Reliability of Anaerobic Contributions during a Single Exhaustive Knee-extensor Exercise.

The total anaerobic contribution (AC[La-]+PCr) is a valid and reliable methodology. However, the active muscle mass plays an important role in the AC[La-]+PCr determination, which might influence its reliability. Thus, this study aimed to investigate the effects of two exhaustive intensities on the reliability of the AC[La-]+PCr during a one-legged knee extension (1L-KE) exercise. Thirteen physically active males were submitted to a graded exercise to determine the peak power output (PPO) in the 1L-KE. Then, two constant-load exercises were conducted to task failure at 100% (TTF100) and 110% (TTF110) of PPO, and the exercises were repeated on a third day. The blood lactate accumulation and the oxygen uptake after exercise were used to estimate the anaerobic lactic and alactic contributions, respectively. Higher values of AC[La-]+PCr were found after the TTF100 compared to TTF110 (p=0.042). In addition, no significant differences (p=0.432), low systematic error (80.9 mL), and a significant ICC (0.71; p=0.004) were found for AC[La-]+PCr in the TTF100. However, an elevated coefficient of variation was found (13.7%). In conclusion, we suggest the use of the exhaustive efforts performed at 100% of the PPO with the 1L-KE model, but its elevated individual variability must be carefully considered in future studies.

Acute physiological responses to "recovery intermittent hypoxia" in hiit / Respuestas agudas a la "hipoxia intermitente de recuperación" en el hiit / Respostas fisiológicas agudas à "hipóxia intermitente de recuperação" no hiit

ABSTRACT Introduction: Traditional intermittent hypoxia training improves sport performance after short periods of exposure, but acute exposure to intermittent hypoxia leads to decreased training intensity and technical quality. The solution to overcome these negative effects may be to perform efforts in normoxia and the intervals between efforts in hypoxia, maintaining the quality of training and the benefits of hypoxia. Objective: This study aimed to evaluate the acute physiological responses to hypoxia exposure during recovery between high intensity efforts. Materials and methods: Randomized, one-blind, placebo-controlled study. Sixteen men performed a graded exercise test to determine their maximal intensity and two sessions of high-intensity interval training. The training intervals could be in hypoxia (HRT), FIO2: 0.136 or normoxia (NRT), FIO2: 0.209. During the two-minute interval between the ten one-minute efforts, peripheral oxygen saturation (SpO2), heart rate (HR), blood lactate ([La]), blood glucose ([Glu]) were constantly measured. Results: There were differences in HR (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p < 0.01) and SpO2 (TRN = 96.9 ± 1.0%; TRH = 86.2 ± 3.5%, p < 0.01). No differences in [La] and [Glu] TRN (4.4 ± 1.7 mmol.l-1; 3.9 ± 0.5 mmol.l-1) and TRH (5.2 ± 2.0 mmol.l-1; 4.0 ± 0.8 mmol.l-1, p = 0.17). Conclusion: The possibility of including hypoxia only in the recovery intervals as an additional stimulus to the training, without decreasing the quality of the training, was evidenced. Level of Evidence II; Randomized Clinical Trial of Minor Quality.

RESUMEN Introducción: El entrenamiento tradicional en hipoxia intermitente mejora el rendimiento deportivo tras cortos periodos de exposición, sin embargo, la exposición aguda a la hipoxia intermitente conduce a una disminución de la intensidad del entrenamiento y de la calidad técnica. La solución para superar estos efectos negativos puede ser realizar los esfuerzos en normoxia y los intervalos entre esfuerzos en hipoxia, manteniendo la calidad del entrenamiento y los beneficios de la hipoxia. Objetivo: Este estudio pretendía evaluar las respuestas fisiológicas agudas a la exposición a la hipoxia durante la recuperación entre esfuerzos de alta intensidad. Materiales y métodos: Estudio aleatorizado, a ciegas y controlado con placebo. Dieciséis hombres realizaron una prueba de ejercicio graduado para determinar su intensidad máxima y dos sesiones de entrenamiento por intervalos de alta intensidad. Los intervalos de entrenamiento podían ser en hipoxia (HRT), FIO2: 0,136 o normoxia (NRT), FIO2: 0,209. Durante el intervalo de dos minutos entre los diez esfuerzos de un minuto, se midieron constantemente la saturación periférica de oxígeno (SpO2), la frecuencia cardiaca (FC), el lactato en sangre ([La]) y la glucemia ([Glu]). Resultados: Hubo diferencias en la FC (TRN = 120 ± 14 lpm; TRH = 129 ± 13 lpm, p < 0,01) y la SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p < 0,01). No hubo diferencias en [La] y [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) y TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusión: Se evidenció la posibilidad de incluir hipoxia sólo en los intervalos de recuperación como estímulo adicional al entrenamiento sin disminuir la calidad del mismo. Nivel de Evidencia II; Ensayo Clínico Aleatorizado de Baja Calidad.

