The holidays are a time of indulgence, and quite often, our workout gets pushed to the wayside in favor of food, friends, and alcohol. But how much damage can a brief break do? As it turns out, a lot.
A study published in The Journal of Physiology considered the significance of exercising daily during periods of high caloric consumption.
Researchers at the University of Bath in England followed a group of 26 healthy young men with an average age of 25 and divided the men into two distinct study groups.
The first group was instructed to run on a treadmill at moderate intensity for 45 minutes daily, and the second group was not given an exercise regimen. Both groups were instructed to restrict their physical activity from an average of about 10,000 steps per day to fewer than 4,000 steps each day.
“If you are facing a period of overconsumption and inactivity, a daily bout of exercise will prevent many of the negative changes, at least in the short term.”
While the exercise group was to exclude the steps taken during their workout, this meant that during non-exercise times, both groups were equally sedentary.
All participants were also put on a diet plan that increased their net caloric intake by 50%. For the exercise group, the diet included 75% more calories than usual to offset the calories expended during exercise.
In the end, both groups saw the same net daily energy surplus, or excess calories. The study period continued for seven days, after which all participants were tested for insulin levels and had a biopsy taken of their fat tissue.
Testing revealed that the sedentary group saw a substantial decline in blood glucose control, and biopsied fat cells appeared to be overexpressing, or producing in excess, a number of genes linked to unhealthy metabolism and underexpressing other genes crucial for optimal metabolism.
The exercise group, however, did not see these variations. Their blood glucose control stayed healthy and their fat cells showed fewer changes in gene expression compared to the non-exercise group.
The results seem to indicate that the effects of overeating and being sedentary have on the metabolism are complex and can even affect genes on top of physiology. Researchers note that further study is needed but hypothesize that differences in how participants’ bodies metabolize carbohydrates and fats or the release of molecules from exercising muscles might be a factor. They also suggest that these findings may apply to other groups such as women and older adults.
Dr. Dylan Thompson, professor of Health Sciences and member of the University of Bath’s Sport, Health and Exercise Science Research Group, reminds us that “if you are facing a period of overconsumption and inactivity, a daily bout of exercise will prevent many of the negative changes, at least in the short term.”
The Bottom Line
This news is timely as we head into the 6-week-long period of excess that starts with Thanksgiving and ends with the New Year.
On the heels of this study was another one suggesting that if you’re hoping to counter all those extra calories between now and the year-end, exercise won’t help to keep off the pounds. In the study, 148 participants were followed for 6 weeks between Thanksgiving and New Year’s. Half reported being physically active; the others were couch potatoes.
At the end of the holiday period, those who started out obese had the biggest increases in weight gain. In fact, starting weight was the best predictor of how much weight and body fat a person gained. But even in those who were active, exercise had no significant impact on holiday weight gain.
Exercise boosts appetite, which can lead to more overeating; this may explain why the exercisers still gained weight. But it’s likely that the reason for the weight gain was that the excessive eating couldn’t make up for the extra calories burned by exercise.
For example, 45 minutes on the elliptical burns 400 or so calories. However, just one piece of pecan pie with whipped cream will put you in a 200-calorie surplus. Attend a few parties, attend a work holiday party, or snack on some holiday cookies and these extra empty calories really add up.
So, what does this mean for us partygoers during the holidays? While it’s important to enjoy the traditions and foods of the holidays, you’ll need to use some moderation if you don’t want to gain the typical 1 to 2 pounds during this period.
If you really love eggnog, opt for the light version or have a small glass. Stay away from the chips and salsa, and instead, load up on crudités with hummus. Play hostess so that you’re too busy entertaining to drink or eat too much. For other ideas, see our article, 25 Holiday Weight Maintenance Tips.
David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.