Fasting: a major limitation for resistance exercise training effects in rodents

Autor(es)

W. das Neves ^[1] ; L.F. de Oliveira ^[1] ; R.P. da Silva ^[1] ; C.R.R. Alves ^[1] ; A.H. Lancha Jr. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Educ Fis & Esporte, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Medical and Biological Research; v. 51, n. 1 2017-11-17.

Resumo

Protocols that mimic resistance exercise training (RET) in rodents present several limitations, one of them being the electrical stimulus, which is beyond the physiological context observed in humans. Recently, our group developed a conditioning system device that does not use electric shock to stimulate rats, but includes fasting periods before each RET session. The current study was designed to test whether cumulative fasting periods have some influence on skeletal muscle mass and function. Three sets of male Wistar rats were used in the current study. The first set of rats was submitted to a RET protocol without food restriction. However, rats were not able to perform exercise properly. The second and third sets were then randomly assigned into three experimental groups: 1) untrained control rats, 2) untrained rats submitted to fasting periods, and 3) rats submitted to RET including fasting periods before each RET session. While the second set of rats performed a short RET protocol (i.e., an adaptation protocol for 3 weeks), the third set of rats performed a longer RET protocol including overload (i.e., 8 weeks). After the short-term protocol, cumulative fasting periods promoted loss of weight (P<0.001). After the longer RET protocol, no difference was observed for body mass, extensor digitorum longus (EDL) morphology or skeletal muscle function (P>0.05 for all). Despite no effects on EDL mass, soleus muscle displayed significant atrophy in the fasting experimental groups (P<0.01). Altogether, these data indicate that fasting is a major limitation for RET in rats. (AU)

• Processo FAPESP: 12/13026-5 - Suplementação de beta-alanina e bicarbonato de sódio: efeitos sobre a utilização dos sistemas energéticos durante o exercício anaeróbio intermitente
• Beneficiário: Rafael Pires da Silva
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/04744-4 - Efeitos do treinamento de força no músculo esquelético em ratos com caquexia induzida pelo câncer
• Beneficiário: Willian das Neves Silva
• Modalidade de apoio: Bolsas no Brasil - Mestrado