RESUMO Introdução: O treinamento de hipóxia intermitente tradicional melhora o desempenho esportivo após curtos períodos de exposição, porém a exposição aguda à hipóxia intermitente leva à diminuição da intensidade do treinamento e da qualidade técnica. A solução para superar esses efeitos negativos pode ser realizar esforços em normóxia e os intervalos entre os esforços em hipóxia, mantendo a qualidade do treinamento e os benefícios da hipóxia. Objetivo: Este estudo teve como objetivo avaliar as respostas fisiológicas agudas à exposição de hipóxia durante a recuperação entre esforços de alta intensidade. Materiais e métodos: Estudo aleatório e one-blinded, com efeito placebo controlado. Dezesseis homens realizaram um teste de exercício graduado para determinar sua intensidade máxima e duas sessões de treinamento intervalado de alta intensidade. Os intervalos de treinamento podem ser em hipóxia (TRH), FIO2: 0,136 ou normóxia (TRN), FIO2: 0,209. Durante os dois minutos de intervalo entre os dez esforços de um minuto, foram medidos constantemente a saturação periférica de oxigênio (SpO2), frequência cardíaca (FC), lactato sanguíneo ([La]), glicemia ([Glu]). Resultados: Houve diferenças na FC (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p <0,01) e SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p <0,01). Sem diferenças em [La] e [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) e TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusão: Evidenciou-se a possibilidade de incluir a hipóxia apenas nos intervalos de recuperação como um estímulo adicional ao treinamento, sem diminuir a qualidade do treinamento. Nível de Evidência II; Estudo Clínico Randomizado de Menor Qualidade.

Effects of Moderate-Intensity Training Under Cyclic Hypoxia on Cardiorespiratory Fitness and Hematological Parameters in People Recovered From COVID-19: The AEROBICOVID Study.

BACKGROUND: Recent studies have indicated that people who live at altitude have a lower incidence of coronavirus disease (COVID-19) and lesser severity in infection cases. HYPOTHESIS: Hypoxia exposure could lead to health benefits, and it could be used in the recovery process as an additional stimulus to physical training to improve cardiorespiratory fitness (CRF). STUDY DESIGN: Randomized controlled clinical trial. LEVEL OF EVIDENCE: Level 2. METHODS: The 43 participants, aged 30 to 69 years, were divided into control group (CG, n = 18) and 2 training groups: normoxia (NG, n = 9) and hypoxia (HG, n = 16). Before and after the intervention were evaluated the lactate threshold 2 (L2), peak oxygen uptake (VO2peak), and a blood sample was collected at rest to evaluate hematological adaptation. Both groups performed an 8-week moderate-intensity physical training on a bike. The HG were trained under normobaric hypoxic conditions (fractional inspired oxygen [FiO2] = 13.5%). RESULTS: The 8-week intervention promoted a similar improvement in CRF of people recovered from COVID-19 in the HG (L2 = 34.6%; VO2peak = 16.3%; VO2peak intensity = 24.6%) and NG (L2 = 42.6%; VO2peak = 16.7%; VO2peak intensity = 36.9%). Only the HG presented differences in hematological variables (erythropoietin = 191.7%; reticulocytes = -32.4%; off-score = 28.2%) in comparison with the baseline. CONCLUSION: The results of the present study provide evidence that moderate-intensity training in normoxia or hypoxia promoted similar benefits in CRF of people recovered from COVID-19. Furthermore, the hypoxia offered an additional stimulus to training promoting erythropoietin increase and hematological stimulation. CLINICAL RELEVANCE: The present exercise protocol can be used for the rehabilitation of people recovered from COVID-19, with persistent low CRF. In addition, this is the first study demonstrating that physical training combined with hypoxia, as well as improving CRF, promotes greater hematological stimulation in people recovered from COVID-19.

