Resistance Exercise: Acute and Chronic Changes in Growth Hormone Concentrations

Kraemer, William J.; Nindl, Bradley C.; Gordon, Scott E.

doi:10.1002/9780470757826.ch9

Cited by 5 publications

(4 citation statements)

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“…The GH response to RE has been well characterized [34] and is traditionally known to be influenced by chronological age, amount of muscle mass recruited, type of muscle action (concentric or eccentric), exercise load, training status (an athlete versus a sedentary individual), volume of exercise, and the amount of rest given between sets of exercise. In young men, we observed that low-load RE with BFR produces a similar increase in GH to that of high-load RE, which corroborates the findings of several previous studies [16–22].…”

Section: Discussionmentioning

confidence: 99%

Growth hormone responses to acute resistance exercise with vascular restriction in young and old men

Manini

Yarrow

Buford

et al. 2012

Growth Hormone & IGF Research

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Objective Resistance exercise (RE) stimulates growth hormone (GH) secretion in a load-dependent manner, with heavier loads producing larger GH responses. However, new research demonstrates that low-load RE performed with blood flow restriction (BFR) produces potent GH responses that are similar to or exceed those produced following high-load RE. We hypothesized that low-load RE with vascular restriction would attenuate the known age-related reduction in GH response to RE. Design In a randomized crossover design, ten young (28±7.8 years) and ten older (67.4±4.6 years) men performed bilateral knee extension RE with low-load [20% of one-repetition maximum (1RM)] with BFR and high-load (80% 1RM) without BFR. GH and lactate were measured every 10 minutes throughout a 150-minute testing session (30 minutes prior to and 120 minutes following completion of the exercise); IGF-I was measured at baseline and 60 minutes post-exercise. Results Area under the GH curve indicated that both age groups responded similarly to each exercise condition. However, young men had a significantly greater maximal GH response to low-load RE with BFR than the high-load condition without BFR. Additionally, younger men had greater maximal GH concentrations to low-load RE with BFR than older men (p=0.02). The GH responses were marginally correlated to lactate concentration (r=0.13, p=0.002) and IGF-I levels were unchanged with RE. Conclusions GH responses to low-load RE with vascular restriction are slightly higher than high-load RE without vascular restriction in young men. However, low-load RE with vascular restriction did not attenuate the known age-related reduction in GH response with exercise. These data suggest that while low-load RE with vascular restriction is as effective for inducing a GH response than traditionally-based high-load RE, there is a more potent response in young men.

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Section: Discussionmentioning

confidence: 99%

Growth hormone responses to acute resistance exercise with vascular restriction in young and old men

Manini

Yarrow

Buford

et al. 2012

Growth Hormone & IGF Research

View full text Add to dashboard Cite

show abstract

“…Although radioimmunoassays [15,16] have been used in the past to detect and quantify those peptides, they have been replaced by other assays like enzyme-linked immunosorbent assay [7,8] as well as chemiluminescence and fluorescence immunoassays [9]. Even though such tests provide good selectivity and allow a picomolar limit of detection (LOD), they nevertheless induce cross-reactivity and cannot allow distinction between analogs [11,[17][18][19]. Liquid chromatography techniques coupled with mass spectrometry (MS) have therefore been often used to analyze the GHRH analogs [20].…”

Section: Introductionmentioning

confidence: 99%

Online large volume sample staking preconcentration and separation of enantiomeric GHRH analogs by capillary electrophoresis

