VO2 and velocity in rct during continuous incremental treadmill test of uphill and dowhill

The etiology of the drift in VO2 in the respiratory compensatory threshold (RCT) during downhill running is unclear. It was investigated the velocities (VRCT) and VO2 in RCT (RCTVO2) in three different inclinations in the continuous incremental treadmill test (Tt). Eight sedentary women volunteered (24±2 years old) to undergo 10% downhill (DT), 10% uphill (UT) and near-level (NL) in Tt to exhaustion to determine the RCTVO2 and VRCT and peak VO2 on different days and were randomly allocated. VCO2 was examined as function of VE under the assumption that the RCT corresponds to the break point in the VE-VCO2 relationship. Peak VO2 was taken as the average of the highest five consecutive breaths attained in the individual work rates for the steps test in three different inclinations. It was used one-way ANOVA (Tukey’s post hoc test) to compare the differences. Statistical significance was set at P≤ 0.05. Peak VO2 was 34.62±4.20 mL.kg.min-1, 33.14±3.60 mL.kg.min-1 and 32.74±2.66 mL.kg.min-1 for NL, UT and DT respectively (P\u3e0.05). RCTVO2 was NL = 29.14±7.95 mL.kg.min-1, UT = 30.10±4.53 mL.kg.min-1 and DT = 29.70±3.00 mL.kg.min-1 (P\u3e0.05). VRCT was 10.38±1.92 km/h, 8.25±0.89 km/h and 12.88±1.46 km/h for NL, UT and DT respectively (P\u3c0.01). Tukey’s post hoc test find the following differences between NL vs UT (P\u3c0.05), NL vs DT (P\u3c0.05) and UT vs DT (P\u3c0.01). The drift in VO2 in the respiratory compensatory threshold during the three bouts appears unrelated biomechanical factors possibly due to a decoupling of neuromuscular and metabolic responses under the status of training

Determination of blood glucose threshold in boys: descriptive analysis

The blood glucose threshold (GT) has been used for the assessment of the aerobic capacity for trained individuals in replace of the blood lactate and ventilatory parameters for anaerobic threshold determination. But, there are no studies with boys. The purpose of this study was to measure the intensity corresponding to the GT in a group of boys. Eight boys (11±1.12 years; 38±6.93 kg; 1.44±0.09 m; 18±1.79 kg/m2) performed a graded maximal exercise test on a cycloergometer to determine the Watts peak (WP), heart rate maximum (HRmax), Watts at GT (GTw) and heart rate at GT (GThr). The initial intensity was 15 Watts with 15 Watts of increment every three minutes. The results showed (M±SD) that the WP was 128±12; HRmax: 193±10.64; GTw: 96±19.47; GThr: 161±20.08. The GT was at 75±11.97% of the WP. The results were similar to those reported in studies with children using other physiological variables for anaerobic threshold determination. In conclusion, the study shows that GT is possible to be determined in boys during incremental test