Incremental and decremental cardiopulmonary exercise testing protocols produce similar maximum oxygen uptake in athletes.

The aim of the study was to evaluate and compare the maximal oxygen uptake ([Formula: see text]O2max) achieved during incremental and decremental protocols in highly trained athletes. Nineteen moderate trained runners and rowers completed, on separate days, (i) an initial incremental [Formula: see text]O2max test (INC) on a treadmill, followed by a verification phase (VER); (ii) a familiarization of a decremental test (DEC); (iii) a tailored DEC; (iv) a test with decremental and incremental phases (DEC-INC); (v) and a repeated incremental test (INCF). During each test [Formula: see text]O2, carbon dioxide production, ventilation, heart and breath rates and ratings of perceived exertion were measured. No differences were observed in [Formula: see text]O2max between INC (61.3 ± 5.2 ml kg-1 min-1) and DEC (61.1 ± 5.1 ml kg-1 min-1; average difference of ~ 11.58 ml min-1; p = 0.831), between INC and DEC-INC (60.9 ± 5.3 ml kg-1 min-1; average difference of ~ 4.8 ml min-1; p = 0.942) or between INC and INCF (60.7 ± 4.4 ml kg-1 min-1; p = 0.394). [Formula: see text]O2max during VER (59.8 ± 5.1 ml kg-1 min-1) was 1.50 ± 2.20 ml kg-1 min-1 lower (~ 2.45%; p = 0.008) compared with values measured during INC. The typical error in the test-to-test changes for evaluating [Formula: see text]O2max over the five tests was 2.4 ml kg-1 min-1 (95% CI 1.4-3.4 ml kg-1 min-1). Decremental tests do not elicit higher [Formula: see text]O2max than incremental tests in trained runners and rowers, suggesting that a plateau in [Formula: see text]O2 during the classic incremental and verification tests represents the maximum ceiling of aerobic power.

Corrigendum: Proposal of a Conditioning Activity Model on Sprint Swimming Performance.

[This corrects the article DOI: 10.3389/fphys.2020.580711.].

Proposal of a Conditioning Activity Model on Sprint Swimming Performance.

This study aimed to propose a conditioning activity (CA) model to stimulate improvement on neuromuscular responses, mechanical parameters and for the 50-m freestyle swimming. Thirteen male swimmers (19 ± 3 years and performances of 77% in relation to World Championship records) performed four CA protocols followed by a maximum performance in the 50-m freestyle. In the first protocol (P1) swimmers performed a standard warm-up (∼15 min); in the second protocol (P2) lunges (3 × 85% of the one-repetition maximum); in the third (P3) pull-ups (3 maximum repetitions) and box jumps 40 cm high and 60 cm deep (1 × 5 with 10% of the corporal weight); and in the fourth protocol (P4) a combination of exercises from the second and third protocols. CA protocols had no effect on the standard warm-up. However, P2 performance (27.01 ± 1.25 s) was similar to P1 (27.01 ± 1.18 s) and presented higher positive effects in mechanical parameters for the swim start performance in comparison to other protocols, contributing to improvements in the 50-m freestyle. In addition, turnaround time also had a negative effect, mainly in P3 (3.12 ± 0.28 s), signaling the improvement of this variable in all protocols (P1: 3.30 ± 0.38 s; P2: 3.17 ± 0.30 s; P4: 3.17 ± 0.34 s). P2 (after: 80 ± 11%; before: 82.7 ± 9.9%) and P3 (after: 82.7 ± 9.9%; before: 85.1 ± 9.7%) presented a possible positive effect on the percentage of voluntary activation in relation to P1 (after: 79.3 ± 10.7%; before: 76.3 ± 12%). In conclusion, the proposed conditioning activity protocols were not efficient for performance improvement in the 50-m freestyle compared to the standard model and seem to specifically influence each phase of the event.

Correction to: Beta alanine supplementation effects on metabolic contribution and swimming performance.

An amendment to this paper has been published and can be accessed via the original article.

Beta alanine supplementation effects on metabolic contribution and swimming performance.

