Potencia muscular y cinética de lactato en sangre entre genotipos de ACTN3 / Muscle Power and Blood Lactate Kinetics Among ACTN3

En este trabajo se estudiaron las diferencias en la potencia muscular y la cinética de las concentraciones de lactato en sangre ([LA-]b) entre genotipos de ACTN3 durante la prueba anaeróbica de Wingate, (PAnW). Participaron 35 voluntarios (18-35 años) masculinos, sanos y físicamente activos. Se analizaron la potencia muscular, las concentraciones de [LA-]b y la actividad de la Lactato Deshidrogenasa (LDH). El gen ACTN3 se determinó a partir de ADN de glóbulos blancos en sangre periférica. Independientemente del peso y masa muscular de los participantes, los portadores del genotipo RR vs. RX y XX desarrollaron mayor potencia muscular durante la PAnW (p<0.05), lo cual sugiere una mayor capacidad en este genotipo para utilizar el sistema ATP-PC durante un ejercicio supramáximo. La cinética en la potencia muscular y en las concentraciones de [LA-]b fueron semejantes entre genotipos. La PAnW no fue suficiente para causar daño muscular observado por la concentración de LDH. (AU)

In this work, the differences in the muscle power and the kinetics of blood lactate concentrations ([LA-]b) between ACTN3 genotypes were studied during the Wingate anaerobic test (PAnW). Thirty-five healthy and physically active male volunteers (18-35 years old) participated. Muscle power, [LA-] b concentrations, and Lactate Dehydrogenase (LDH) activity were analyzed. The ACTN3 gene was determined from the DNA of white blood cells in peripheral blood. Regardless of the participants' weight and muscle mass, carriers of the RR genotype vs. RX and XX developed greater muscle power during PAnW (p <0.05), suggesting a greater capacity in this genotype to use the ATP-PC system during supramaximal exercise. The kinetics in muscle power and in [LA-]b concentrations were similar between genotypes. PAnW was not enough to cause muscle damage seen by LDH concentration. (AU)

Respuesta de creatina quinasa a un ejercicio anaerobio supramáximo en genotipos de ACTN3 / Response of Creatine Kinase to an Anaerobic Supramaximal Exercise in ACTN3 Genotypes

El objetivo del presente estudio fue investigar las diferencias en la actividad de la enzima Creatina Quinasa (CK) en pre y post ejercicio anaerobio supramáximo (EASM) en portadores de los genotipos del gen de la alfa-actinina-3 (ACTN3). Se reclutaron 39 hombres sanos físicamente activos (18-35 años) y se sometieron a un EASM de 30 s (Wingate). El gen ACTN3 se determinó a partir del ADN de glóbulos blancos en sangre periférica y se evaluó la actividad de la CK en muestras sanguíneas en condiciones basales, a las 24 y 48 h post EASM. Los portadores del genotipo XX vs RR presentaron 1,4 veces menor actividad de CK en condiciones basales (p < 0,05) y una mayor actividad de CK a las 24 h post ejercicio (p < 0,05). Una serie de EASM fue capaz de causar un incremento significativo de la actividad de CK a las 24 h en los portadores del genotipo XX

The aim of the present study was to investigate the differences in the activity of the enzyme Creatine Kinase (CK) in pre and post anaerobic supramaximal exercise (ASME) on carriers of the genotypes of the alpha-actinin-3 gene (ACTN3). 39 healthy physically active men (18-35 years) were enrolled and underwent an ASME of 30 s (Wingate). The ACTN3 gene was determined from the DNA of white blood cells in peripheral blood and the CK activity was evaluated in blood samples in basal conditions, at 24 and 48 h after of ASME. The carriers of genotype XX vs RR had 1.4 times lower CK activity in basal conditions (p < 0.05) and higher CK activity at 24 h after exercise (p < 0.05). A series of ASME was capable of causing a significant increase in CK activity at 24 h in the XX genotype carriers

Metabolic power and cardiovascular response of a low cadence-high height bench stepping exercise in healthy young people.

