Hypertrophic effect of inhaled beta2 -agonist with and without concurrent exercise training: A randomized controlled trial.
Scand J Med Sci Sports
; 28(10): 2114-2122, 2018 Oct.
Article
em En
| MEDLINE
| ID: mdl-29777633
ABSTRACT
Due to a high prevalence of asthma and exercise-induced bronchoconstriction in elite athletes, there is a high use of beta2 -adrenoceptor agonists (beta2 -agonists) in the athletic population. While anabolic in rodents, no study has been able to detect hypertrophy in humans after chronic beta2 -agonist inhalation. We investigated whether inhaled beta2 -agonist, terbutaline, alters body composition and metabolic rate with and without concurrent exercise training in healthy young men. Sixty-seven participants completed a 4-week intervention of daily terbutaline (8 × 0.5 mg) or placebo treatment without concurrent training (habitual; n = 23), with resistance (n = 23) or endurance (n = 21) training 3 times weekly. Before and after the interventions, participant's body composition was determined by dual-energy X-ray absorptiometry and resting metabolic rate and substrate oxidation by indirect calorimetry. Terbutaline increased lean body mass by 1.03 kg (95% CI 0.29-1.76; P < .05) and 1.04 kg (95% CI 0.16-1.93; P < .05) compared to placebo in the habitual and resistance training group, respectively, but had no effect compared to placebo in the endurance training group [-0.56 kg (95% CI -1.74-0.62; P > .05)]. Fat mass, bone mineral content, and resting metabolic rate did not change differently between treatments with the intervention. Daily inhalation of terbutaline in near-therapeutic doses induces skeletal muscle growth. This observation should be a concern for antidoping authorities.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Terbutalina
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Composição Corporal
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Exercício Físico
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Músculo Esquelético
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Agonistas de Receptores Adrenérgicos beta 2
Tipo de estudo:
Clinical_trials
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Risk_factors_studies
Limite:
Adult
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Humans
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Male
Idioma:
En
Revista:
Scand J Med Sci Sports
Assunto da revista:
MEDICINA ESPORTIVA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Dinamarca