Airflow-Restricting Mask Reduces Acute Performance in Resistance Exercise

Background: The aim of this study was to compare the number of repetitions to volitional failure, the blood lactate concentration, and the perceived exertion to resistance training with and without an airflow-restricting mask. Methods: Eight participants participated in a randomized, counterbalanced, crossover study. Participants were assigned to an airflow-restricting mask group (MASK) or a control group (CONT) and completed five sets of chest presses and parallel squats until failure at 75% one-repetition-maximum test (1RM) with 60 s of rest between sets. Ratings of perceived exertion (RPEs), blood lactate concentrations (Lac(-)), and total repetitions were taken after the training session. Results: MASK total repetitions were lower than those of the CONT, and (Lac(-)) and MASK RPEs were higher than those of the CONT in both exercises. Conclusions: We conclude that an airflow-restricting mask in combination with resistance training increase perceptions of exertion and decrease muscular performance and lactate concentrations when compared to resistance training without this accessory. This evidence shows that the airflow-restricting mask may change the central nervous system and stop the exercise beforehand to prevent some biological damage.Univ Fed Sao Paulo, Grp Studies & Res Exercise Physiol GEPEFEX, BR-11015020 Sao Paulo, BrazilCruzeiro Univ, Inst Phys Act Sci & Sport, BR-03342000 Sao Paulo, BrazilUniv Fed Sao Paulo, Grp Studies & Res Exercise Physiol GEPEFEX, Postgrad Program Human Movement Sci & Rehabiltat, BR-11015020 Sao Paulo, BrazilGroup of Studies and Research in Exercise Physiology (GEPEFEX), Universidade Federal de São Paulo (UNIFESP), São Paulo 11.015-020, BrazilPostgraduate Program in Human Movement Sciences and Rehabilitation, Group of Studies and Research in Exercise Physiology (GEPEFEX), Universidade Federal de São Paulo (UNIFESP), São PauloWeb of Scienc

Single resistance training session leads to muscle damage without isometric strength decrease

Here we demonstrated that a single resistance exercise session causes muscle damage, delayed onset muscle soreness (DOMS), higher creatine kinase (CK) and lactate dehydrogenase (LDH) activity, and increased IL-6 concentration without changes in muscle strength. Sixteen healthy untrained subjects performed five exercises consisting of three sets of 10 maximum repetitions for each exercise and 1 minute rest period between sets and exercises. Blood samples were taken after 30 minutes, 24, 48 and 72 hours and before exercise. Muscular performance was assessed by maximum isometric strength (MIS) before, 24h, 48h and 72h exercise session. We have concluded that the single resistance exercise session, performed on this study, led to muscle damage and this variable cannot be evaluated through maximal isometric strength. Among those markers, CK was more sensitive to muscle damage. This information might be important for adequate recovery between training sessions

Resistance training with slow speed of movement is better for hypertrophy and muscle strength gains than fast speed of movement.

Repetition speed is an important variable during resistance training. However, the effects of different speeds on the muscular strength and hypertrophy in isotonic resistance training are not clear. The study compared fast speed with slow speed of isotonic resistance training on muscular strength and hypertrophy in well-trained adults. Twelve healthy adults were randomly assigned into two groups: fast speed (FS) and low speed (SS). Muscle hypertrophy was measured by an ultrasound examination of the cross-sectional area of the brachial biceps muscle. Muscular strength was verified by 1 RM test. To check the possible differences in strength and hypertrophy between pre and post training and between groups there were compared by two-way ANOVA for repeated measurements and the effect size (ES) was calculated. Improvement in the cross-sectional area (P=0.019) and muscular strength (P=0.021) in the SS group between pre and post training was verified. The SS group had bigger effect sizes than FS group for hypertrophy and strength from pre to post training. SS training was more effective to improve hypertrophy and muscle strength in well-trained adults.Univ Fed Sao Paulo, Grp Studies & Res Exercise Physiol, Santos, SP, BrazilPraia Grande Coll, Grp Studies Sci Phys Educ, Praia Grande, SP, BrazilUniv Fed Sao Paulo, Dept Human Movement Sci, Santos, SP, BrazilUniv Fed Sao Paulo, Grp Studies & Res Exercise Physiol, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Human Movement Sci, Santos, SP, BrazilWeb of Scienc

Métodos alternativos para estimar a velocidade da máxima fase estável de lactato em adultos jovens fisicamente ativos