BACKGROUND: Investigations of ß-alanine supplementation shows effects on metabolic (aerobic and anaerobic) participation and performance on swimming by a possible blood acidosis buffering. Considering this background, the objective of the present study was to analyze the effects of ß-alanine supplementation on metabolic contribution and performance during 400-m swim. METHODS: Thirteen competitive swimmers underwent a 6-week, double-blind placebo-controlled study, ingesting 4.8 g.day- 1 of ß-alanine or placebo. Before and after the supplementation period, the total anaerobic contribution (TAn) and 30-s all-out tethered swimming effort (30TS) were assessed. Anaerobic alactic (AnAl) and lactic energy (AnLa) was assumed as the fast component of excess post-exercise oxygen consumption and net blood lactate accumulation during exercise (∆[La-]), respectively. Aerobic contribution (Aer) was determined by the difference between total energy demand and TAn. In addition to conventional statistical analysis (Repeated measures ANOVA; p > 0.05), a Bayesian repeated measures ANOVA was used to evidence the effect probability (BFincl). RESULTS: No differences and effects were found between groups, indicating no supplementation effects. Repeated measures ANOVA, with confirmation of effect, was indicate reduce in ∆Lactate (p: 0.001; BFincl: 25.02); absolute AnLa (p: 0.002; BFincl: 12.61), fatigue index (p > 0.001; BFincl: 63.25) and total anaerobic participation (p: 0.008; BFincl: 4.89). CONCLUSIONS: Thus, the results demonstrated that all changes presented were evidenced as a result of exposure to the training period and ß-alanine supplementation doesn't affect metabolic contribution and performance during 400-m freestyle.

Determination of individual glucose threshold using pharmacy portable blood glucose meter / Determinação do limiar glicêmico individual com o uso de glicosímetro portátil de farmácia / Determinación del umbral glucémico individual con el uso de glucómetro portátil de farmacia

ABSTRACT Introduction The individual glucose threshold (IGT) has been used to estimate the anaerobic threshold with low-cost analyses and shorter times. However, the reliability of the glycemic analysis using a portable pharmacy glucose meter has received little attention. Objective To identify the IGT using a portable glucose meter and to compare it with the ventilatory threshold (VT). Methods Fourteen active, healthy men (25.9 ± 3.2 years; %BF = 17.9 ± 3.7%) performed an incremental treadmill test. The anaerobic threshold was identified by two different methods: (1) IGT, corresponding to the intensity of the lowest glucose value during the test; and (2) VT, corresponding to the break in linearity of the ventilation curve and an increase in the respiratory oxygen equivalent, without an equivalent increase in carbon dioxide. Results There were significant differences between VT (9.9 ± 1.2 km/h) and IGT (9.5 ± 1/1 km/h), corresponding to 75.4 ± 9.2 and 72.5 ± 10.4 %VO2max, respectively. The methods presented high correlation (r = 0.82, p = 0.002) and the Bland-Altman technique showed agreement between IGT and VT, with a mean difference of 0.5 km/h. Conclusion It was possible to determine the intensity of IGT by the glycemic response in the incremental test using a portable glucose meter. The IGT underestimated the intensity of VT by approximately 0.5 km/h, but with a high correlation and agreement between them. Level of evidence III, Case-Controle Study.

RESUMO Introdução O limiar glicêmico individual (LGI) tem sido utilizado para estimar o limiar anaeróbico com baixo custo das análises e também em menor tempo. Entretanto, dá-se pouca atenção para a confiabilidade das análises glicêmicas por meio do glicosímetro portátil de farmácia. Objetivo Determinar o LGI por meio de glicosímetro portátil e comparar com o limiar ventilatório (LV). Métodos: Catorze homens saudáveis e ativos (25,9 ± 3,2 anos; %G = 17,9 ± 3,7%) realizaram teste incremental em esteira. Determinou-se o limiar anaeróbico por duas metodologias: (1) LGI, correspondendo à intensidade do menor valor glicêmico durante o teste; (2) LV, correspondendo à quebra da linearidade da curva da ventilação e aumento do equivalente respiratório de oxigênio sem aumento do equivalente de dióxido de carbono. Resultados Foram observadas diferenças significativas entre LV (9,9 ± 1,2 km/h) e LGI (9,5 ± 1,1 km/h), correspondendo a 75,4 ± 9,2 e 72,5±10,4 %VO2máx, respectivamente. As duas metodologias apresentaram correlação alta (r = 0,82; p = 0,002) entre si. A técnica de Bland-Altman evidenciou concordância entre os métodos LGI e LV, com uma diferença média de 0,5 km/h. Conclusão Foi possível determinar a intensidade do LGI por meio da resposta glicêmica em teste incremental com o uso de glicosímetro portátil de farmácia. O LGI subestimou em aproximadamente 0,5 km/h a intensidade do LV, no entanto, com alta correlação e concordância entre eles. Nível de evidência III, Estudo de Caso-controle.

