居然是真的，一直以为是心理作用而已 ：）

The Cure for Exhaustion? More Exercise （ZT）

When a person is sapped by fatigue, the last thing he or she wants to do is exercise. But new research shows that regular, low-intensity exercise may help boost energy levels in people suffering from fatigue.

Fatigue is one of the most common health symptoms and can be a sign of a variety of medical problems. However, about one in four people suffers from general fatigue not associated with a serious medical condition.

University of Georgia researchers decided to study whether exercise can be used to treat fatigue. The research, which appears in the February issue of the journal Psychotherapy and Psychosomatics, involved 36 volunteers who were not regular exercisers but who complained of persistent fatigue.

One group of fatigued volunteers was prescribed 20 minutes of moderate-intensity aerobic exercise three times a week for six weeks. The second group engaged in low-intensity aerobic exercise for the same time period, while a third control group did not exercise.

The study volunteers used exercise bikes that allowed the researchers to control their level of exertion. The low-intensity exercise was equivalent to a leisurely, easy walk. The more intense exercise was similar to a fast-paced walk up hills. Patients with fatigue due to serious medical conditions, such as those with chronic fatigue syndrome, weren’t included in the study.

Both of the exercise groups had a 20 percent increase in energy levels by the end of the study, compared to the control group. However, the researchers found that more intense exercise isn’t the best way to reduce fatigue. The low-intensity group reported a 65 percent drop in feelings of fatigue, compared to a 49 percent drop in the group doing more intense exercise.

“Too often we believe that a quick workout will leave us worn out — especially when we are already feeling fatigued,” said researcher Tim Puetz, who recently completed his doctorate at the university and is the lead author of the study. “However, we have shown that regular exercise can actually go a long way in increasing feelings of energy — particularly in sedentary individuals.”

Why exercise helps fatigue isn’t clear, but Dr. Puetz said his findings suggest exercise acts directly on the central nervous system to increase energy and reduce fatigue. Notably, the improvements in energy and fatigue were not related to increases in aerobic fitness.

“A lot of people are overworked and not sleeping enough,” said Patrick O’Connor, co-director of the university’s exercise psychology laboratory. “Exercise is a way for people to feel more energetic. There’s a scientific basis for it, and there are advantages to it compared to things like caffeine and energy drinks.”