Another Reason to Turkey Trot!

A new research study (pubmed, NYTimes) provides evidence that, when you over eat, exercising can counteract some of the negative effects of over consumption.  At least in the short-term.

I love that this study was E-published, ahead of print, three days before America's day of purposeful overindulgence: Thanksgiving.  Just another reason why running in your local Turkey Trot 5K is a great idea.

The details
The study enrolled 26 healthy men and asked them to over eat for a week.  Half of the men were made to run for 45 minutes, every day, at 70% VO2 max (i.e. "vigorous intensity").  The other half were told to not exercise.  At the end of the week, the non-exercise group had elevated fasting blood sugar and other indicators of metabolic syndrome were present in their fat cells.  This did not occur in the exercise group.

Because I am such a geek, I looked up each gene on NCBI to elucidate it's role in metabolism.

In the non-exercise group who overate, expression of these "unhealthy" genes were up-regulated:
SREBP1c - induces the insulin signal; is considered a "thrify gene"; may participate in "fatty liver"
FAS - cell surface death receptor; has been implicated in various cancers
GLUT4 - insulin-regulated glucose transporter; helps glucose enter all cells of the body (Note: exercise allows glucose to enter the cell without insulin!)

And expression of these "healthy" genes were down-regulated:

PDK4 - contributes to glucose regulation

IRS2 - mediates the effects of insulin
HSL - a key enzyme in fatty acid mobilization and lipolysis (i.e. helps you burn fat)
VISFATIN - helps in regulation of glucose homeostasis (i.e. helps your blood sugar stay at a healthy level)

Overeating and physical inactivity can both result in unhealthy metabolic changes (e.g. weight gain, elevated blood sugar, etc).  This study indicates that exercise can help prevent these metabolic changes from occurring, at least in the short-term.  Let us remember that the exercise group was still over eating, probably still gaining weight.  It was the 45 minutes of daily vigorous activity that counteracted the unhealthy metabolic effects.

Moral of the story: if you know you know you are going to over eat, be active!