Pesos leves permanecem Anabólicos
Você é um
bodybuilder, mas só pode treinar com pessos leves devido a alguma lesão, e você
está preocupado com sua massa muscular. Esse é o seu problema?
Então cientistas
esportivos da Universidade de Copenhagen têm boas notícias para você. Mesmo que
você só possa treinar com pesos mais leves isso ajudará você a manter parte de
sua massa muscular, o Danes escreve um artigo que será publicado no Clinical
Nutrition. Pelo menos, se você consumir proteína o bastante.
Em 2008 o danes fez uma descoberta que atletas de força provavelmente reagiriam dizendo “mas nós já sabemos disso.” [J Appl Physiol. 2008 Nov; 105(5): 1454-61.]. Os pesquisadores pegaram fizeram os voluntários os quadriceps na máquina extensora por 12 semanas. Os homens que treinaram unilateral realizando sets usando 70% de sua 1RM(1 repetição máxima) e o restante usando 16% desse peso(leve).
Copiamos a figura abaixo do estudo deles. Ele mostra a circunferência do quadríceps dos indivíduos antes de depois das 12 semanas. O treino mais pesado teve mais efeito que o mais leve.
Em 2008 o danes fez uma descoberta que atletas de força provavelmente reagiriam dizendo “mas nós já sabemos disso.” [J Appl Physiol. 2008 Nov; 105(5): 1454-61.]. Os pesquisadores pegaram fizeram os voluntários os quadriceps na máquina extensora por 12 semanas. Os homens que treinaram unilateral realizando sets usando 70% de sua 1RM(1 repetição máxima) e o restante usando 16% desse peso(leve).
Copiamos a figura abaixo do estudo deles. Ele mostra a circunferência do quadríceps dos indivíduos antes de depois das 12 semanas. O treino mais pesado teve mais efeito que o mais leve.
O treino
pesado resultou em um aumento de 7,5% na circunferência muscular; o leve em
2,5% de aumento. A segunda figura intrigou os pesquisadores. Aparentemente
treinar com peso muito leve também ajuda o músculo a crescer. E isso é de
interesse de pessoas que querem reter massa muscular, mas por uma razão ou
outra não conseguem treinar com cargas mais elevadas.
Os
pesquisadores em breve publicarão os resultados de um estudo em que eles
examinaram a relação entre suplementação protéica e treino leve. Nesse estudo o
Danes usou 10 homens na casa dos 20 como voluntários. Eles fizeram os
indivíduos treinarem apenas uma perna na máquina extensora, usando carga
referente a 16% de sua 1RM, logo cedo pela manhã. Para cada exercício que eles
faziam 10 sets de 36 repetições. Entre as séries os indivíduos descansavam 30
segundos. Na outra perna eles não fizeram nada.
Na 10 horas seguidas após esse treino desequilibrado Danes
monitorou a produção de tecido muscular nos quadriceps dos indivíduos. Também
foi dado a eles shakes pequenos de proteína, inicialmente toda meia-hora e
posteriormente a cada hora. No total os indivíduos consumiram por volta de 12
shakes, com total de 65g de proteína.
A figura abaixo mostra que na perna que não foi treinada o efeito anabólico protéico desapareceu após 8 horas, mas na perna treinada ficou até 10 horas após o treino.
A figura abaixo mostra que na perna que não foi treinada o efeito anabólico protéico desapareceu após 8 horas, mas na perna treinada ficou até 10 horas após o treino.
“Deve ser
reconhecido que exercícios com alta carga são os melhores para estimular a
modificação muscular protéica e o crescimento muscular”, os pesquisadores
escreveram. “O fenômeno que treino de resistência de baixa carga produz
contração o suficiente para aumentar a sensibilidade muscular para o
abastecimento protéico, deve proporcionar suporte para o efeito de preservação
muscular. Os resultados podem ser relevantes para pacientes hospitalizados ou
parcialmente imobilizados, que podem hipoteticamente atenuar a atrofia muscular
por completar um pequena atividade de contração com baixa carga combinada com dieta
de suplementação protéica.”