RESUMEN Introducción El umbral glucémico individual (UGI) ha sido utilizado para estimar el umbral anaeróbico con bajo costo de los análisis y también en menor tiempo. Sin embargo, se presta poca atención a la confiabilidad de los análisis glucémicos a través del glucómetro portátil de farmacia. Objetivo Determinar el UGI a través de glucómetro portátil y comparar con el umbral de ventilación (UV). Métodos Catorce hombres sanos y activos (25,9 ± 3,2 años; %G = 17,9 ± 3,7%) realizarán una prueba incremental en cinta. El umbral anaeróbico se determinó mediante dos metodologías: (1) UGI correspondiente a la intensidad del valor glucémico más bajo durante la prueba; (2) UV, correspondiente a la quiebra de la linealidad de la curva de la ventilación y aumento del equivalente respiratorio de oxígeno sin aumento del equivalente de dióxido de carbono. Resultados Se observaron diferencias significativas entre UV (9,9 ± 1,2 km/h) y UGI (9,5 ± 1,1 km/h), correspondiendo a 75,4 ± 9,2 y 72,5 ± 10,4, %VO2max, respectivamente. Las dos metodologías presentaron una correlación alta (r = 0,82, p = 0,002) entre sí. La técnica de Bland-Altman evidenció concordancia entre los métodos UGI y UV, con una diferencia media de 0,5 km/h. Conclusión Fue posible determinar la intensidad del UGI por medio de la respuesta glucémica en prueba incremental con el uso de glucómetro portátil de farmacia. El UGI subestimó en aproximadamente 0,5 km/h la intensidad del UV, sin embargo, con alta correlación y concordancia entre ellos. Nivel de evidencia III, Estudio de caso-control.

Efeito de dois ritmos de dança de salão na resposta da pressão arterial pós-exercício: uma comparação entre o samba e o bolero / Effect of two rhythms of ballroom dance on post exercise blood pressure response: a comparison between samba and bolero

A dança de salão pode representar uma alternativa de exercício físico para controle da pressão arterial (PA), tanto de forma crônica como aguda. O objetivo foi avaliar e comparar a resposta da PA após uma sessão de samba da gafieira e após uma sessão de bolero. Dezenove mulheres não hipertensas (21,9 ± 3,4 anos e IMC de 21,5 ± 2,5 kg/m2) praticantes da dança de salão avançada foram submetidas a duas sessões experimentais de dança de salão com dois ritmos, bolero e samba de gafieira, sendo avaliada a frequência cardíaca (FC) e a pressão arterial (PA) de repouso, durante as sessões (apenas FC) e a cada 10 min durante 60 min após as sessões. Durante as sessões, a FCmédia atingida no bolero foi 145 ± 15 bpm (78 ± 8 %FCmax) e no samba foi 178 ± 13 bpm (92 ± 6 %FCmax), representando intensidade moderada e vigorosa, respectivamente. No ritmo bolero, após 10 min do final da sessão, a pressão arterial sistólica (PAS) já apresentou valores semelhantes (p > 0,05) ao re-pouso (112,0 ± 12,9 mmHg), sendo mantidos até 60 min após a dança. No samba, a PAS entre os 30 a 60 min foi menor (p < 0,05) que em repouso (114,0 ± 13,0 mmHg), evidenciando hipotensão pós-exercício. Não foram observadas reduções da pressão arterial diastólica após as danças. O ritmo mais intenso, representado pelo samba, induziu hipotensão pós-exercício, o que não ocorreu com o ritmo bolero, que apresentou apenas uma diminuição do trabalho do miocárdio.