et al. 2023

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A capillary electrophoresis method is proposed to analyze the four most wellknown growth hormone-releasing hormone (GHRH) analogs that are misused by athletes. Dimethyl-β-cyclodextrin used as a chiral selector allowed, for the first time, the separation of those basic peptide analogs, including enantiopeptides (sermorelin and CJC-1293) that differ by the chirality of only one amino acid. To increase the method sensitivity, electrokinetic preconcentration methods have been investigated. The large volume sample stacking with polarity switching (PS-LVSS) method with an injected sample volume corresponding to 80% of the capillary one was found superior to the sweeping in terms of signal enhancement factor (SEF). Acid and organic solvent addition to the sample (0.1 mM phosphoric acid with 30% methanol) led to a twofold signal improvement, when compared to water as a matrix. We increased capillary dimensions to provide a signal enhancement through the injection of a larger sample volume. Finally, using a combination of the optimized PS-LVSS preconcentration with the chiral capillary zone electrophoresis (CZE), the GHRH analogs were separated and limits of detection between 75 and 200 ng/mL were reached. This method was successfully applied to urine after a desalting step. An optimized C18 SPE was used for that purpose in order to provide low sample conductivity (<130 µS/cm) and preserve the efficiency of LVSS preconcentration. SEF of 640 was obtained with desalted urine spiked with sermorelin by comparison to the CZE (without preconcentration) method.

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“…que inibe a secreção do GH, e o hormônio liberador de GH (GHRH -growth hormone releasing hormone) (CRUZAT et al, 2008) Diversos fatores podem influenciar a secreção ou inibição do GH, podendo se destacar: o estado nutricional, a quantidade de sono e de gordura corporal, o nível de stress, a prática da atividade física e o nível de treinamento que se encontra o praticante (CRUZAT et al, 2008;KRAEMER et al, 2005). A Tabela 1 elenca os principais fatores de estímulo e supressão da secreção do GH.…”

Section: Justificativaunclassified

“…A Tabela 1 elenca os principais fatores de estímulo e supressão da secreção do GH. Kraemer et al (2005).…”

Section: Justificativaunclassified

Cinética do eixo GH/IGF-I em militares da Força Aérea Brasileira durante instrução de sobrevivência na selva

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Aos meus pais, Laércio e Sílvia, por me concederem o dom da vida e guiarem meus passos até que eu pudesse caminhar sozinho. Aos meus irmãos, José Fernando e Ana, que sempre acreditaram em meus devaneios e me motivaram em minhas conquistas. Aos meus avós, Manoel(in memorian) e Ana, pela atenção e amor que sempre me dispensaram.A minha esposa Flávia que esteve comigo em todos os momentos desta etapa e ao meu filho André, que, junto dela, compreenderam meus afastamentos para a realização desse trabalho.Aos meus amigos e irmãos de farda Major Duque, Capitão Botta, Tenente Fortes, Sargento Antônio e Sargento Gustavo, pelo apoio com o ingresso na pós-graduação, com a conclusão dos créditos e com a coleta das amostras.Aos meus grandes mentores nessa jornada, Prof. Dr. Carlos Eduardo Martinelli Júnior e Prof.Dr. Hugo Tourinho Filho, pela compreensão e apoio durante essa jornada, ambos são exemplos de humildade e profissionalismo, sem os quais eu não poderia ter sido oportunizado com essa experiência ímpar no meio acadêmico. Obrigado pelas orientações, pela confiança e pela amizade durante esse projeto. À Escola de Educação Física e Esporte de Ribeirão Preto, através de seu corpo docente e administrativo, que me proporcionaram um imensurável crescimento profissional e pessoal.Por fim, a todos que, de alguma forma, contribuíram para a efetivação desse estudo. Muito obrigado."A vitória está reservada àqueles que antecipam os novos desenvolvimentos na natureza da guerra e não àqueles que se adaptam a estes desenvolvimentos depois que ocorrem. […] Aquele que não estiver preparado para travar o novo tipo de guerra não terá tempo para preparar-se, nem de reagir. Aquele que for o primeiro a preparar-se, arrastará rapidamente a vitória com o mínimo de meios e sacrifícios".

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Resistance Exercise: Acute and Chronic Changes in Growth Hormone Concentrations

Cited by 5 publications

References 50 publications

Growth hormone responses to acute resistance exercise with vascular restriction in young and old men

Growth hormone responses to acute resistance exercise with vascular restriction in young and old men

Online large volume sample staking preconcentration and separation of enantiomeric GHRH analogs by capillary electrophoresis

Cinética do eixo GH/IGF-I em militares da Força Aérea Brasileira durante instrução de sobrevivência na selva

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