People may be reacting to varying degrees of energy loss during aerobic exercises and this may be due to their genetic predisposition. How our bodies react to exercise programs is genetic in origin and may decide lot of reactions to exercising like the level of blood glucose in the body etc.
According to the research paper publishing the works of scientists from Washington University School of Medicine, exercise can help the scientists identify regions in chromosomes 6, 7 and 19 that are linked to pre-diabetes.
Pre-diabetes or the condition of glucose intolerance precedes the condition of diabetes. Patients in this condition may not experience the type 2 diabetes that reduces the body's ability to store calories and resulting in high blood sugar count in the blood. But the signs may still exist in the patient's body for many years before the actual symptoms can be experienced.
Researchers had taken families of non-diabetic and sedentary lifestyle for a supervised lifestyle consisting of aerobic exercise programs for a period of 20 weeks. They had prepared measurements of insulin action and glucose metabolism at the start of the program and then again after it were done. The results had shown that insulin sensitivity of the participants has improved but the results were dependent on the families they belong to.
Reference: Diabetologia, June 2005