Treadmill training improves intravenous glucose tolerance and insulin sensitivity in fatty Zucker rats

The effect of treadmill training on intravenous glucose tolerance and insulin sensitivity was investigated in Zucker rats (fafa). In 25-week-old fafa animals with the typical metabolic syndrome of massive obesity, glucose intolerance, hypertriglyceridaemia and insulin resistance, treadmill exercise of only very mild intensity was carried out for 6 weeks. The training programme induced a marked reduction in basal and post-glucose challenge plasma insulin levels and a slight but significant improvement of intravenous glucose tolerance. No alteration in insulin sensitivity of the isolated perfused hindquarter was demonstrable. In another study a 9-week training programme was started in 7-week-old fafa rats before the development of their metabolic syndrome. In the sedentary control animals glucose intolerance and insulin resistance developed during the study period; in the training group, both the deterioration of glucose tolerance and the decrease of insulin sensitivity were prevented. This study demonstrates in fafa rats that (a) in young animals physical training may prevent a genetically predisposed deterioration of glucose tolerance and insulin sensitivity and (b) in adult animals mild physical training may improve intravenous glucose tolerance and insulin sensitivity.