Limiar de lactato em exercício resistido

Lactate thresholds (LT) during activities such as running, cycling, rowing, and swimming have been the subject of many studies for the past several decades. However, little is known about the LT parameter during endurance exercises. The purpose of this study was to assess and compare relative and absolute values of LT relative to individual maximal workload during leg-press (LP) and elbow flexion (EF) exercises for both trained (T) and untrained (U) male participants. There was no difference between the relative LT for the four groups (LP-T = 32.22 4.40%; LP-U = 28.0 6.32%; EF-T = 32.22 6.66%; RD-U = 28.88 3.33%). On the other hand, the absolute values for both trained groups (LP-T = 173.0 51.97 kg and EF-T = 18.73 4.13 kg) were significantly different (p< .05) compared to the untrained groups (LP-U = 84.10 18.78 kg; EF-U = 10.81 1.27 kg). The results suggest that the LT for LP and EF exercises are similar only when relative workload is considered.Existem muitas pesquisas sobre o limiar do lactato (LL) durante atividades como corrida, ciclismo, remo e natação, mas não existem informações sobre este parâmetro durante exercícios resistidos. O objetivo do presente estudo foi comparar valores relativos e absolutos do LL, em relação à carga máxima, nos exercícios leg-press (LP) e rosca direta (RD), de homens treinados (T) e não-treinados (NT). Os valores relativos do LL dos 4 grupos (LP-T = 32,22 4,40%; LP-NT = 28,0 6,32%; RD-T = 32,22 6,66%; RD-NT = 28,88 3,33%) não foram diferentes. Os resultados em valores absolutos (173,0 51,97 kg para LP-T , 84,10 18,78 kg para LP-NT, 18,73 4,13 kg para RD-T e 10,81 1,27 kg para RD-NT) foram diferentes (

Eletromyography of abdominal muscles in different physical exercises: An update protocol for systematic review and meta-analysis

Background:The abdominal muscles are extremely important because they are directly involved in the functions of support, containment of viscera, and help in the process of expiration, defecation, urination, vomiting, and also at the time of childbirth. Many exercises and equipment are used to strengthen the abdominal muscles, and the workouts are proposed for a variety of purposes, such as preventing and rehabilitating low back pain, improving sports performance, achieving aesthetic standards, among others. Exercises that potentiate the electromyographic activity promote a greater recruitment of muscle fibers and are more effective to improve or maintain of the force. The electromyographic activity analysis allows us to reflect on the quality of the exercises proposed, consequently, to choose and order the exercises properly in a training session.Methods:Our systematic review protocol will developed following the reporting items for the systematic review. To identify relevant studies, we sought articles on the following bases: MEDLINE, PubMed, Europubmed, SciELO, Physiotherapy Evidences Data Base (PEDro), Cochrane, and Google Scholar. The methodological quality of the studies included in the review will evaluated using a checklist and quality assessment. For intervention studies, risk of bias will estimated using the Cochrane Collaboration tool.Results:The results of this study will show the electromyographic activation of the abdomen in the different types of exercises.Conclusion:Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal.Systematic review registration:PROSPERO CRD42018086172.Univ Fed Uberlandia, Inst Biomed Sci, Electromyog Lab, Uberlandia, MG, BrazilUniv Fed Uberlandia, Lab Expt Med, Uberlandia, MG, BrazilUniv Fed Goias, Dept Biol Sci, Catalao, BrazilUNIPAC Coll Uberlandia, Uberlandia, MG, BrazilUniv Fed Uberlandia, Coll Phys Educ, Uberlandia, MG, BrazilAtenas Coll, Morphofunct Dept, Paracatu, BrazilUniv Fed Sao Paulo, Dept Biosci, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Biosci, Sao Paulo, BrazilWeb of Scienc

