title: Carbohydrate supplementation attenuates decrement in performance in overtrained rats.
abstract: Carbohydrate ingestion at the end of a single exercise is recognized as delaying fatigue and accelerating recovery, but whether chronic ingestion can prevent overtraining during periods of intense training has not yet been elucidated. This study aimed to determine whether carbohydrate supplementation minimizes overtraining in Wistar rats. The animals underwent 11 weeks of training (running) on a treadmill, and the last 3 weeks were designed to induce overtraining. One group was supplemented with carbohydrates (EX-CHO) (n = 13), 1 group had no supplementation (EX) (n = 10), and a third group remained inactive (C) (n = 9). Performance tests were given before training (Pr1) and at the 8th (Pr2) and 11th (Pr3) training week. Food intake, body weight, testosterone, cortisol, malondialdehyde, creatine kinase, and activities of the PI3-K, Akt-1, mTOR, and GSK-3 enzymes were measured. In the EX group, there was a significant 32.6% performance decrease at Pr3 when compared with Pr2. In addition, at protocol completion, the EX-CHO group had a greater gastrocnemius weight than did the C group (p = 0.02), which the EX group did not. Training caused anorexia, decreased testosterone (p = 0.001), and increased malondialdehyde (p = 0.009) in both exercise groups compared with the C group, with no influence of carbohydrate supplementation on these variables (p > 0.05). Compared with in the C group, the activity of Akt-1 was higher in the EX-CHO group but not in the EX group (p = 0.013). Carbohydrate supplementation promoted an attenuation in the performance decrement and maintained gastrocnemius muscle mass in animals that had undergone overtraining protocols, which was accompanied by increased activity of the Akt-1 molecular indicator.
authors.affiliation: a Nutrition Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Caio Victor
authors.initials: CV
authors.lastname: Coutinho de Oliveira
authors.affiliation: a Nutrition Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Carlos Vinícius
authors.initials: CV
authors.lastname: Barbosa
authors.affiliation: a Nutrition Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Nayara Moreira
authors.initials: NM
authors.lastname: Massa
authors.affiliation: b Physical Education Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Reabias de Andrade
authors.initials: Rde A
authors.lastname: Pereira
authors.affiliation: b Physical Education Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Gustavo da Silva
authors.initials: Gda S
authors.lastname: Félix
authors.affiliation: a Nutrition Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Jailane de Souza
authors.initials: Jde S
authors.lastname: Aquino
authors.affiliation: c Biodynamic of the Movement of the Human Body Department, University of São Paulo, 05508900 São Paulo, São Paulo, Brazil.
authors.forename: Edilamar Menezes
authors.initials: EM
authors.lastname: de Oliveira
authors.affiliation: b Physical Education Department, Federal University of Paraíba, João Pessoa, Paraíba 58051-900, Brazil.
authors.forename: Alexandre Sérgio
authors.initials: AS
authors.lastname: Silva
mesh_terms: D000818:Animals; D001835:Body Weight; D003402:Creatine Kinase / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D019587:Dietary Supplements; D038362:Glycogen Synthase Kinase 3 / Q000097:blood; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012420:Running / Q000502:physiology; D013739:Testosterone / Q000097:blood
chemical_list: D004040:Dietary Carbohydrates; D013739:Testosterone; D008315:Malondialdehyde; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3; D003402:Creatine Kinase; D006854:Hydrocortisone
keywords: Akt-1; carbohydrate; exercice physique; exercise; overtraining; performance; rats; sucres; surentraînement