title: Acute supra-therapeutic oral terbutaline administration has no ergogenic effect in non-asthmatic athletes.
abstract: This study aimed to investigate the effects on a possible improvement in aerobic and anaerobic performance of oral terbutaline (TER) at a supra-therapeutic dose in 7 healthy competitive male athletes. On day 1, ventilatory threshold, maximum oxygen uptake [Formula: see text] and corresponding power output were measured and used to determine the exercise load on days 2 and 3. On days 2 and 3, 8 mg of TER or placebo were orally administered in a double-blind process to athletes who rested for 3 h, and then performed a battery of tests including a force-velocity exercise test, running sprint and a maximal endurance cycling test at Δ50 % (50 % between VT and [Formula: see text]). Lactatemia, anaerobic parameters and endurance performance ([Formula: see text] and time until exhaustion) were raised during the corresponding tests. We found that TER administration did not improve any of the parameters of aerobic performance (p > 0.05). In addition, no change in [Formula: see text] kinetic parameters was found with TER compared to placebo (p > 0.05). Moreover, no enhancement of the force-velocity relationship was observed during sprint exercises after TER intake (p > 0.05) and, on the contrary, maximal strength decreased significantly after TER intake (p < 0.05) but maximal power remained unchanged (p > 0.05). In conclusion, oral acute administration of TER at a supra-therapeutic dose seems to be without any relevant ergogenic effect on anaerobic and aerobic performances in healthy athletes. However, all participants experienced adverse side effects such as tremors.
authors: Faculté des Sciences du Sport, Université Montpellier Sud-de-France, 700 avenue du Pic Saint Loup, Montpellier, France. anthony.sanchez@univ-montp1.fr
authors: Anthony M J
authors: AM
authors: Sanchez
authors: Fabio
authors: F
authors: Borrani
authors: Marie Amélie
authors: MA
authors: Le Fur
authors: Anais
authors: A
authors: Le Mieux
authors: Virgile
authors: V
authors: Lecoultre
authors: Guillaume
authors: G
authors: Py
authors: Christophe
authors: C
authors: Gernigon
authors: Katia
authors: K
authors: Collomp
authors: Robin
authors: R
authors: Candau
mesh_terms: D000284:Administration, Oral; D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage; D000328:Adult; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology; D054874:Athletic Performance / Q000502:physiology*; D001993:Bronchodilator Agents / Q000008:administration & dosage; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D058573:Performance-Enhancing Substances / Q000008:administration & dosage*; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology*; D013726:Terbutaline / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D001993:Bronchodilator Agents; D058573:Performance-Enhancing Substances; D013726:Terbutaline