Análise sigmoidal da curva da lactatemia em teste incremental: novos horizontes

CHAPTER II: The aim of the present study was to compare five methods of lactate thre-shold (LT) identification in resistance exercise (RE). Eight healthy males, non se-dentary (25.6 ± 6.61 years old, 78.6 ± 3.48 kg of body weight) performed an in-cremental test in leg press resistance exercise until the voluntary exhaustion. The initial workload was 10% of one maximal repetition (1RM), with 5% of increment each stage. The stages were consisted of 1 min with 1 min of rest between them. Blood samples of 25 ml, were collected for blood lactate concentration ([Lac]) anal-ysis. Five methods for LT intensity identification in RE were compared with each other: Lactate quotient (LQ); fixed point of 4 mM (OBLA); visual inspection (VI); 1mM of [Lac] above the baseline (OPLA); and the novel method, proposed by our study, consisted in 20% of the maximum [Lac] during the incremental test (X20). It was possible to identify the LT using all the five methods. However, the ANOVA showed significant difference between the OBLA and all the methods, and this suggest that this method overestimates the exercise intensity at the LT. Based in our results, we concluded that the X20 was not statistically different from the QL, IV and OPLA. Morever the incremental protocol with 1 minute of exercise bout, 1 minute of rest between the bouts and increment of 5% of the 1RM, was valid for LT identification using all the methods. CHAPTER III: This study was designed to analyse the curve of lactate in response to in-cremental exercise as a sigmoid.To this end, 25 male volunteers, aged 23.2 ± 2.1 years old, 71.6 ± 6 1 kg body mass, 180 ± 10 cm tall, underwent an incremental test to determine the X50; they also underwent submaximal constant load tests to determine maximal lactate steady state (MLSS). The exercise intensity in Watts at X50 (W-X50) was determined based on the dependence between the concentra-tion of lactate and exercise intensity, which were analyzed in a sigmoid function (Boltzmann function). The results showed that the intensities of W-X50 (162.16 ± 33.59 Watts) and W-MLSS (157.80 ± 31.55 Watts) were not significantly different at p 0.05) at 22°C (181.4±30,1W and 180.0±32.1W, respectively) and at 40 °C (155.8±27.0W and 148.1±32.5W, respectively), however they were different (p<0.05) when analysing between different environments. Therefore, the W-X50 can be used to valid and sensible method to predict the W-MLSS and assessment of submaximal aerobic performance in thermoneutral and hyperthermic environ-ments.Universidade Federal de UberlândiaDoutor em Genética e BioquímicaO objetivo do presente estudo foi comparar 5 métodos de identificação do limiar de lactato (LL) em exercício resistido (ER). Oito homens fisicamente ativos com idade média 25.6 ± 6.61 anos e massa corporal média 78.6 ± 3.48 kg, realizaram um teste incremental até a exaustão voluntária no exercício Leg-Press. A carga inicial consistiu em 10% da máxima (1RM), com 5% de acréscimo em cada estágio. Os estágios consistiram de 1 minuto de exercício com 1 minuto de intervalo entre eles. Amostras de 25uL foram coletadas para análise da lactatemia. Os Cinco métodos utilizados para determinar o LL foram: Quociente de Lactato (QL); Ponto fixo de 4mM (OBLA); Inspeção Visual (IV); 1mM [lactato[ acima da linha de Base (OPLA) e o X20, um novo método proposto pelo nosso laboratório. Foi possível identificar o LL pelos 5 métodos em todos voluntários. O ANOVA demonstrou significativa diferença entre o método OBLA com os demais (verificado pos hoc de TUCKEY), sugerindo que o OBLA superestime a intensidade do LL. Baseado na não diferença entre a intensidade do X20 e as intensidades do QL, OPLA e IV, podemos concluir este novo método pode ser utilizado para determinação da intensidade do LL em exercício resistido

Efeito de diferentes intervalos entre as tentativas do teste de 1-RM no desempenho de força máxima em mulheres

O teste de uma repetição máxima (1-RM) é frequentemente aplicado para medir a força de um indivíduo em um determinado exercício. O objetivo do presente estudo foi comparar o efeito de diferentes intervalos entre as tentativas do teste de 1-RM no desempenho de força máxima em mulheres no exercício leg press 45°. Para tanto, 12 voluntárias (19 ± 1 ano) praticantes de exercícios resistidos há no mínimo seis meses foram submetidas a quatro sessões de testes, alternadas por no mínimo 48 horas de repouso. Os intervalos de recuperação entre as tentativas do teste de 1-RM foram de 30, 45, 60 e 180 segundos, sendo que a ordem de execução foi definida aleatoriamente. Para identificação da diferença entre os intervalos propostos foi aplicada a análise de variância ANOVA One-way (p &lt; .05). Os resultados não revelaram diferenças significativas no desempenho de força máxima em mulheres, quando comparados os valores médios de teste obtidos em cada um dos intervalos propostos. Esses achados indicam que para a medida de força máxima no exercício leg press 45°, intervalos menores do que um minuto (30 - 45 segundos) podem ser utilizados com a mesma precisão que intervalos maiores, garantindo maior economia de tempo para a aplicação do teste de 1-RM.<br /

