There was no statistical increase in muscle citrate synthase activity in any group with training (HO p=0.120, HY p=0.682 and COPD p=0.133), but following 4 weeks of exercise withdrawal citrate synthase activity in COPD was less than baseline (p=0.015) and 8 weeks of training (p<0.001) (figure 2a). The gene discussed is CS; the disease is chronic obstructive pulmonary disease.