AIM: The aim of this paper was to study the feasibility of bench stepping at a low cadence as a safe exercise that can provide enough cardiovascular fitness that be performed by any person. METHODS: Thirty-three men and twenty-one young women (age =23±3 yrs; weight =70±13 kg; height 170±9 cm) participated in this study. Each one held a continuous 20 minute (4 stages /5 min each) bench stepping workout session with two different step heights (31 and 41 cm) and two different intensities (60 and 90 steps∙min-1). Body weight (bw), total & trochanteric height, heart rate (HR, beats∙min-1), rated perceived exertion (RPE) and O2 consumption (VO2) were recorded. RESULTS: From the 1st through the 4th stage, the vertical distance (VD, m), RPE, HR and VO2 values were 4.6-9.23 m, 2.5-6.7, 118-168 beats∙min-1 and 20.8-34.0 ml∙kg-1∙min-1, respectively. The best regression model to calculate the O2 consumption (VO2) was: VO2 (L∙min-1) =-1.264+0.026∙bw (kg)+0.195∙VD (m). VD, bw, and gender determined, independently, the changes of caloric expenditure (R2=0.92). CONCLUSION: The energy expenditure of a low cadence stepping exercise (15-22 cycles∙min-1) at 31-41 cm bench height, is enough to improve aerobic fitness which in turn may benefit cardiovascular health.

Immunological changes after a single bout of moderate-intensity exercise in a hot environment

This study was aimed to evaluate the possible changes caused by a single bout ofmoderate-intensity exercise in a hot environmental temperature on the immune functionand on inflammatory markers. A total of 22 young male adults (VO2max, 55.4 ¡¾3.6 ml¡¤kg-1¡¤min-1) volunteered to participate in an exercise session of 60 minutes on atreadmill ergometer at moderate speed (60% of the maximum aerobic speed) in hotenvironmental conditions (35 ¨¬C and humidity 60%). Total leukocyte numbers, lymphocytesubsets (CD8+, CD4+, CD3+, NK and CD19+), cytokine productioncapacity by peripheral blood mononuclear cells (PBMCs) (IL-2, IL-4, IL-5, IL-10,IFN-¥ã and TNF-¥á) as well as the concentration of several inflammation related proteins(ceruloplasmin, C-reactive protein (CRP), complement factors C3 and C4)were evaluated before and after exercise. The results show that leukocyte and neutrophilabsolute values increased (P<0.001) after the exercise period. In contrast,eosinophil values decreased (P<0.05) after the exercise. In addition, ceruloplasmin,C3 and C4 values (P<0.05) increased after exercise. No changes in T lymphocyte subsets,cytokine production, or CRP were observed. These data confirm previous studiessuggesting that a 60 min exercise in a hot environment is enough to cause a physiologicadaptation to these special conditions leading to an increase of non-specificimmune cells and promoting inflammatory processes. On the other hand, PCR values, lymphocyte subsets and the capacity of cytokine production by PBMC were notchanged in a relatively short bout of exercise under these conditions in contrast withprevious studies (AU)

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Immunological changes after a single bout of moderate-intensity exercise in a hot environment.

This study was aimed to evaluate the possible changes caused by a single bout of moderate-intensity exercise in a hot environmental temperature on the immune function and on inflammatory markers. A total of 22 young male adults (VO2(max), 55.4 +/- 3.6 ml x kg(-1) x min(-1)) volunteered to participate in an exercise session of 60 minutes on a treadmill ergometer at moderate speed (60% of the maximum aerobic speed) in hot environmental conditions (35 degrees C and humidity 60%). Total leukocyte numbers, lymphocyte subsets (CD8+, CD4+, CD3+, NK and CD19+), cytokine production capacity by peripheral blood mononuclear cells (PBMCs) (IL-2, IL-4, IL-5, IL-10, IFN-gamma and TNF-alpha) as well as the concentration of several inflammation related proteins (ceruloplasmin, C-reactive protein (CRP), complement factors C3 and C4) were evaluated before and after exercise. The results show that leukocyte and neutrophil absolute values increased (P < 0.001) after the exercise period. In contrast, eosinophil values decreased (P < 0.05) after the exercise. In addition, ceruloplasmin, C3 and C4 values (P < 0.05) increased after exercise. No changes in T lymphocyte subsets, cytokine production, or CRP were observed. These data confirm previous studies suggesting that a 60 min exercise in a hot environment is enough to cause a physiologic adaptation to these special conditions leading to an increase of non-specific immune cells and promoting inflammatory processes. On the other hand, PCR values, lymphocyte subsets and the capacity of cytokine production by PBMC were not changed in a relatively short bout of exercise under these conditions in contrast with previous studies.