The nares as a CA-MRSA reservoir in the healthy elderly

Abstract:INTRODUCTION:The frequency of methicillin-resistant Staphylococcus aureus (MRSA) has increased in the community. This study evaluated the prevalence of MRSA and community-acquired (CA)-MRSA in 120 healthy elderly.METHODS:The MRSA were evaluated for the presence of the IS256, mecA, agr, icaA, icaD, fnbB , and pvl genes with PCR. Results: Frequency of S. aureus and MRSA colonization was 17.8% and 19%, respectively. CA-MRSA isolate showed SCC mec IV, fnbB+ , and icaD+ .CONCLUSIONS:CA-MRSA was detected, with genotype determined as SCC mec type IV/IS256/ fnbB+ / icaA / icaD+ / bbp-/agr2 / bap / pvl, characterizing this population as a possible reservoir of this organism in the community

Análise de limiar anaeróbica no exercício resistido com cargas crescentes em atleta portador de poliomielite, suplementado com creatina e maltodextrina

Avaliar a cinética da lactatemia no exercício supino reto em portadores de poliomielite suplementados com creatina. Oito voluntários do gênero masculino com 37±7 anos e 67±6,8 Kg aparentemente saudáveis passaram por duas fases de testes: a) medição da carga máxima (CM); e teste de cargas crescentes no supino reto iniciando a 10% da CM com incremento de 10% a cada estágio b) repetição dos procedimentos da primeira fase após a suplementação. O tempo para cada estágio foi de 45 segundos, com 2 minutos de descanso. No período de descanso coletou-se o sangue. Os voluntários foram divididos em grupos (n=4), grupo suplementados com creatina + maltodextrina (GMC) e grupo suplementado com maltodextrina (GM). A dosagem de creatina foi 0,3 g/kg-1 de peso corporal. O limiar de lactato se manteve em 30% da CM depois da suplementação. Não houve diferença entre as concentrações de lactato no teste antes e após a suplementação no grupo GM (p=0.031 e r=0.99), e no grupo GMC (p=0.0045 e r=0.99). O limiar de lactato dos dois grupos após a suplementação não foram diferentes entre eles (p=0.031 e r=0.99). Entretanto observou-se que a suplementação para o grupo GMC aumentou 8,70% da CM (p< 0,05) e um estagio a mais. A cinética do lactato foi semelhante entre os dois grupos. Os resultados demonstram aumento de ganho de força e resistência, mas sem alteração no limiar de lactato pela suplementação de creatina e maltodextrina. (*) O presente trabalho atende às �Normas de Realização de Pesquisa em Seres Humanos�, Resolução n.º 196/196 do Conselho Nacional de Saúde. de 10/10/96 (BRASIL, 1996), tendo sido submetido e aprovado pelo Comitê de Ética em Pesquisa Envolvendo Seres Humanos, da Universidade Federal de Uberlândia, parecer n.º 009/2003

Quality of life and impact of physical activity time in the health of elderly

Objective: This study aimed to evaluate the quality of life, through the “Medical Outcomes Study 36 - Item Short - Form Health Survey” (SF-36) questionnaire, of a group of elderly involved in physical activities scheduled and the impact of physical activity time. Methods: We assessed 143 elderly engaged in physical activity programmed by Universidade Federal de Uberlândia. As a data collection tool, we used the SF-36 and a sociodemographic questionnaire, applied at the time of the interview. Statistical analysis was performed using Kruskal-Wallis, for analysis between domains, and Mann-Whitney test, to verify the relationship between health status and physical activity level. Results: The average age was 70.5 years. The mean score for the SF-36 of the elderly people who participated in the research was 73.3. The best result was in the Social Aspects domain (81.7), followed by Mental Health (78.9). Approximately 76% had at least 150 minutes of physical activity per week, being classified as a more active population. Most (70.6%) of the elderly had a good perception of their general health. There was statistical difference in the General Health domain among groups that performed physical activity for a period of less than one year and those who have been engaging in regular physical activity for over 10 years. Conclusions: The Social Function and Mental Health domains had the highest scores, with significant documentation of a better general health in the group that have practiced consecutive physical activity for over ten years