December 17, 2013
News Review From Harvard Medical School -- Running May Reduce Harm of Overeating
Vigorous exercise can help keep those holiday cookies from harming your health, a new study shows. The study included 26 healthy young men. They were asked to limit their normal physical activity for a week. But half of the men were randomly assigned to run on a treadmill for 45 minutes a day. All of the men were asked to follow their normal diet but eat more for of it. Daily calories increased by 50% in the inactive group and 75% in the exercise group. This ensured that both groups had the same excess calorie intake, even though one group was exercising. After just a week of overeating, everyone had an increase in blood sugar. Tests showed that the men also had unhealthy changes to metabolism. But all of these effects were much reduced in the men who were exercising. The Journal of Physiology published the study December 15. HealthDay News wrote about it.
By Reena L. Pande, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
The holidays can be a challenging time to maintain a healthy lifestyle. Most of us know all too well how easy it is to put our healthy habits aside and fall prey to eating poorly and not exercising enough. But there is hope.
An intriguing study published this week in the Journal of Physiology shows that exercise can counter the bad effects of eating poorly.
That may seem like an obvious conclusion. But the researchers used measures of energy metabolism in blood and fat tissue to prove the point. They asked 26 young active men to overeat for one week. Half of them were asked to limit their physical activity. The others were instructed to run on a treadmill for 45 minutes every day.
The men who exercised vigorously had several positive effects that largely balanced out the bad effects of overeating. For example, the exercising group had near-normal blood sugar control. Their fat cells also had positive changes in the genes that affect healthy metabolism.
What Changes Can I Make Now?
Unfortunately, the average adult nowadays eats too much and exercises too little. These bad habits tend to be worse during the holidays. Celebrations bring lots of food and often lead to overeating. Busy schedules and travel during the holidays also can get in the way of regular exercise.
Still, this research is encouraging. It suggests that daily vigorous exercise can counter the negative effects of eating too many holiday goodies. Here are some other ideas on what you can do to stay healthy during this season:
1. Stick to your good habits. Of course, most important is that you try your best to stay with your healthy eating habits. Remember these tips:
- Limit your portion size. Maybe you really want to eat that stuffing? Go for it. But make sure you have only one serving, and a small serving at that.
- Limit sugary drinks. Substitute diet soda, seltzer or water for regular soda, juices and other sugar-sweetened beverages.
- Limit sweets. It's hard to avoid desserts during the holidays. But be aware and try to limit how much you eat.
2. Move! Get some exercise, any exercise. If you already are active, try to keep up with your regular routine. If you don't usually get any exercise, try to do at least some activity. Go for a walk or maybe a hike, or anything you enjoy.
What Can I Expect Looking to the Future?
We have long known that exercise is good for us. Science continues to help us understand exactly why. Researchers study sugar and insulin levels in the blood and genes in the fat cells to better understand why exercise is of such great benefit.
In the case of this study, the benefits help to counter the bad effects of eating too much. However this actually happens in the body, the message is loud and clear. Exercise is good for you, plain and simple. This holiday season, make sure you keep exercise part of your holiday traditions.