β2-adrenergic receptor maladaptations to high power resistance exercise overreaching
- Autores: Sterczala A.1, Fry A.1, Chiu L.2, Schilling B.3, Weiss L.4, Nicoll J.1
-
Afiliações:
- Applied Physiology Laboratory, Department of Health, Sport and Exercise Sciences
- Faculty of Physical Education and Recreation
- Department of Kinesiology and Nutrition Sciences
- Human Performance Laboratories, Department of Health and Sport Sciences
- Edição: Volume 43, Nº 4 (2017)
- Páginas: 446-454
- Seção: Article
- URL: https://journals.rcsi.science/0362-1197/article/view/177240
- DOI: https://doi.org/10.1134/S0362119717040144
- ID: 177240
Citar
Resumo
The effects of a recovery drink on overreaching induced by high frequency, high power resistance exercise was assessed. Resistance trained men were assigned to a supplemented (SUP, n = 8), placebo (PL, n = 3) or control (CON, n = 6) groups. All groups completed two weeks of familiarization training using the barbell squat. In week three, SUP and PL performed ten sets of five repetitions of speed squats twice daily, for a total of 15 training sessions. CON maintained their prior training schedule. Data were collected before week three (T1), after week three (T2) and after a week of recovery by training cessation (T3). During week three, SUP consumed an amino acid, carbohydrate and creatine monohydrate containing recovery drink immediately after each training bout. PL was provided a drink of similar appearance and taste but containing minimal nutritional value. At T2, both SUP and PL decreased mean squat velocity and power at 70% 1RM. Additionally, SUP and PL decreased muscle β2-adrenergic receptor (β2-AR) expression by 61 and 83%, respectively. Increases in the ratio of nocturnal urinary epinephrine/β2-AR ratio (EPI: β2AR) for SUP and PL suggested impaired sympathetic nervous system sensitivity. SUP demonstrated a smaller decrease in β2-AR expression and a lower EPI: β2AR, suggesting the recovery drink attenuated the detrimental effects of overreaching on the sympathetic activity. In conclusion, high power resistance exercise overreaching can induce performance decrements and impair sympathetic activity, but these effects may be attenuated by supplementation.
Palavras-chave
Sobre autores
A. Sterczala
Applied Physiology Laboratory, Department of Health, Sport and Exercise Sciences
Email: acfry@ku.edu
Estados Unidos da América, Lawrence, KS, 66045
A. Fry
Applied Physiology Laboratory, Department of Health, Sport and Exercise Sciences
Autor responsável pela correspondência
Email: acfry@ku.edu
Estados Unidos da América, Lawrence, KS, 66045
L. Chiu
Faculty of Physical Education and Recreation
Email: acfry@ku.edu
Canadá, Edmonton, AB
B. Schilling
Department of Kinesiology and Nutrition Sciences
Email: acfry@ku.edu
Estados Unidos da América, Las Vegas, NV, 89154
L. Weiss
Human Performance Laboratories, Department of Health and Sport Sciences
Email: acfry@ku.edu
Estados Unidos da América, Memphis, TN, 38512
J. Nicoll
Applied Physiology Laboratory, Department of Health, Sport and Exercise Sciences
Email: acfry@ku.edu
Estados Unidos da América, Lawrence, KS, 66045