That’s right! Your treadmill could be contributing to your trouble losing weight. Of course, many factors can be blamed for failure to lose weight; however, until recently your treadmill was not one of them. Exercise was always considered essential to weight loss. That is still true but the type and length of exercise may need to be revised.
The reason your treadmill is getting bad press relates to stress and the overproduction of cortisol. New research has discovered that long jogs or exercise sessions on the treadmill can actually increase cortisol. And, increased cortisol works against weight loss. Excess cortisol stops your body from burning fat for energy. Without a good way of burning fat for energy, losing weight becomes an uphill battle.
Working long hours without taking breaks, sleeping less time than you personally need, and thinking and worrying all the time are major causes of the overproduction of cortisol. The last thing most of us want is to exercise 20 or 30 minutes on our treadmill thinking we are helping ourselves to lose weight only to find out that we have burned relatively few calories and that we have produced more cortisol.
Actually, the relationships between exercise and cortisol and weight loss are tricky. There is not one simple answer for all. Cortisol is released in response to stress. If you are not in shape and just beginning an exercise program, even walking at a 20- minutes-per-mile pace can cause you to release extra cortisol. However, as your exercise training progresses, that 20-minutes- per-mile pace may not be as stressful and thus, you will not release as much cortisol. But, if you exercise until you use up your body’s glycogen stores, then you will cause an added release of cortisol to use as fuel. More is not always better. Short bursts of intense exercise may be better for weight loss without adding cortisol.
More Good News About the Benefits of Exercise
The training effect of exercise is not limited to improving your body’s physical reaction to stress. People who are active and exercise on a regular basis show a significantly lower cortisol response to an emotional crisis when compared to sedentary controls. Dr. Rimmele and colleagues at the University of Zurich in Switzerland have published a number of recent studies on how exercise training reduces salivary cortisol and cardiac stress indicators, such as heart rate. The surprising finding of Dr. Rimmele’s study – and a good take-home message for psychologists working with clients who are easily upset and/or who have some social anxiety – is that physical exercise also reduces salivary cortisol when a person is stressed in social or emotional situations. So don’t give away that treadmill after all, just use it wisely.
In the next Stress Solutions Column, we look at how important sleep is in losing weight.
by Susan Andrews, PhD
The Psychology Times, August 2014
Dr. Susan Andrews, Clinical Neuropsychologist, is currently Clinical Assistant Professor, LSU Health Sciences Center, Department of Medicine and Psychiatry, engaged in a Phase III study on HBOT and Persistent PostConcussion Syndrome. In addition to private clinical practice, Dr. Andrews is an award-winning author of Stress Solutions for Pregnant Moms (2013).