After only a week, the young men who had not exercised displayed a significant and unhealthy decline in their blood sugar control, and, equally worrying, their biopsied fat cells seemed to have developed a malicious streak. Those cells, examined using sophisticated genetic testing techniques, were now overexpressing various genes that may contribute to unhealthy metabolic changes and underexpressing other genes potentially important for a well-functioning metabolism.<idle musing>
But the volunteers who had exercised once a day, despite comparable energy surpluses, were not similarly afflicted. Their blood sugar control remained robust, and their fat cells exhibited far fewer of the potentially undesirable alterations in gene expression than among the sedentary men.
This is basically what Covert Bailey has been saying for over 35 years. Exercise doesn't just burn calories (it actually burns very few), it realigns the body's metabolism so that your muscles become "better butter burners" as he puts it.