Mudanças
no tamanho muscular e composição MHC em resposta ao exercício de resistência
com intensidade e alta carga e baixa carga.
Holm L,
Reitelseder S, Pedersen TG, Doessing S, Petersen SG, Flyvbjerg A, Andersen JL,
Aagaard P, Kjaer M.
Source
Institute of Sports Medicine,Bispebjerg
Hospital , Bispebjerg Bakke 23, DK-2400
Copenhagen NV , Denmark
Abstract
Muscle mass accretion is accomplished by heavy-load resistance training. The effect of light-load resistance exercise has been far more sparsely investigated with regard to potential effect on muscle size and contractile strength. We applied a resistance exercise protocol in which the same individual trained one leg at 70% of one-repetition maximum (1RM) (heavy load, HL) while training the other leg at 15.5% 1RM (light load, LL). Eleven sedentary men (age 25 +/- 1 yr) trained for 12 wk at three times/week. Before and after the intervention muscle hypertrophy was determined by magnetic resonance imaging, muscle biopsies were obtained bilaterally from vastus lateralis for determination of myosin heavy chain (MHC) composition, and maximal muscle strength was assessed by 1RM testing and in an isokinetic dynamometer at 60 degrees /s. Quadriceps muscle cross-sectional area increased (P < 0.05) 8 +/- 1% and 3 +/- 1% in HL and LL legs, respectively, with a greater gain in HL than LL (P < 0.05). Likewise, 1RM strength increased (P < 0.001) in both legs (HL: 36 +/- 5%, LL: 19 +/- 2%), albeit more so with HL (P < 0.01). Isokinetic 60 degrees /s muscle strength improved by 13 +/- 5% (P < 0.05) in HL but remained unchanged in LL (4 +/- 5%, not significant). Finally, MHC IIX protein expression was decreased with HL but not LL, despite identical total workload in HL and LL. Our main finding was that LL resistance training was sufficient to induce a small but significant muscle hypertrophy in healthy young men. However, LL resistance training was inferior to HL training in evoking adaptive changes in muscle size and contractile strength and was insufficient to induce changes in MHC composition.
PMID: 18787090 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/pubmed/18787090
The anabolic potential of dietary protein intake on skeletal muscle is prolonged by prior light-load exercise.
Bechshoeft R, Dideriksen KJ, Reitelseder S, Scheike T, Kjaer M, Holm L.
Source
Institute of Sports Medicine, Dept. of Orthopedic Surgery M81, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
Abstract
BACKGROUND & AIMS:
Hyperaminoacidemia stimulates myofibrillar fractional synthesis rate (myoFSR) transiently in resting skeletal muscle. We investigated whether light-load resistance exercise can extent this responsiveness.
METHODS:
Ten healthy males exercised one leg with a light-load resistance-like exercise at 16% of 1 repetition maximum and received oral protein boluses every hour for a 10-h period. Their myoFSR was determined by [1-(13)C]-leucine incorporation. Muscle biopsies were obtained from the resting (REST) and exercised (EXC) muscles every 2.5-h in the protein-fed period.
RESULTS:
Protein feeding significantly elevated plasma leucine and essential amino acids by an average of 39 ± 9% (mean ± SEM) and 20 ± 4%, respectively, compared to the basal concentrations: 197 ± 12 μmol L(-1) and 854 ± 35 μmol L(-1), respectively. The myoFSR was similar in EXC and REST muscles in the first 8 h (all time intervals p > 0.05). After 8 h the myoFSR dropped in the REST muscle to 0.041 ± 0.005%·h(-1), which was 65 ± 5% of the rate in EXC leg at the same time point (0.062 ± 0.004%·h(-1)) and 80 ± 14% of the level in REST leg from 0.5 to 8 h (0.056 ± 0.005%·h(-1)) (interaction p < 0.05).
CONCLUSIONS:
Compared to rest, light-load exercise prolonged the stimulatory effect of dietary protein on muscle biosynthesis providing perspectives for a muscle restorative effect in clinical settings where strenuous activity is intolerable.
Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
PMID: 22867749 [PubMed - as supplied by publisher]
Source: http://www.ncbi.nlm.nih.gov/pubmed/22867749
Source: http://www.ironmagazine.com/2013/tra...pplementation/
Source
Institute of Sports Medicine,
Abstract
Muscle mass accretion is accomplished by heavy-load resistance training. The effect of light-load resistance exercise has been far more sparsely investigated with regard to potential effect on muscle size and contractile strength. We applied a resistance exercise protocol in which the same individual trained one leg at 70% of one-repetition maximum (1RM) (heavy load, HL) while training the other leg at 15.5% 1RM (light load, LL). Eleven sedentary men (age 25 +/- 1 yr) trained for 12 wk at three times/week. Before and after the intervention muscle hypertrophy was determined by magnetic resonance imaging, muscle biopsies were obtained bilaterally from vastus lateralis for determination of myosin heavy chain (MHC) composition, and maximal muscle strength was assessed by 1RM testing and in an isokinetic dynamometer at 60 degrees /s. Quadriceps muscle cross-sectional area increased (P < 0.05) 8 +/- 1% and 3 +/- 1% in HL and LL legs, respectively, with a greater gain in HL than LL (P < 0.05). Likewise, 1RM strength increased (P < 0.001) in both legs (HL: 36 +/- 5%, LL: 19 +/- 2%), albeit more so with HL (P < 0.01). Isokinetic 60 degrees /s muscle strength improved by 13 +/- 5% (P < 0.05) in HL but remained unchanged in LL (4 +/- 5%, not significant). Finally, MHC IIX protein expression was decreased with HL but not LL, despite identical total workload in HL and LL. Our main finding was that LL resistance training was sufficient to induce a small but significant muscle hypertrophy in healthy young men. However, LL resistance training was inferior to HL training in evoking adaptive changes in muscle size and contractile strength and was insufficient to induce changes in MHC composition.
PMID: 18787090 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/pubmed/18787090
The anabolic potential of dietary protein intake on skeletal muscle is prolonged by prior light-load exercise.
Bechshoeft R, Dideriksen KJ, Reitelseder S, Scheike T, Kjaer M, Holm L.
Source
Institute of Sports Medicine, Dept. of Orthopedic Surgery M81, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
Abstract
BACKGROUND & AIMS:
Hyperaminoacidemia stimulates myofibrillar fractional synthesis rate (myoFSR) transiently in resting skeletal muscle. We investigated whether light-load resistance exercise can extent this responsiveness.
METHODS:
Ten healthy males exercised one leg with a light-load resistance-like exercise at 16% of 1 repetition maximum and received oral protein boluses every hour for a 10-h period. Their myoFSR was determined by [1-(13)C]-leucine incorporation. Muscle biopsies were obtained from the resting (REST) and exercised (EXC) muscles every 2.5-h in the protein-fed period.
RESULTS:
Protein feeding significantly elevated plasma leucine and essential amino acids by an average of 39 ± 9% (mean ± SEM) and 20 ± 4%, respectively, compared to the basal concentrations: 197 ± 12 μmol L(-1) and 854 ± 35 μmol L(-1), respectively. The myoFSR was similar in EXC and REST muscles in the first 8 h (all time intervals p > 0.05). After 8 h the myoFSR dropped in the REST muscle to 0.041 ± 0.005%·h(-1), which was 65 ± 5% of the rate in EXC leg at the same time point (0.062 ± 0.004%·h(-1)) and 80 ± 14% of the level in REST leg from 0.5 to 8 h (0.056 ± 0.005%·h(-1)) (interaction p < 0.05).
CONCLUSIONS:
Compared to rest, light-load exercise prolonged the stimulatory effect of dietary protein on muscle biosynthesis providing perspectives for a muscle restorative effect in clinical settings where strenuous activity is intolerable.
Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
PMID: 22867749 [PubMed - as supplied by publisher]
Source: http://www.ncbi.nlm.nih.gov/pubmed/22867749
Source: http://www.ironmagazine.com/2013/tra...pplementation/
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