Purpose: To evaluate the effects of intensity of exercise on insulin resistance and the expression of inflammatory proteins in the skeletal muscle of diet-induced obese (DIO) rats after a single bout of exercise.
Methods: In the first exercise protocol, the rats swam for two 3-h bouts, separated by a 45-min rest period (with 6 h in duration-DIO + EXE), and in the second protocol, the rats were exercised with 45 min of swimming at 70% of the maximal lactate steady state-MLSS (DIO + MLSS).
Results: Our data demonstrated that both protocols of exercise increased insulin sensitivity and increased insulin-stimulated tyrosine phosphorylation of insulin receptor and insulin receptor substrate 1 and serine phosphorylation of protein kinase B in the muscle of DIO rats by the same magnitude. In parallel, both exercise protocols also reduced protein tyrosine phosphatase 1B activity and insulin receptor substrate 1 serine phosphorylation, with concomitant reduction in c-jun N-terminal kinase and IκB kinase activities in the muscle of DIO rats in a similar fashion.
Conclusions: Thus, our data demonstrate that either exercise protocols with low intensity and high volume or exercise with moderate intensity and low volume represents different strategies to restore insulin sensitivity with the same efficacy.
1Department of Internal Medicine, Faculty of Medical Sciences State University of Campinas - UNICAMP, Campinas, São Paulo, BRAZIL; 2School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, BRAZIL; 3Department of Bioscience, Faculty of Physical Education, Federal University of São Paulo - UNIFESP, Santos, SP, BRAZIL; and 4Exercise Biochemistry and Physiology Laboratory Postgraduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciuma, Santa Catarina, BRAZIL
Address for correspondence: Adelino Sanchez Ramos da Silva, Avenida Bandeirantes, 3900, Monte Alegre, 14040-900, Ribeirão Preto, São Paulo, Brazil (Rua das Paineiras, Casa 01); E-mail: firstname.lastname@example.org.
Submitted for publication December 2009.
Accepted for publication April 2010.