CONT and SAL-INT. The animals were evaluated at the 10 weeks of training and 8 weeks of its interruption. MSG rats showed higher carcass fat as well as weight and cell size in epididymal adipose tissue than SAL rats, indicting the efficacy of the drug in producing obesity. Intermittent training protocol led to a reduction in blood lactate accumulation during acute exercise and both protocols reduced body weight gain during the experiment in MSG rats. After 8 weeks of training interruption no differences were observed among groups in the examined parameters. Only intermittent exercise training improved aerobic fitness but both protocols were similarly efficient in determining weight loss. However, the effects were transitory, since they disappeared after detraining.