When many people take vacations, they often take a vacation from their exercise routines as well. But this may not be such a good idea after all. According to two new studies, significantly reducing physical activity for two weeks led to immediate negative metabolic consequences.
The first study consisted of healthy 45-year-old adults, who accumulated at least 10,000 steps per day. Over the course of two weeks, the participants were instructed to decrease their activity to less than 2,000 steps per day, and to increase their sedentary time by three-and-a-half hours. Immediately after the sedentary period, measurements were taken. They showed an increase in blood-sugar levels, a decrease in insulin sensitivity, a worsened cholesterol profile, a decrease in muscle mass in the legs, and an increase in fat around the abdomen. Participants were then instructed to resume their normal physical activity prior to the study. After two weeks of their normal activity, measurements were taken again. For most of the participants, all of the negative consequences of their two weeks of inactivity had reversed. For a few, however, these markers had not completely gotten back to their pre-intervention levels.
The second study included 65-year-old participants who were at risk of developing type 2 Diabetes due to high blood sugar levels, but were otherwise healthy, walking between 7,000-8,000 steps per day. They were told to decrease their activity to less than 1,000 steps per day, for two weeks, and measurements were taken afterwards. Again, blood sugar levels were worse, insulin resistance increased, there was a negative change in muscle tissue, and some participants had to be removed from the study due to developing type 2 Diabetes. After the two weeks of inactivity, they resumed their normal activity, and were measured two weeks after that. Most participants did not reverse the negative metabolic changes that had resulted from their two weeks of inactivity, even after resuming normal activity.
There are several things to learn from these studies. Taking even a couple of weeks off from exercise can yield negative physiological consequences even in healthy adults, which can sometimes be reversed when exercise is resumed. When older adults take a break from exercise, even after they resume, many of the negative consequences from their previous sedentary behaviors are not soon fully reversed. It appears that the older we get, the harder it becomes to undo the negative effects of inactivity. Even while on vacation, it can be easy to find ways to be physically active, while taking time to relax. Playing tennis, taking a walk on the beach, and riding bikes can all be enjoyable holiday activities. The bottom line is to keep on moving, and if you stop for any reason, resume as soon as possible.