The ballroom dance could represent an alternative exercise to both acute and chronic control of blood pressure (BP). The objective was to evaluate and to compare the BP response after a single session of samba da gafieira and single session of bolero. Nineteen advanced ballroom dancers and normotensive women (21.9 ± 3.4 years and BMI of 21.5 ± 2.5 kg/m2) performed two experimental sessions of ballroom dancing with two rhythms, bolero and samba de gafieira. Heart rate (HR) and BP were measured before and every 10 min during 60 min following the experimental sessions. HR was also measured during the sessions. Mean HR was 145 ± 15 bpm (78 ± 8 %FCmax) and 178 ± 13 bpm (92 ± 6 %FCmax) for bolero and samba, respectively. This means that the intensity of bolero was moderate and samba was vigorous. After 10 min of bolero and at the end of the evaluation (60 min), systolic blood pressure (SBP) was not different (p > 0.05) from rest (112.0 ± 12.9 mmHg). SBP between the 30th and 60th min following the samba session was different (p < 0.05) from rest (114.0 ± 13.0 mmHg), showing post-exercise hypotension. Diastolic blood pressure did not present reduction following the experimental sessions. The most intense rhythm, representing by samba, elicited post-exercise hypotension, which did not occur with the bolero rhythm. Bolero only presented a decrease in myocardial work.

Estudo do comportamento cortisol, gh e insulina apos uma sessao de exercicio resistido agudo / Study of the behavior of cortisol, gh and insulin after a session of acute resisted exercise / Estudio del comportamiento de cortisol, gh e insulina despues de uma sesion de ejercicio resistido agudo

INTRODUÇÃO: Muitos trabalhos têm estudado o comportamento hormonal nos exercício resistido, entretanto poucos relacionam os hormônios cortisol, GH e insulina. OBJETIVO: Estudar os ajustes das concentrações plasmáticas dos hormônios cortisol, GH e insulina em exercícios resistidos de mesma intensidade com relação à massas musculares distintas. MÉTODOS: Dez voluntários, com 20,3 ± 4,2 anos, 74,1 ± 10,2 kg de peso, 177,2 ± 4,6 cm de estatura e 23,8 ± 3,2 kg/m2 de IMC, realizaram uma sessão de leg press (LP) e supino reto (SR) com quatro séries com 10 repetições a 70% 1 RM com três minutos de intervalo. Foram coletadas amostras de sangue para dosagem das concentrações plasmáticas de cortisol, GH e insulina em repouso (Pré) e em 0' (Rec. 0'), 30' (Rec. 30') e 90' (Rec. 90') de recuperação. RESULTADOS: As concentrações plasmáticas de cortisol foram significativamente reduzidas ao final da recuperação em LP (2,20±0,37 ng/dl para 1,33±0,38ng/dl) em relação à pré-dosagem. As concentrações de GH e insulina elevaram-se significativamente durante a recuperação. GH em LP foi significativamente maior em Rec. 0' (2,75±3,29 ng/ml para 9,60±5,32 ng/dl) do que em pré. A insulina elevou-se significativamente em Rec. 30' em LP (14,70±7,92 ulU/ml para 21,66 ± 8,61 ulU/ml) e em SR (6,17 ± 2,99 ulU/ml para 19,70 ± 13,8 ulU/ml) em relação à pré. As concentrações plasmáticas de insulina pré em LP foram significativamente superiores a SR (14,70 ulU/ml e 6,17 ± 2,99 ulU/ml). CONCLUSÃO: O exercício resistido promoveu diferentes ajustes nas concentrações hormonais de cortisol, GH e insulina durante o período de recuperação. .

INTRODUCTION: Many works have studied the hormonal behavior in resistance exercise, however, few relate the cortisol, GH and insulin hormones. OBJECTIVE: To study the adjustments of plasma concentrations of the cortisol, GH and insulin hormones in resisted exercises of the same relative intensity with different muscle musses. METHODS: Ten volunteers, aged 20.3 ± 4.2 years, weight 74.1 ± 10.2 Kg, 177.2 ± 4.6 cm of stature and 23.8 ± 3.2 Kg/m2 of BMI, underwent a session of leg press (LP) and bench press (BP) with four sets of 10 repetitions at 70% 1 RM with three minutes apart. We collected blood samples to measure plasma concentrations of cortisol, GH and insulin at rest (Pre) and 0' (Rec. 0'), 30' (Rec. 30') and 90' (Rec. 90') of recovery. RESULTS: Plasma concentrations of cortisol decreased significantly at the end of the recovery in LP (2.20 ± 0.37 ng/dl to 1.33 ± 0.38 ng/dl) compared to pre. The GH and insulin concentrations significantly increased during recovery. GH was significantly higher in LP Rec. 0' (2.75 ± 3.29 ng/ml to 9.60 ± 5.32 ng/dl) than in pre. Insulin was significantly elevated in Rec. 30' in LP (14.70 ± 7.92 ulU/ml to 21.66 ± 8.61 ulU/ml) and BP (6.17 ± 2.99 ulU/ml to 19.70 ± 13.8 ulU/ml) for pre. The plasma insulin concentrations pre PL were significantly higher in the BP (14.70 ulU/ml and 6.17 ± 2.99 ulU/ml). CONCLUSION: Resisted exercise promoted different adjustments in hormone concentrations of cortisol, GH and insulin during the recovery period. .

