Have you ever had a doctor write you a prescription  for three laps around a local trail ? How about a prescription for sit-ups? These treatments may not be as typical as the drugs that are usually used to treat our problems, but maybe they should be: a new report shows that regular exercise can be just as effective as prescription drugs for patients with depression and anxiety. "Individuals who exercise report fewer symptoms of anxiety and depression, and lower levels of stress and anger, " said the paper's co-author, Jasper Smith, director of the Anxiety Research and Treatment Program at Southern Methodist University. " Exercise may help patients with depression re-establish positive behaviors. For patients with anxiety disorders, exercise reduces their fears of fear and related bodily sensations such as a racing heart and rapid breathing." In a separate study, published in Physical Therapy journal, scientists studied 161 women who' d recently given birth to babies, and decided them into two groups. New mothers tend to develop post-partum depression , and the scientists wanted to find out whether exercise could prevent such problems. One group of women was given specialized exercises as part of an eight-week parenting education program, while the other was given only written education. The physical element seemed to do the trick; the researchers report that the number of women identified as "at risk" for post-partum depression was reduced by half in the exercising group. Another recent study shows that even when a patient has a chronic illness like cancer or a heart condition, regular exercise can dramatically increase wellbeing by reducing anxiety. Researchers from University of Georgia analyzed 40 clinical trials involving almost 3,000 patients, and found that the patients who reported exercising regularly had a 20% reduction in symptoms of anxiety compared to those who didn't exercise. As a result, they were more likely to follow their recommended treatment plan. Of course, there are still some situations where prescription drugs are necessary, and we recommend you leave it to your doctor to determine when that may be. But in many cases, the best medicine may simply be to get up off the couch and go for a walk. Why does the writer mention another two studies?
To compare the two studies to find their similarities. To prove the theory: regular exercise can reduce people's depression and anxiety. To compare Jasper Smith's study with the two ones. To help those suffering from depression and anxiety get rid of them.