The aim of this study was to compare the velocities found in the protocols used to measure the indirect individual anaerobic threshold (IATind), glucose threshold (GT) and critical velocity (CV) with the gold standard, the maximum lactate steady state (MLSS) protocol. Fourteen physically active young adults (23±3.1 years; 72±10.97 kg; 176±7 cm; 21±5.36% body fat) performed a 3000-m track running test to determine IATind using the prediction equation and an incremental test on a treadmill to determine GT. The CV was identified by linear regression of the distance-time relationship based on 3000-m and 500-m running performance. The MLSS was identified using two to five tests on different days to identify the intensity at which there was no increase in blood lactate concentration greater than 1 mmol/L between the 10th and 30th minute. A significant difference was observed between mean CV and MLSS (P≤0.05) and there was a high correlation between MLSS and IATind (R2=0.82; P≤0.01) and between MLSS and GT (R2=0.72; P≤0.01). The Bland-Altman method showed agreement between MLSS and IATind [mean difference -0.24 (confidence interval -1.72 to 1.24) km/h] and between MLSS and GT [0.21 (-1.26 to 1.29) km/h]. We conclude that the IATind and GT can predict MLSS velocity with good accuracy, thus making the identification of MLSS practical and efficient to prescribe adequate intensities of aerobic exercise.O objetivo do presente estudo foi comparar as velocidades encontradas nos protocolos de Limiar Anaeróbio Individual Indireto (LAIind), Limiar Glicêmico (LG) e Velocidade Crítica (VC) com o padrão ouro, o protocolo de identificação da máxima fase estável do lactato (MFEL). Participaram 14 adultos jovens fisicamente ativos (23±3,1 anos; 72±10,97 kg; 1,76±0,07 m; 21±5,36 % gordura corporal) que realizaram um teste de 3000m em pista para determinar o LAIind através de equação de predição; teste incremental em esteira ergométrica para determinação do LG; a VC foi identificada por regressão linear através da relação distância-tempo com base no desempenho em corridas nas distâncias de 3.000m e 500m; a MFEL foi identificada utilizando de dois a cinco testes em dias distintos até encontrar a intensidade onde não houve aumento da concentração de lactato sanguíneo maior que 1 mmol.L-1 entre os minutos 10 e 30. Houve diferença estatística entre os valores médios da VC e a MFEL (P≤0,05), elevada correlação entre MFEL e LAIind (R2=0,82; P≤0.01) e MFEL e LG (R2=0,72; P≤0.01). Através do método Bland-Altman foram encontradas as concordâncias entre MFEL e LAIind [diferença média -0,24 (intervalo de confiança -1,72 a 1,24) km/h] e MFEL e LG [0,21 (-1,26 a 1,29) km/h]. Concluímos que o LAIind e o LG são testes que podem predizer com boa precisão a velocidade da MFEL, tornando sua identificação prática e eficiente para prescrição de intensidades adequadas para o treinamento aeróbio.Universidade Federal de São Paulo (UNIFESP)Faculdade Anhanguera de BauruUniversidade Federal de São Paulo (UNIFESP) Departamento de Ciências do Movimento HumanoUNIFESP, Depto. de Ciências do Movimento HumanoSciEL

A extensão universitária frente ao isolamento social imposto pela COVID-19 / University extension front of the social isolation imposed by COVID-19

A emergência de uma nova pandemia não é uma questão de “se”, mas de “quando” irá acontecer. Atualmente, estamos diante da mais importante crise de saúde pública mundial, a pandemia do novo coronavírus. A Universidade é uma instituição criada para atender às necessidades sociais e uma das estratégias para realizar esse dever é através de ações de extensão universitária. Mas como realizar extensão universitária frente ao isolamento social imposto pelo COVID-19? Durante a pandemia a Universidade ganhou destaque em ações extensionistas, especialmente na disseminação e construção correta do conhecimento sobre SARS-CoV-2 e COVID-19, em ações que objetivam o desenvolvimento e confecção de insumos para proteção individual e coletiva, distribuídos para hospitais, profissionais de saúde e em comunidades carentes, e atividades de educação e cultura explorando novos recursos em plataformas digitais. Acreditamos no poder transformador da Universidade e no seu compromisso em reduzir impactos sociais através da extensão e que no futuro próximo a extensão deve ser enquadrada no mundo pós-pandemia

Commentaries on viewpoint : physiology and fast marathons

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Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio