Lactate Release, Concentration in Blood, and Apparent Distribution Volume after Intense Bicycling.

Medbø, Jon Ingulf; Toska, Karin

doi:10.2170/jjphysiol.51.303

Cited by 24 publications

(20 citation statements)

References 33 publications

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“…Despite the various sources of error described for this method in the literature (ex. Medbø and Toska, 2001), in our opinion, the main limitation to its application in RE is that every study that has supported the BL energy equivalent was performed on running, cycling or swimming exercise. Therefore, there are no experimental data that may support the value for the BL energy equivalent in RE.…”

Section: Introductionmentioning

confidence: 99%

Energy Cost of Resistance Exercises: an Uptade

Reis¹,

Júnior²,

Zając³

et al. 2011

Journal of Human Kinetics

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The use of resistance exercises and of typical strength training methods have been progressively used to control body mass and to promote fat mass loss. The difficulties involved in the energy cost calculation during strength training are associated with the large amount of exercises and their several variations. Mean values between ≈3 and 30 kcal·min−1 are typically reported but our studies indicate that it may attain values as high as 40 kcal·min−1 in exercises which involve a large body mass. Therefore, in our opinion, the next step in research must be the isolated study of each of the main resistance exercises. Since the literature is scarce and that we do consider that the majority of the studies present severe limitations, the aim of this paper is to present a critical analysis of the energy cost estimation methods and provide some insights that may help to improve knowledge on resistance exercise. It seems necessary to rely on the expired O2 measurements to quantify aerobic energy. However, it is warranted further attention on how this measure is performed during resistance exercises. In example, studies on the O2 on-kinetics at various conditions are warranted (i.e. as a function of intensity, duration and movement speed). As for anaerobic lactic energy, it is our opinion that both the accumulated oxygen deficit and the blood lactate energy equivalent deserve further studies; analyzing variations of each method as an attempt to establish which is more valid for resistance exercise. The quantification of alactic anaerobic energy should be complemented by accurate studies on the muscle mass involved in the different resistance exercises. From the above, it is concluded that knowledge on the energy cost in resistance exercises is in its early days and that much research is warranted before appropriate reference values may be proposed.

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Section: Introductionmentioning

confidence: 99%

Energy Cost of Resistance Exercises: an Uptade

Reis¹,

Júnior²,

Zając³

et al. 2011

Journal of Human Kinetics

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“…Contudo, a capacidade produtora de lactato do GC também aumentou significativamente após esse período, descartando assim a hipótese de alterações em função do treinamento. Medbø e Toska (23) demonstraram que a concentração sanguínea de lactato não reflete a produção energética real oriunda do glicogênio muscular. No entanto, outros pesquisadores verificaram que a formação de lactato pode estar relacionada com a taxa de depleção energética pelo glicogênio muscular (24,25) , podendo inclusive ser utilizado ao longo do treinamento como marcador de supertreinamento (24) .…”

Section: Discussionunclassified

Padronização de um protocolo experimental de treinamento periodizado em natação utilizando ratos Wistar

Araújo

Papoti

Manchado-Gobatto

et al. 2010

Rev Bras Med Esporte

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RESUMOVerificar os efeitos de 12 semanas de treinamento periodizado de natação em ratos sobre os valores de glicogênio muscular (GM) e hepático (GH), capacidade aeróbia (LAn) e anaeróbia (Tlim) e creatina quinase (CK). Foram utilizados 70 ratos da linhagem Wistar com 60 dias, adaptados individualmente ao meio líquido por duas semanas. Os animais foram divididos em grupos: controle (GC, n = 40) e periodizado (GP, n = 30); a intensidade do treinamento foi equivalente ao peso corporal do animal (% do PC). O treinamento (T) para o GP foi dividido em períodos preparatório básico (PPB, seis semanas), específico (PPE, 4,5 semanas) e polimento (PP, 1,5 semana), tendo como estímulos intensidades leve (4% do PC), moderada (5% do PC), pesada (6% do PC) e intensa (13% do PC). Vinte e quatro horas após a adaptação, 10 ratos do GC foram sacrificados e avaliados pelo teste de lactato mínimo para mensuração dos valores de linha de base de GM, GH, CK, LAn e Tlim. Os dez animais restantes do GC e GP foram sacrificados ao final de cada período de T. O treinamento periodizado aumentou a concentração de glicogênio muscular ao final do período de polimento. O glicogênio hepático não se alterou no GC, porém no GP houve redução significativa no início do período específico com elevação no período de polimento. A concentração de CK não se modificou ao final dos PPB, PPE e PP. O LAn reduziu ao longo do período experimental no GC, mas ao final do PP para o GP, o LAn atingiu os mesmos valores do início do treinamento. O Tlim aumentou no PP. Desse modo, pode-se concluir que o treinamento periodizado provocou supercompensação energética ao final da periodização. A capacidade anaeróbia aumentou no PP bem como o LAn, que obteve maiores valores em relação ao GC nesse período.Palavras-chave: glicogênio, capacidade aeróbia, capacidade anaeróbia e creatina quinase. ABSTRACTThe objective of this study was to verify the swimming training periodization responses on aerobic and anaerobic performance, glycogen concentration in muscle (M) and liver (L), and creatine kinase (CK) in rats. Seventy male Wistar rats were randomly separated in two groups: Control Group (CG n = 30) and Training Periodization Group (TPG n = 30). All experiments were preceded by 2 weeks of individual adaptation to the water. The TPG was carried out during a period of 12 weeks (w) with frequency of 6 days/w. The training period was subdivided in three specialized series blocks: Preparation (6 w), Specific (4.5 w) and Taper (1.5 w). The Lactate Minimun Test (LACm) was adapted to determine the aerobic capacity. Anaerobic performance was evaluated by maximal exhaustion time (Tlim) verified during hyperlactatemia induction phase in the LACm protocol. Training stimulus was based on intensities corresponding to the LACm: Endurance (END) 1 = 80%; END2= 100%; END3= 120% and Anaerobic (ANA) 240% of the LACm. Two-way Anova and Newman-Keuls post-hoc test (P<0.05)were also used. Aerobic performance was not different from initial training (Preparation: 4.57 ± 0.24% of body weigh (bw); Specifi...

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“…After a 10 min rest he cycled at a constant power established during the pretests for ≈2 min to exhaustion. Blood samples from the femoral artery and vein were drawn in parallel in 5 ml syringes before the exercise, after 30, 60 and 90 s of exercise, and at 30 s, 1,3,6,10,15,20,30,45, and 60 min after the exhausting bout. The blood samples were handled as described elsewhere [24] to allow measurement of haematocrit (Hct), blood lactate (La) and haemoglobin (Hb) concentrations, blood acidbase parameters (pH, pCO 2 , pO 2 , sO 2 ), concentration of plasma electrolytes (Na + , K + , Cl -, La -, HCO 3 -), and plasma albumin, and proteins.…”

Section: Methodsmentioning

confidence: 99%

“…Their approach assumes sufficiently fast equilibration of lactic acid and bicarbonate in all extracellular space, which may not be the case [30]. A further discussion of possible excess release of hydrogen ions is beyond the scope of the present paper.…”

Section: Base Deficit and Excess Hydrogen Ionsmentioning

confidence: 99%

Acid-base status of arterial and femoral-venous blood during and after intense cycle exercise

Medbø

Noddeland²,

Hanem³

2012

AKUT

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Intense exercise depends on energy from both aerobic and anaerobic processes. These processes produce CO 2 and lactate, respectively, and both metabolites affect blood's acid-base status. To examine how the acid-base status of arterial and femoral-venous blood is affected and regulated, seven healthy young men cycled for 2 min at constant power to exhaustion. Blood samples were drawn from indwelling catheters in the femoral artery and vein during exercise and for 1 h after, and the samples were analysed for lactate (La -), acid-base parameters, and plasma electrolytes (Na. The chloride concentration in red blood cells (cCl RBC ) was also determined to quantify the chloride shift. Arterial (femoral-venous, fv, mean values) blood lactate concentration rose to 13.8 mmol L -1 (fv 15.7), pH fell to 7.18 (fv 7.00), pCO 2 changed to 41 hPa (fv 114), and blood bicarbonate concentration was more than halved after exercise. cCl RBC rose by 5 (a) and 8 mmol L -1 blood (fv) during exercise. pCO 2 and pH fell linearly by the lactate concentration. Consequently, blood bicarbonate concentration fell by 81% of the increase in blood lactate concentration, while blood base deficit rose 30% more than lactate did. Bicarbonate thus neutralised 62% of the total acid load. cCl RBC rose in proportion to the amount of hydrogen ions buffered by haemoglobin, and chloride shift amounted to 31% of the total acid load. pH was lower and pCO 2 and bicarbonate concentration were higher in femoral-venous than in arterial blood with the same lactate Acid-base status of arterial and femoral-venous blood … 67 concentrations. The relationship between base deficit and blood lactate concentration did not differ between arterial and femoral-venous blood. In conclusion, after intense exercise pH falls more in femoralvenous than in arterial blood because of a lack of respiratory compensation of the metabolic acidosis.

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Lactate Release, Concentration in Blood, and Apparent Distribution Volume after Intense Bicycling.

Cited by 24 publications

References 33 publications

Energy Cost of Resistance Exercises: an Uptade

Energy Cost of Resistance Exercises: an Uptade

Padronização de um protocolo experimental de treinamento periodizado em natação utilizando ratos Wistar

Acid-base status of arterial and femoral-venous blood during and after intense cycle exercise

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