As the saying goes: life is about exercise. Exercise can improve insulin resistance, reduce the risk of stroke, and slow down osteoporosis. At the same time, exercise can drive away worries and rejuvenate the spirit. Patients with depression usually take an antidepressant – a selective 5hydroxytryptamine reuptake inhibitor – and for patients with poor outcomes a combination of anxiolytics, antipsychotics, sedative-hypnotics, and herbal prescription drugs are used. These drugs bring therapeutic effects with increased medication costs and increased side effects for patients. In order to improve the state of depression, doctors usually ask patients to exercise regularly according to their physical condition, which is a strength that antidepressant drugs do not have. Exercise is a treatment with almost no side effects and is inexpensive. Researchers have found that for the vast majority of depressed patients who don’t exercise regularly, physician-prescribed exercise as a supplement to medication can provide effective relief, and the more exercise (on its own terms), the greater the degree of symptom relief. The mystery of how exercise can improve mood may lie in phenylethylamine. Phenylethylamine is a chemical naturally produced by the body and has been thought to play a role in regulating physical performance, mood and concentration. An enzyme secreted in the body converts it into phenylacetic acid. The results of studies obtained show that patients suffering from depression have very low levels of both phenylethylamine and phenylacetic acid. However, the effect of exercise on the level of phenylethylamine varies from person to person.