The investigators have previously shown that mild exercise training at the level of lactate threshold (LT) intensity (60 min/day, 5 days/week) improves peripheral insulin sensitivity and insulin-independent glucose disposal of glucose effectiveness, without changes in body weight and body fat (Nishida et al, Diabetes Care, 2001; Nishida et al, Diabetes, 2004). Thus these beneficial effects are likely related to a number of adaptations that occur in skeletal muscle as response to exercise. In the current study, the investigators hypothesised that a single bout of mild exercise performed at LT would be a physiological stimulator of skeletal muscle PGC-1alpha gene, and the repetition of this exercise stimulating PGC-1alpha gene (i.e., training) for 12 weeks would induce coordinated increases in a large number of metabolic genes, as well as other genes potentially important in the prevention of insulin resistance and metabolic syndrome.

Inclusion Criteria:

• Men who were all in good health
• All individuals were free from diabetes and none were taking any medications
• All subjects were asked not to change their normal dietary habits, and not to engage in any strenuous physical activity

Exclusion Criteria:

• People who undergone regular exercise for at least 2 years
• Smokers