INTRODUCCIÓN: Muchos trabajos han estudiado el comportamiento hormonal en el ejercicio de resistencia, sin embargo, pocos se refieren el cortisol, GH y las hormonas insulina. OBJETIVO: Estudiar los ajustes de las concentraciones plasmáticas de las hormonas cortisol, GH e insulina en ejercicios resistidos, de igual intensidad, en relación con las masas musculares diferentes. MÉTODOS: Diez voluntarios, con 20,3 ± 4,2 años, 74,1 ± 10,2 kg de peso, 177,2 ± 4,6 cm de estatura y 23,8 ± 3,2 kg/m2 de IMC, realizaron una sesión de leg press (LP) y supino recto (SR) con cuatro series, de 10 repeticiones a 70% 1 RM, con tres minutos de intervalo. Se recolectaron muestras de sangre para dosificación de las concentraciones plasmáticas de cortisol, GH e insulina en reposo (Pré) y en 0' (Rec. 0'), 30' (Rec. 30') y 90' (Rec. 90') de recuperación. RESULTADOS: Las concentraciones plasmáticas de cortisol se redujeron significativamente al final de la recuperación en LP (2,20±0,37 ng/dl para 1,33±0,38ng/dl) en relación con la predosificación. Las concentraciones de GH e insulina aumentaron significativamente durante la recuperación. GH en LP fue significativamente mayor en Rec. 0' (2,75±3,29 ng/ml para 9,60±5,32 ng/dl) en comparación con la predosificación. La insulina se elevó significativamente en Rec. 30' en LP (14,70±7,92 ulU/ml para 21,66 ± 8,61 ulU/ml) y en SR (6,17 ± 2,99 ulU/ml para 19,70 ± 13,8 ulU/ml) en relación con la predosificación. Las concentraciones plasmáticas de insulina, predosificación, en LP fueron significativamente superiores a SR (14,70 ulU/ml y 6,17 ± 2,99 ulU/ml). CONCLUSIÓN: El ejercicio resistido causó diferentes ajustes en las concentraciones hormonales de cortisol, GH e insulina durante el período de recuperación. .

Resistance training restores the gene expression of molecules related to fat oxidation and lipogenesis in the liver of ovariectomized rats.

Decreased levels of estrogen are associated with hepatic steatosis (HS), through changes in gene expression of molecules related to fat oxidation and lipogenesis. Both resistance training (RT) and endurance training (ET) prevent HS in ovariectomized (Ovx) rats. However, the molecular events associated with this process were only investigated for ET, but not for RT. Thus, the aim of this study was to investigate the effects of Ovx and RT on the gene expression of molecules related to fat oxidation and lipogenesis in the liver of rats. Sprague-Dawley adult female rats were grouped into four (n = 6 per group): sham-operated sedentary (Sham-Sed); Ovx sedentary (Ovx-Sed); sham-Rt and Ovx-Rt. A 10-week RT period, during which the animals climbed a 1.1-m vertical ladder with weights attached to their tails, was used. The sessions were performed three times a week, with 4-9 climbs and 8-12 dynamic movements per climb. Gene expression was analyzed by RT-PCR by the ∆∆Ct method. The estrogen deficiency associated with ovariectomy decreased the gene expression of molecules related to fat oxidation, carnitine palmitoyltransferase I (53%) and ß-hydroxyacyl-CoA dehydrogenase (27%), and increased molecules related to lipogenesis, sterol regulatory element-binding protein-1c (106%), acetyl-CoA carboxylase (ACC) (72%) and stearoyl CoA desaturase-1 (109%). With the exception of ACC, the ovariectomy-induced changes in the expression of these molecules were restored by RT. The present results indicate that RT has important effects on the prevention of HS in Ovx animals, through changes in gene expression of molecules related to hepatic lipid metabolism.